Enable Hidden Administration Feature displaying All Site Settings

Tested on: WordPress 3.1 RC3

This little piece of code does something pretty cool. It will add an additional option to your settings menu with a link to "all settings" which will show you a complete list of all the settings you have within your database related to your WordPress site. The code below will only made this link visible to an administrator user and hide it for all other users.

// CUSTOM ADMIN MENU LINK FOR ALL SETTINGS
   function all_settings_link() {
    add_options_page(__('All Settings'), __('All Settings'), 'administrator', 'options.php');
   }
   add_action('admin_menu', 'all_settings_link');

Modify the Login Logo & Image URL Link

Tested on: WordPress 3.0.1

This code will allow you to easily modify the WordPress Login page Logo as well as the href link and title text of this logo.

add_filter( 'login_headerurl', 'namespace_login_headerurl' );
/**
 * Replaces the login header logo URL
 *
 * @param $url
 */
function namespace_login_headerurl( $url ) {
    $url = home_url( '/' );
    return $url;
}

add_filter( 'login_headertitle', 'namespace_login_headertitle' );
/**
 * Replaces the login header logo title
 *
 * @param $title
 */
function namespace_login_headertitle( $title ) {
    $title = get_bloginfo( 'name' );
    return $title;
}

add_action( 'login_head', 'namespace_login_style' );
/**
 * Replaces the login header logo
 */
function namespace_login_style() {
    echo '<style>.login h1 a { background-image: url( ' . get_template_directory_uri() . '/images/logo.png ) !important; }</style>';
}

EDIT: If you want to use the site logo to replace the login logo, you can use the following to dynamically pull that information (tested on WP3.5):

function namespace_login_style() {
    if( function_exists('get_custom_header') ){
        $width = get_custom_header()->width;
        $height = get_custom_header()->height;
    } else {
        $width = HEADER_IMAGE_WIDTH;
        $height = HEADER_IMAGE_HEIGHT;
    }
    echo '<style>'.PHP_EOL;
    echo '.login h1 a {'.PHP_EOL; 
    echo '  background-image: url( '; header_image(); echo ' ) !important; '.PHP_EOL;
    echo '  width: '.$width.'px !important;'.PHP_EOL;
    echo '  height: '.$height.'px !important;'.PHP_EOL;
    echo '  background-size: '.$width.'px '.$height.'px !important;'.PHP_EOL;
    echo '}'.PHP_EOL;
    echo '</style>'.PHP_EOL;
}

Include custom post types in the search results.

// MAKE CUSTOM POST TYPES SEARCHABLE
function searchAll( $query ) {
 if ( $query->is_search ) { $query->set( 'post_type', array( 'site', 'plugin', 'theme', 'person' )); } 
 return $query;
}
add_filter( 'the_search_query', 'searchAll' );

Add your custom post types to your sites main RSS feed by default.

// ADD CUSTOM POST TYPES TO THE DEFAULT RSS FEED
function custom_feed_request( $vars ) {
 if (isset($vars['feed']) && !isset($vars['post_type']))
  $vars['post_type'] = array( 'post', 'site', 'plugin', 'theme', 'person' );
 return $vars;
}
add_filter( 'request', 'custom_feed_request' );

Include custom post types in "Right Now" admin dashboard widget

This will include your custom post types and the post counts for each type in the "Right Now" dashboard widget.

// ADD CUSTOM POST TYPES TO THE 'RIGHT NOW' DASHBOARD WIDGET
function wph_right_now_content_table_end() {
 $args = array(
  'public' => true ,
  '_builtin' => false
 );
 $output = 'object';
 $operator = 'and';
 $post_types = get_post_types( $args , $output , $operator );
 foreach( $post_types as $post_type ) {
  $num_posts = wp_count_posts( $post_type->name );
  $num = number_format_i18n( $num_posts->publish );
  $text = _n( $post_type->labels->singular_name, $post_type->labels->name , intval( $num_posts->publish ) );
  if ( current_user_can( 'edit_posts' ) ) {
   $num = "<a href='edit.php?post_type=$post_type->name'>$num</a>";
   $text = "<a href='edit.php?post_type=$post_type->name'>$text</a>";
  }
  echo '<tr><td class="first num b b-' . $post_type->name . '">' . $num . '</td>';
  echo '<td class="text t ' . $post_type->name . '">' . $text . '</td></tr>';
 }
 $taxonomies = get_taxonomies( $args , $output , $operator ); 
 foreach( $taxonomies as $taxonomy ) {
  $num_terms  = wp_count_terms( $taxonomy->name );
  $num = number_format_i18n( $num_terms );
  $text = _n( $taxonomy->labels->singular_name, $taxonomy->labels->name , intval( $num_terms ));
  if ( current_user_can( 'manage_categories' ) ) {
   $num = "<a href='edit-tags.php?taxonomy=$taxonomy->name'>$num</a>";
   $text = "<a href='edit-tags.php?taxonomy=$taxonomy->name'>$text</a>";
  }
  echo '<tr><td class="first b b-' . $taxonomy->name . '">' . $num . '</td>';
  echo '<td class="t ' . $taxonomy->name . '">' . $text . '</td></tr>';
 }
}
add_action( 'right_now_content_table_end' , 'wph_right_now_content_table_end' );

Remove Update Notification for all users except ADMIN User

Tested on: WordPress 3.0.1

This code will ensures that no users other than "admin" are notified by WordPress when updates are available..

// REMOVE THE WORDPRESS UPDATE NOTIFICATION FOR ALL USERS EXCEPT SYSADMIN
   global $user_login;
   get_currentuserinfo();
   if ($user_login !== "admin") { // Change admin to the username that gets the updates
    add_action( 'init', create_function( '$a', "remove_action( 'init', 'wp_version_check' );" ), 2 );
    add_filter( 'pre_option_update_core', create_function( '$a', "return null;" ) );
   }

Changed version to only show update notification for admin users (as opposed to just the user 'admin'):

// REMOVE THE WORDPRESS UPDATE NOTIFICATION FOR ALL USERS EXCEPT SYSADMIN
       global $user_login;
       get_currentuserinfo();
       if (!current_user_can('update_plugins')) { // Checks to see if current user can update plugins
        add_action( 'init', create_function( '$a', "remove_action( 'init', 'wp_version_check' );" ), 2 );
        add_filter( 'pre_option_update_core', create_function( '$a', "return null;" ) );
       }

Loading jQuery from the Google CDN

Tested on: WordPress 3.0.1

// Even more smart jQuery inclusion :)
add_action( 'init', 'jquery_register' );

// Register from Google and for footer
function jquery_register() {

    if ( !is_admin() ) {

        wp_deregister_script( 'jquery' );
        wp_register_script( 'jquery', ( 'https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js' ), false, null, true );
        wp_enqueue_script( 'jquery' );
    }
}

Remove the WordPress Version Info for Security

Tested on: WordPress 3.0.1

// Remove version info from head and feeds
function complete_version_removal() {
    return '';
}
add_filter('the_generator', 'complete_version_removal');

Add Spam & Delete Links to Comments on Front End

Tested on: WordPress 3.0.1

This makes it way easier to manage comments from the front end by adding spam and delete links.**

// Spam & delete links for all versions of WordPress
function delete_comment_link($id) {
    if (current_user_can('edit_post')) {
        echo '| <a href="'.get_bloginfo('wpurl').'/wp-admin/comment.php?action=cdc&c='.$id.'">del</a> ';
        echo '| <a href="'.get_bloginfo('wpurl').'/wp-admin/comment.php?action=cdc&dt=spam&c='.$id.'">spam</a>';
    }
}

Delay the public posting to RSS Feed

Tested on: WordPress 3.0.1

Finally, I like to delay posting to my RSS feeds for 10-15 minutes because I always find at least a couple errors in my text. Other uses are in case you want content to be exclusive to your site for a day or a week before pushing it out to your RSS readers.

// Delay feed update
function publish_later_on_feed($where) {
    global $wpdb;

    if (is_feed()) {
        // Timestamp in WordPress format
        $now = gmdate('Y-m-d H:i:s');

        // Value for wait; + device
        $wait = '10'; // integer

        // http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html#function_timestampdiff
        $device = 'MINUTE'; // MINUTE, HOUR, DAY, WEEK, MONTH, YEAR

        // Add SQL syntax to default $where
        $where .= " AND TIMESTAMPDIFF($device, $wpdb->posts.post_date_gmt, '$now') > $wait ";
    }
    return $where;
}
add_filter('posts_where', 'publish_later_on_feed');

Set a maximum number of post revisions to avoid DB bloat.

Tested on: WordPress 3.0.1

The default is infinite, and this will set it to only remember the last five edits:

/**
 * Set the post revisions unless the constant was set in wp-config.php
 */
if (!defined('WP_POST_REVISIONS')) define('WP_POST_REVISIONS', 5);

For what it's worth, there are a ton of great ideas for CONSTANTS that can be set on the Codex page Editing wp-config.php ^[1].

WordPress Profiling tools

I like to add profiling tools in a separate file, which I then include from functions.php when needed:

<?php
    if ( !defined('SAVEQUERIES') && isset($_GET['debug']) && $_GET['debug'] == 'sql' )
        define('SAVEQUERIES', true);

    if ( !function_exists('dump') ) :
        /**
         * dump()
         *
         * @param mixed $in
         * @return mixed $in
         **/

        function dump($in = null) {
            echo '<pre style="margin-left: 0px; margin-right: 0px; padding: 10px; border: solid 1px black; background-color: ghostwhite; color: black; text-align: left;">';
            foreach ( func_get_args() as $var ) {
                echo "\n";
                if ( is_string($var) ) {
                    echo "$var\n";
                } else {
                    var_dump($var);
                }
            }
            echo '</pre>' . "\n";
            return $in;
        } # dump()
    endif;

    /**
     * add_stop()
     *
     * @param mixed $in
     * @param string $where
     * @return mixed $in
     **/

    function add_stop($in = null, $where = null) {
        global $sem_stops;
        global $wp_object_cache;
        $queries = get_num_queries();
        $milliseconds = timer_stop() * 1000;
        $out =  "$queries queries - {$milliseconds}ms";
        if ( function_exists('memory_get_usage') ) {
            $memory = number_format(memory_get_usage() / ( 1024 * 1024 ), 1);
            $out .= " - {$memory}MB";
        }
        $out .= " - $wp_object_cache->cache_hits cache hits / " . ( $wp_object_cache->cache_hits + $wp_object_cache->cache_misses );
        if ( $where ) {
            $sem_stops[$where] = $out;
        } else {
            dump($out);
        }
        return $in;
    } # add_stop()


    /**
     * dump_stops()
     *
     * @param mixed $in
     * @return mixed $in
     **/

    function dump_stops($in = null) {

        if ( $_POST )
            return $in;

        global $sem_stops;
        global $wp_object_cache;
        $stops = '';

        foreach ( $sem_stops as $where => $stop )
            $stops .= "$where: $stop\n";

        dump("\n" . trim($stops) . "\n");

        if ( defined('SAVEQUERIES') && $_GET['debug'] == 'sql' ) {
            global $wpdb;
            foreach ( $wpdb->queries as $key => $data ) {
                $query = rtrim($data[0]);
                $duration = number_format($data[1] * 1000, 1) . 'ms';
                $loc = trim($data[2]);
                $loc = preg_replace("/(require|include)(_once)?,\s*/ix", '', $loc);
                $loc = "\n" . preg_replace("/,\s*/", ",\n", $loc) . "\n";
                dump($query, $duration, $loc);
            }
        }

        if ( $_GET['debug'] == 'cache' )
            dump($wp_object_cache->cache);

        if ( $_GET['debug'] == 'cron' ) {
            $crons = get_option('cron');

            foreach ( $crons as $time => $_crons ) {

                if ( !is_array($_crons) )
                    continue;

                foreach ( $_crons as $event => $_cron ) {
                    foreach ( $_cron as $details ) {
                        $date = date('Y-m-d H:m:i', $time);
                        $schedule = isset($details['schedule']) ? "({$details['schedule']})" : '';
                        if ( $details['args'] )
                            dump("$date: $event $schedule", $details['args']);
                        else
                            dump("$date: $event $schedule");
                    }
                }
            }
        }
        return $in;
    } # dump_stops()
    add_action('init', create_function('$in', '
        return add_stop($in, "Load");
        '), 10000000);
    add_action('template_redirect', create_function('$in', '
        return add_stop($in, "Query");
        '), -10000000);
    add_action('wp_footer', create_function('$in', '
        return add_stop($in, "Display");
        '), 10000000);
    add_action('admin_footer', create_function('$in', '
        return add_stop($in, "Display");
        '), 10000000);

    /**
     * init_dump()
     *
     * @return void
     **/

    function init_dump() {
        global $hook_suffix;
        if ( !is_admin() || empty($hook_suffix) ) {
            add_action('wp_footer', 'dump_stops', 10000000);
            add_action('admin_footer', 'dump_stops', 10000000);
        } else {
            add_action('wp_footer', 'dump_stops', 10000000);
            add_action("admin_footer-$hook_suffix", 'dump_stops', 10000000);
        }
    } # init_dump()
    add_action('wp_print_scripts', 'init_dump');


    /**
     * dump_phpinfo()
     *
     * @return void
     **/

    function dump_phpinfo() {
        if ( isset($_GET['debug']) && $_GET['debug'] == 'phpinfo' ) {
            phpinfo();
            die;
        }
    } # dump_phpinfo()
    add_action('init', 'dump_phpinfo');


    /**
     * dump_http()
     *
     * @param array $args
     * @param string $url
     * @return array $args
     **/

    function dump_http($args, $url) {
        dump(preg_replace("|/[0-9a-f]{32}/?$|", '', $url));
        return $args;
    } # dump_http()


    /**
     * dump_trace()
     *
     * @return void
     **/

    function dump_trace() {
        $backtrace = debug_backtrace();
        foreach ( $backtrace as $trace )
            dump(
                'File/Line: ' . $trace['file'] . ', ' . $trace['line'],
                'Function / Class: ' . $trace['function'] . ', ' . $trace['class']
                );
    } # dump_trace()
    if ( $_GET['debug'] == 'http' )
        add_filter('http_request_args', 'dump_http', 0, 2);
?>

Sharpen Resized Images (only JPEG)

This function sharpens resized JPEG images. An example of a difference:

function ajx_sharpen_resized_files( $resized_file ) {

    $image = wp_load_image( $resized_file );
    if ( !is_resource( $image ) )
        return new WP_Error( 'error_loading_image', $image, $file );

    $size = @getimagesize( $resized_file );
    if ( !$size )
        return new WP_Error('invalid_image', __('Could not read image size'), $file);
    list($orig_w, $orig_h, $orig_type) = $size;

    switch ( $orig_type ) {

        case IMAGETYPE_JPEG:
            $matrix = array(
                array(-1, -1, -1),
                array(-1, 16, -1),
                array(-1, -1, -1),
            );

            $divisor = array_sum(array_map('array_sum', $matrix));
            $offset = 0;
            imageconvolution($image, $matrix, $divisor, $offset);
            imagejpeg($image, $resized_file,apply_filters( 'jpeg_quality', 90, 'edit_image' ));
            break;

        case IMAGETYPE_PNG:
            return $resized_file;

        case IMAGETYPE_GIF:
            return $resized_file;
    }

    return $resized_file;
}

add_filter('image_make_intermediate_size', 'ajx_sharpen_resized_files', 900);

Remove Default WordPress Meta Boxes

Tested on: WordPress 3.0.1

This code will allow you to remove specific Meta Boxes which WordPress adds by default to the default Add/Edit Post and Add/Edit Page screens.

// REMOVE META BOXES FROM DEFAULT POSTS SCREEN
function remove_default_post_screen_metaboxes() {
    remove_meta_box( 'postcustom','post','normal' ); // Custom Fields Metabox
    remove_meta_box( 'postexcerpt','post','normal' ); // Excerpt Metabox
    remove_meta_box( 'commentstatusdiv','post','normal' ); // Comments Metabox
    remove_meta_box( 'trackbacksdiv','post','normal' ); // Talkback Metabox
    remove_meta_box( 'slugdiv','post','normal' ); // Slug Metabox
    remove_meta_box( 'authordiv','post','normal' ); // Author Metabox
}
add_action('admin_menu', 'remove_default_post_screen_metaboxes');


// REMOVE META BOXES FROM DEFAULT PAGES SCREEN
function remove_default_page_screen_metaboxes() {
    remove_meta_box( 'postcustom','page','normal' ); // Custom Fields Metabox
    remove_meta_box( 'postexcerpt','page','normal' ); // Excerpt Metabox
    remove_meta_box( 'commentstatusdiv','page','normal' ); // Comments Metabox
    remove_meta_box( 'trackbacksdiv','page','normal' ); // Talkback Metabox
    remove_meta_box( 'slugdiv','page','normal' ); // Slug Metabox
    remove_meta_box( 'authordiv','page','normal' ); // Author Metabox
}
add_action('admin_menu', 'remove_default_page_screen_metaboxes');

Remove "Wordpress" to "WordPress" filter

Tested on: WordPress 3.0.1

There was a filter added with WordPress version 3.0 that automatically converts all instances of "Wordpress" (no capital P) to "WordPress" (with a capital P) in post content, post titles, and comment text. Some people see this as intrusive, but I just have a need to mis-case WordPress from time to time and found the filter somewhat annoying.

// Remove annoying P filter
if(function_exists('capital_P_dangit')) {
    foreach ( array( 'the_content', 'the_title' ) as $filter )
        remove_filter( $filter, 'capital_P_dangit', 11 );

    remove_filter('comment_text', 'capital_P_dangit', 31 );
}

Customize the Dashboard

add_action('wp_dashboard_setup', 'my_custom_dashboard_widgets');

function my_custom_dashboard_widgets() {
   global $wp_meta_boxes;

Remove these dashboard widgets...

   unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']);
   unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']);
   unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary']);

Add a custom widget called 'Help and Support'

   wp_add_dashboard_widget('custom_help_widget', 'Help and Support', 'custom_dashboard_help');
}

This is the content for your custom widget

 function custom_dashboard_help() {
    echo '<p>Lorum ipsum delor sit amet et nunc</p>';
}

Add Custom User Profile Fields

Place the code below into your functions.php file to add custom user profile fields. Edit or add lines as you see fit.

Remember not to remove the line: return $contactmethods; otherwise this won't work.

// CUSTOM USER PROFILE FIELDS
   function my_custom_userfields( $contactmethods ) {

    // ADD CONTACT CUSTOM FIELDS
    $contactmethods['contact_phone_office']     = 'Office Phone';
    $contactmethods['contact_phone_mobile']     = 'Mobile Phone';
    $contactmethods['contact_office_fax']       = 'Office Fax';

    // ADD ADDRESS CUSTOM FIELDS
    $contactmethods['address_line_1']       = 'Address Line 1';
    $contactmethods['address_line_2']       = 'Address Line 2 (optional)';
    $contactmethods['address_city']         = 'City';
    $contactmethods['address_state']        = 'State';
    $contactmethods['address_zipcode']      = 'Zipcode';
    return $contactmethods;
   }
   add_filter('user_contactmethods','my_custom_userfields',10,1);

To display custom fields you can use one of the two methods listed below.

Option 1:

the_author_meta('facebook', $current_author->ID)

Option 2:

<?php $current_author = get_userdata(get_query_var('author')); ?>
<p><a href="<?php echo esc_url($current_author->contact_phone_office);?>" title="office_phone"> Office Phone</a></p>

Customize the order of the administration menu

Tested on: WordPress 3.0.1

This code will allow you to reorganize the order of elements in the administration menu. All that you need to do is click on an existing link in the administration menu and copy everything before the /wp-admin/ URL. The order below represents the order the new administration menu will have.

// CUSTOMIZE ADMIN MENU ORDER
function custom_menu_order($menu_ord) {
    if (!$menu_ord)
        return true;
    return array(
     'index.php', // This represents the dashboard link
     'edit.php?post_type=events', // This is a custom post type menu
     'edit.php?post_type=news',
     'edit.php?post_type=articles',
     'edit.php?post_type=faqs',
     'edit.php?post_type=mentors',
     'edit.php?post_type=testimonials',
     'edit.php?post_type=services',
     'edit.php?post_type=page', // This is the default page menu
     'edit.php', // This is the default POST admin menu
 );
}
add_filter('custom_menu_order', 'custom_menu_order');
add_filter('menu_order', 'custom_menu_order');

Function to change the length of Exerpt

Tested on: Wordpress 3.0.1

By default all excerpts are capped at 55 words. Utilizing the code below you can override this default settings:

function new_excerpt_length($length) { 
    return 100;
}

add_filter('excerpt_length', 'new_excerpt_length');

This example changes the excerpt length to 100 words, but you can use the same method to change it to any value.

Add Thumbnails in Manage Posts/Pages List

You can add this to your functions to display to the Manage/Edit Post and Pages List a new column with the thumbnail preview.

/****** Add Thumbnails in Manage Posts/Pages List ******/
if ( !function_exists('AddThumbColumn') && function_exists('add_theme_support') ) {
 
    // for post and page
    add_theme_support('post-thumbnails', array( 'post', 'page' ) );
 
    function AddThumbColumn($cols) {
 
        $cols['thumbnail'] = __('Thumbnail');
 
        return $cols;
    }
 
    function AddThumbValue($column_name, $post_id) {
 
            $width = (int) 35;
            $height = (int) 35;
 
            if ( 'thumbnail' == $column_name ) {
                // thumbnail of WP 2.9
                $thumbnail_id = get_post_meta( $post_id, '_thumbnail_id', true );
                // image from gallery
                $attachments = get_children( array('post_parent' => $post_id, 'post_type' => 'attachment', 'post_mime_type' => 'image') );
                if ($thumbnail_id)
                    $thumb = wp_get_attachment_image( $thumbnail_id, array($width, $height), true );
                elseif ($attachments) {
                    foreach ( $attachments as $attachment_id => $attachment ) {
                        $thumb = wp_get_attachment_image( $attachment_id, array($width, $height), true );
                    }
                }
                    if ( isset($thumb) && $thumb ) {
                        echo $thumb;
                    } else {
                        echo __('None');
                    }
            }
    }
 
    // for posts
    add_filter( 'manage_posts_columns', 'AddThumbColumn' );
    add_action( 'manage_posts_custom_column', 'AddThumbValue', 10, 2 );
 
    // for pages
    add_filter( 'manage_pages_columns', 'AddThumbColumn' );
    add_action( 'manage_pages_custom_column', 'AddThumbValue', 10, 2 );
}

Remove pings to your own blog

Tested on: WordPress 3.0.1

// Remove pings to self
function no_self_ping( &$links ) {
    $home = get_option( 'home' );
    foreach ( $links as $l => $link )
        if ( 0 === strpos( $link, $home ) )
            unset($links[$l]);
}
add_action( 'pre_ping', 'no_self_ping' );

Enable GZIP output compression

Normally the server should be set up to do this automatically, but a lot of shared hosts don’t do this (probably to increase client bandwidth usage).

 if(extension_loaded("zlib") && (ini_get("output_handler") != "ob_gzhandler"))
   add_action('wp', create_function('', '@ob_end_clean();@ini_set("zlib.output_compression", 1);'));

Display DB Queries, Time Spent and Memory Consumption

Tested on: WordPress 3.0.1

function performance( $visible = false ) {

    $stat = sprintf( '%d queries in %.3f seconds, using %.2fMB memory',
            get_num_queries(),
            timer_stop( 0, 3 ),
            memory_get_peak_usage() / 1024 / 1024
        );

    echo $visible ? $stat : "<!-- {$stat} -->" ;
}

Then this code below the code above which will automatically insert the code above into the footer of your public website (make sure your theme is calling wp_footer):

add_action( 'wp_footer', 'performance', 20 );

It can be called multiple times.

Auto Extract the First Image from the Post Content

Tested on: WordPress 3.0.1

This code will automatically extract the first image associated with a post and allow you to display/use it by calling the getImage function.

// AUTOMATICALLY EXTRACT THE FIRST IMAGE FROM THE POST
function getImage($num) {
    global $more;
    $more = 1;
    $link = get_permalink();
    $content = get_the_content();
    $count = substr_count($content, '<img');
    $start = 0;

    for($i=1;$i<=$count;$i++) {
        $imgBeg = strpos($content, '<img', $start);
        $post = substr($content, $imgBeg);
        $imgEnd = strpos($post, '>');
        $postOutput = substr($post, 0, $imgEnd+1);
        $postOutput = preg_replace('/width="([0-9]*)" height="([0-9]*)"/', '',$postOutput);;
        $image[$i] = $postOutput;
        $start=$imgEnd+1;
    }

    if(stristr($image[$num],'<img')) {
        echo '<a href="'.$link.'">'.$image[$num]."</a>";
    }
    $more = 0;
}

Unregister WordPress Default Widgets

Tested on: WordPress 3.0.1

// Unregister all default WordPress Widgets
function unregister_default_wp_widgets() {
    unregister_widget('WP_Widget_Pages');
    unregister_widget('WP_Widget_Calendar');
    unregister_widget('WP_Widget_Archives');
    unregister_widget('WP_Widget_Links');
    unregister_widget('WP_Widget_Meta');
    unregister_widget('WP_Widget_Search');
    unregister_widget('WP_Widget_Text');
    unregister_widget('WP_Widget_Categories');
    unregister_widget('WP_Widget_Recent_Posts');
    unregister_widget('WP_Widget_Recent_Comments');
    unregister_widget('WP_Widget_RSS');
    unregister_widget('WP_Widget_Tag_Cloud');
}
add_action('widgets_init', 'unregister_default_wp_widgets', 1);

Output which theme template file a post/page is using in the header

add_action('wp_head', 'show_template');
function show_template() {
    global $template;
    print_r($template);
}

Shorten the default DIV output if your theme is using post_class.

If your theme is using something like

<div id="post-<?php the_ID(); ?>" <?php post_class(); ?>>

You can have crazy long divs in your source that might look like this or even longer:

<div id="post-4" class="post-4 post type-post hentry category-uncategorized category-test category-test-1-billion category-test2 category-test3 category-testing">

This can really start to clutter your source and seem rather unnecessary in most cases, going 3-4 deep is good enough.

For the top example we can slice the output like so:

// Slice crazy long div outputs
function category_id_class($classes) {
    global $post;
    foreach((get_the_category($post->ID)) as $category)
        $classes[] = $category->category_nicename;
        return array_slice($classes, 0,5);
}
add_filter('post_class', 'category_id_class');

This slices the output to only include the first 5 values, so the above example becomes:

<div id="post-4" class="post-4 post type-post hentry category-uncategorized">

Make category archives display all posts, regardless of post type: good for custom post types

function any_ptype_on_cat($request) {

    if ( isset($request['category_name']) )
        $request['post_type'] = 'any';

    return $request;
}
add_filter('request', 'any_ptype_on_cat');

Remove unwanted dashboard items

This was already posted but it did not have the full list of items. Especially those annoying "incoming links!"

add_action('wp_dashboard_setup', 'my_custom_dashboard_widgets');

function my_custom_dashboard_widgets() {
    global $wp_meta_boxes;

    // Right Now - Comments, Posts, Pages at a glance
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_right_now']);

    // Recent Comments
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_recent_comments']);

    // Incoming Links
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']);

    // Plugins - Popular, New and Recently updated Wordpress Plugins
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']);

    // WordPress Development Blog Feed
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']);

    // Other WordPress News Feed
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary']);

    // Quick Press Form
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']);

    // Recent Drafts List
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_recent_drafts']);
}

Remove "Read More" page jumps**

Instead return to the top of the page. You know how when you click "read more" it will jump to the spot in the page which can be annoying, this makes it just load the page normally, no jumping!

function remove_more_jump_link($link) {
    $offset = strpos($link, '#more-');
    if ($offset) {
        $end = strpos($link, '"', $offset);
    }
    if ($end) {
        $link = substr_replace($link, '', $offset, $end-$offset);
    }
    return $link;
}
add_filter('the_content_more_link', 'remove_more_jump_link');

Restrict ADMIN menu items based on username, replace username with an actual user's name.

function remove_menus()
{
    global $menu;
    global $current_user;
    get_currentuserinfo();

    if($current_user->user_login == 'username')
    {
        $restricted = array(__('Posts'),
                            __('Media'),
                            __('Links'),
                            __('Pages'),
                            __('Comments'),
                            __('Appearance'),
                            __('Plugins'),
                            __('Users'),
                            __('Tools'),
                            __('Settings')
        );
        end ($menu);
        while (prev($menu)) {
            $value = explode(' ',$menu[key($menu)][0]);
            if(in_array($value[0] != NULL ? $value[0] : "" , $restricted)) {
                unset($menu[key($menu)]);
            }
        } // end while

    } // end if
}
add_action('admin_menu', 'remove_menus');

//alternatively you can use if($current_user->user_login != 'admin') instead, probably more useful

Style the tag cloud

// Tag cloud custom
add_filter('widget_tag_cloud_args', 'style_tags');
function style_tags($args) {
    $args = array(
         'largest'    => '10',
         'smallest'   => '10',
         'format'     => 'list',
         );
    return $args;
}

A full reference of options are here (there are a lot!) http://codex.wordpress.org/Function_Reference/wp_tag_cloud

Change Default RSS Widget update timer

(The default is 6 or 12 hours - I forget (1800 = 30 minutes).

add_filter( 'wp_feed_cache_transient_lifetime', create_function('$fixrss', 'return 1800;') );

Remove Plugin Update Notice ONLY for INACTIVE plugins

function update_active_plugins($value = '') {
    /*
    The $value array passed in contains the list of plugins with time
    marks when the last time the groups was checked for version match
    The $value->reponse node contains an array of the items that are
    out of date. This response node is use by the 'Plugins' menu
    for example to indicate there are updates. Also on the actual
    plugins listing to provide the yellow box below a given plugin
    to indicate action is needed by the user.
    */
    if ((isset($value->response)) && (count($value->response))) {

        // Get the list cut current active plugins
        $active_plugins = get_option('active_plugins');    
        if ($active_plugins) {
           
            //  Here we start to compare the $value->response
            //  items checking each against the active plugins list.
            foreach($value->response as $plugin_idx => $plugin_item) {

                // If the response item is not an active plugin then remove it.
                // This will prevent WordPress from indicating the plugin needs update actions.
                if (!in_array($plugin_idx, $active_plugins))
                    unset($value->response[$plugin_idx]);
            }
        }
        else {
             // If no active plugins then ignore the inactive out of date ones.
            foreach($value->response as $plugin_idx => $plugin_item) {
                unset($value->response);
            }          
        }
    }  
    return $value;
}
add_filter('transient_update_plugins', 'update_active_plugins');    // Hook for 2.8.+
//add_filter( 'option_update_plugins', 'update_active_plugins');    // Hook for 2.7.x

Remove superfluous info and HTML within the <head> tag

// remove unnecessary header info
add_action( 'init', 'remove_header_info' );
function remove_header_info() {
    remove_action( 'wp_head', 'rsd_link' );
    remove_action( 'wp_head', 'wlwmanifest_link' );
    remove_action( 'wp_head', 'wp_generator' );
    remove_action( 'wp_head', 'start_post_rel_link' );
    remove_action( 'wp_head', 'index_rel_link' );
    remove_action( 'wp_head', 'adjacent_posts_rel_link' );         // for WordPress < 3.0
    remove_action( 'wp_head', 'adjacent_posts_rel_link_wp_head' ); // for WordPress >= 3.0
}

// remove extra CSS that 'Recent Comments' widget injects
add_action( 'widgets_init', 'remove_recent_comments_style' );
function remove_recent_comments_style() {
    global $wp_widget_factory;
    remove_action( 'wp_head', array(
        $wp_widget_factory->widgets['WP_Widget_Recent_Comments'],
        'recent_comments_style'
    ) );
}

Enable Error Debugging And Logging To Use On Live Sites

This is a piece of code I wrote to make use of the WP_DEBUG constants that are normally disabled by default. Well, I created a way to not only enable WP_DEBUG so you can use it on a live site with no negative side-effects, but I also made use of the other debugging constants for forcing errors to be displayed, and for creating a log file of the errors and Notices in the /wp-content directory.

Drop this code in your wp-config.php file (AFTER YOU SAVE A BACKUP JUST IN CASE) and then you can pass the ?debug=1, 2, or 3 parameters at the end of any URL on your site.

?debug=1 = shows all errors/notices ?debug=2 = forces them to be displayed ?debug=3 = creates a debug.log file of all errors in /wp-content dir.

/**
* Written by Jared Williams - http://new2wp.com
* @wp-config.php replace WP_DEBUG constant with this code
* Enable WP debugging for usage on a live site
* http://core.trac.wordpress.org/browser/trunk/wp-includes/load.php#L230
* Pass the '?debug=#' parameter at the end of any URL on site
*
* http://example.com/?debug=1, /?debug=2, /?debug=3
*/
if ( isset($_GET['debug']) && $_GET['debug'] == '1' ) {
    // Enable the reporting of notices during development - E_ALL
    define('WP_DEBUG', true);
} elseif ( isset($_GET['debug']) && $_GET['debug'] == '2' ) {
    // Must be true for WP_DEBUG_DISPLAY to work
    define('WP_DEBUG', true);
    // Force the display of errors
    define('WP_DEBUG_DISPLAY', true);
} elseif ( isset($_GET['debug']) && $_GET['debug'] == '3' ) {
    // Must be true for WP_DEBUG_LOG to work
    define('WP_DEBUG', true);
    // Log errors to debug.log in the wp-content directory
    define('WP_DEBUG_LOG', true);
}

I go into more detail on the guest post I wrote for Comluv if you're interested, here: http://comluv.com/dev/enable-debugging-and-logging-for-live-site-usage/

I'm still working on a way to make this either password protected, or preferrably somehow make it work on if (current_user_can('manage_themes') and is_logged_in().

But that's where it gets alot more tricky.

Automatically Add Dynamic Titles to Public Pages

Tested on: WordPress 3.0.1

Utilizing the code below will automatically create dynamic page titles based upon the pages/posts being viewed publicly.

/* Dynamic Titles **/
// This sets your <title> depending on what page you're on, for better formatting and for SEO
// You need to set the variable $longd to some custom text at the beginning of the function
function dynamictitles() {
    $longd = __('Enter your longdescription here.', 'texdomainstring');
        if ( is_single() ) {
          wp_title('');
          echo ' | '.get_bloginfo('name');

    } else if ( is_page() || is_paged() ) {
          bloginfo('name');
          wp_title('|');

    } else if ( is_author() ) {
          bloginfo('name');
          wp_title(' | '.__('Author', 'texdomainstring'));

    } else if ( is_category() ) {
          bloginfo('name');
          wp_title(' | '.__('Archive for', 'texdomainstring'));

    } else if ( is_tag() ) {
          echo get_bloginfo('name').' | '.__('Tag archive for', 'texdomainstring');
          wp_title('');

    } else if ( is_archive() ) {
          echo get_bloginfo('name').' | '.__('Archive for', 'texdomainstring');
          wp_title('');

    } else if ( is_search() ) {
          echo get_bloginfo('name').' | '.__('Search Results', 'texdomainstring');
    } else if ( is_404() ) {
          echo get_bloginfo('name').' | '.__('404 Error (Page Not Found)', 'texdomainstring');

    } else if ( is_home() ) {
          echo get_bloginfo('name').' | '.get_bloginfo('description');

    } else {
          echo get_bloginfo('name').' | '.($blog_longd);
    }
}

New Roles and Capabilities - Only run once!

I keep these handy, this is the right way to do them without a plugin. They set a single field (prefix_user_roles) in the options database, and you don't need a plugin to set them. Refer to the Codex page for a list of what capabilities are available and descriptions for what they do. ^[1] You only need to uncomment one of these blocks, load any page and then comment them again! Here I'm creating a role that's got the capabilities I need:

/* Capabilities */

// To add the new role, using 'international' as the short name and
// 'International Blogger' as the displayed name in the User list and edit page:
/*
add_role('international', 'International Blogger', array(
    'read' => true, // True allows that capability, False specifically removes it.
    'edit_posts' => true,
    'delete_posts' => true,
    'edit_published_posts' => true,
    'publish_posts' => true,
    'edit_files' => true,
    'import' => true,
    'upload_files' => true //last in array needs no comma!
));
*/


// To remove one outright or remove one of the defaults:
/* 
remove_role('international');
*/

It's sometimes handy to add/remove from an existing role rather than removing and re-adding one. Again, you only need to uncomment it, reload a page and then comment it again. This will store the role/capability properly in the options table. (This allows you, the developer to control them and removes the overhead of the bulky plugins that do the same thing.) Here I'm changing the author role to delete their published posts (the default), but allowing them the capability to edit their published posts (which isn't possible for this role by default)-- using *add_cap* or *remove_cap*.

/*
$edit_role = get_role('author');
   $edit_role->add_cap('edit_published_posts');
   $edit_role->remove_cap('delete_published_posts');
*/

I keep a spreadsheet with the grid from the Codex page for sites that modify this way, so I can remember how things are set, though leaving the commented out code in your functions.php file will work to. Don't leave these examples uncommented, or it will write to the database with each page load!

Enable shortcodes in widgets

// shortcode in widgets
if ( !is_admin() ){
    add_filter('widget_text', 'do_shortcode', 11);
}

Wordpress Custom Admin Footer

// customize admin footer text
function custom_admin_footer() {
        echo 'add your custom footer text and html here';
} 
add_filter('admin_footer_text', 'custom_admin_footer');

I use this for client sites as a simple point of reference to contact me as the dev.

Function to Disable RSS Feeds

Tested on: Wordpress 3.0.1

You can disable RSS feeds If you want to maintain your Wordpress based website as static.

You can Use this function :

function fb_disable_feed() {
wp_die( __('No feed available,please visit our <a href="'. get_bloginfo('url') .'">homepage</a>!') );
}

add_action('do_feed', 'fb_disable_feed', 1);
add_action('do_feed_rdf', 'fb_disable_feed', 1);
add_action('do_feed_rss', 'fb_disable_feed', 1);
add_action('do_feed_rss2', 'fb_disable_feed', 1);
add_action('do_feed_atom', 'fb_disable_feed', 1);

Change the "Howdy" message to "Welcome"

With this function you can customize the "Howdy" message in top right of your admin area.
This function make use of JQuery to change the "Howdy" message to "Welcome".

/****** Customize admin message "Howdy" to "Welcome" ******/
$nohowdy = "Welcome";

if (is_admin()) {
    add_action('init', 'artdev_nohowdy_h');
    add_action('admin_footer', 'artdev_nohowdy_f');
}
// Load jQuery
function artdev_nohowdy_h() {
    wp_enqueue_script('jquery');
}
// Modify
function artdev_nohowdy_f() {
global $nohowdy;
echo <<<JS
<script type="text/javascript">
//<![CDATA[
var nohowdy = "$nohowdy";
jQuery('#user_info p')
    .html(
    jQuery('#user_info p')
        .html()
        .replace(/Howdy/,nohowdy)
    );
//]]>
JS;
}

PHP version, using gettext filter:

add_filter('gettext', 'change_howdy', 10, 3);

function change_howdy($translated, $text, $domain) {

    if (!is_admin() || 'default' != $domain)
        return $translated;

    if (false !== strpos($translated, 'Howdy'))
        return str_replace('Howdy', 'Welcome', $translated);

    return $translated;
}

Include custom post types in "Right Now" admin dashboard

This will include your custom post types and the post counts for each type in the "Right Now" dashboard widget.

// ADD CUSTOM POST TYPES TO THE 'RIGHT NOW' DASHBOARD WIDGET
function wph_right_now_content_table_end() {
 $args = array(
  'public' => true ,
  'show_ui' => true ,
  '_builtin' => false
 );
 $output = 'object';
 $operator = 'and';
 
 $post_types = get_post_types( $args , $output , $operator );
 foreach( $post_types as $post_type ) {
  $num_posts = wp_count_posts( $post_type->name );
  $num = number_format_i18n( $num_posts->publish );
  $text = _n( $post_type->labels->singular_name, $post_type->labels->name , intval( $num_posts->publish ) );
  if ( current_user_can( 'edit_posts' ) ) {
   $num = "<a href='edit.php?post_type=$post_type->name'>$num</a>";
   $text = "<a href='edit.php?post_type=$post_type->name'>$text</a>";
  }
  echo '<tr><td class="first b b-' . $post_type->name . '">' . $num . '</td>';
  echo '<td class="t ' . $post_type->name . '">' . $text . '</td></tr>';
 }
 $taxonomies = get_taxonomies( $args , $output , $operator ); 
 foreach( $taxonomies as $taxonomy ) {
  $num_terms  = wp_count_terms( $taxonomy->name );
  $num = number_format_i18n( $num_terms );
  $text = _n( $taxonomy->labels->singular_name, $taxonomy->labels->name , intval( $num_terms ));
  if ( current_user_can( 'manage_categories' ) ) {
   $num = "<a href='edit-tags.php?taxonomy=$taxonomy->name'>$num</a>";
   $text = "<a href='edit-tags.php?taxonomy=$taxonomy->name'>$text</a>";
  }
  echo '<tr><td class="first b b-' . $taxonomy->name . '">' . $num . '</td>';
  echo '<td class="t ' . $taxonomy->name . '">' . $text . '</td></tr>';
 }
}
add_action( 'right_now_content_table_end' , 'wph_right_now_content_table_end' );

Add a codex search form to the dashboard header

This is a simple way to add a codex search form to the dashboard header, on the top-right next to the quicklinks drop-down.

/**
 * ADD WP CODEX SEARCH FORM TO DASHBOARD HEADER
 */
function wp_codex_search_form() {
    echo '<form target="_blank" method="get" action="http://wordpress.org/search/do-search.php" class="alignright" style="margin: 11px 5px 0;">
        <input type="text" onblur="this.value=(this.value==\'\') ? \'Search the Codex\' : this.value;" onfocus="this.value=(this.value==\'Search the Codex\') ? \'\' : this.value;" maxlength="150" value="Search the Codex" name="search" class="text"> <input type="submit" value="Go" class="button" />
    </form>';
}

if( current_user_can( 'manage_plugins' )) {
// The number 11 needs to be a 10 for this to work!
    add_filter( 'in_admin_header', 'wp_codex_search_form', 11 );
}

New Media Library Column to Re-Attach Images

This code adds a new column to the Media Library Page allowing you to re-attach images

add_filter("manage_upload_columns", 'upload_columns');
add_action("manage_media_custom_column", 'media_custom_columns', 0, 2);

function upload_columns($columns) {
    unset($columns['parent']);
    $columns['better_parent'] = "Parent";
    return $columns;
}
function media_custom_columns($column_name, $id) {
    $post = get_post($id);
    if($column_name != 'better_parent')
        return;
        if ( $post->post_parent > 0 ) {
            if ( get_post($post->post_parent) ) {
                $title =_draft_or_post_title($post->post_parent);
            }
            ?>
            <strong><a href="<?php echo get_edit_post_link( $post->post_parent ); ?>"><?php echo $title ?></a></strong>, <?php echo get_the_time(__('Y/m/d')); ?>
            <br />
            <a class="hide-if-no-js" onclick="findPosts.open('media[]','<?php echo $post->ID ?>');return false;" href="#the-list"><?php _e('Re-Attach'); ?></a>
            <?php
        } else {
            ?>
            <?php _e('(Unattached)'); ?><br />
            <a class="hide-if-no-js" onclick="findPosts.open('media[]','<?php echo $post->ID ?>');return false;" href="#the-list"><?php _e('Attach'); ?></a>
            <?php
        }
}

Themed custom loop using shortcodes

Arguments are the same as the ones from query_posts ^[1]. The content wrapped between the query tag is the template.

add_shortcode('query', 'shortcode_query');

function shortcode_query($atts, $content){
  extract(shortcode_atts(array( // a few default values
   'posts_per_page' => '10',
   'caller_get_posts' => 1,
   'post__not_in' => get_option('sticky_posts'),
  ), $atts));

  global $post;

  $posts = new WP_Query($atts);
  $output = '';
  if ($posts->have_posts())
    while ($posts->have_posts()):
      $posts->the_post();

      // these arguments will be available from inside $content
      $parameters = array(
        'PERMALINK' => get_permalink(),
        'TITLE' => get_the_title(),
        'CONTENT' => get_the_content(),
        'COMMENT_COUNT' => $post->comment_count,
        'CATEGORIES' => get_the_category_list(', '),
        // add here more...
      );

      $finds = $replaces = array();
      foreach($parameters as $find => $replace):
        $finds[] = '{'.$find.'}';
        $replaces[] = $replace;
      endforeach;
      $output .= str_replace($finds, $replaces, $content);

    endwhile;
  else
    return; // no posts found

  wp_reset_query();
  return html_entity_decode($output);
}

Usage:

[query post_type=page posts_per_page=5]
Listing some pages:    
<h5>{TITLE}</h5>
<div>{CONTENT}</div>
<p><a href="{PERMALINK}">{COMMENT_COUNT} comments</a></p>
[/query]

(will make a query for 5 pages)

Inserting pre-configured widgets anywhere using shortcodes

(some ideas from http://webdesign.anmari.com/shortcode-any-widget)

add_action('widgets_init', 'create_arbitrary_sidebar');
function create_arbitrary_sidebar(){
  register_sidebar(array(
    'name' => __('Arbitrary Widgets'),
    'id' => 'arbitrary',
    'description' => sprintf(__('Widgets from this area can added into posts/pages using the %1$s or %2$s shortcodes.'), '[widget ID]', '[widget Name]'),
    'before_widget' => '<div class="block"><div class="block-content block-%2$s clear-block" id="instance-%1$s">',
    'after_widget' => '</div></div>',
    'before_title' => '<h3 class="title">',
    'after_title' => '</h3>'
   ));
}

add_action('in_widget_form', 'widget_shortcodes_info', 10, 3);
function widget_shortcodes_info($widget, $return, $instance){
  if(!is_numeric($widget->number)) return; // wp-save bug :( widget needs to be saved first...

  global $wp_registered_widgets;

  // get the active widgets from all sidebars
  $sidebars_widgets = wp_get_sidebars_widgets();

  // prepare matches
  $matches = array();
  foreach($wp_registered_widgets as $i => $w)
    if($w['name'] == $widget->name) $matches[] = $w['id'];

  // find out the widget position (number)
  $number = 0;
  $is_arbitrary = false;
  if(!empty($sidebars_widgets['arbitrary']))
    foreach($sidebars_widgets['arbitrary'] as $i => $value):
      if(in_array($value, $matches) && !$is_arbitrary) $number = $number +1;
      if($value == $widget->id) $is_arbitrary = true;
    endforeach;

  echo '<div style="background:#eee; padding: 5px;">To include this widget into your posts or pages use one of the following shortcodes: <br />';
  echo '<code>[widget '.substr(md5($widget->id), 0, 8).']</code> <br /> <code>[widget "'.$widget->name.'"'.(($number > 1) ? ' number='.$number : null).']</code></div>';
}

add_shortcode('widget', 'shortcode_widget');
function shortcode_widget($atts){
  global $wp_registered_widgets, $wp_registered_sidebars;
  extract(shortcode_atts(array(
    'number' => false,        // only taken in consideration if the 1st argument is the "Widget Name" (not the hashed ID)
    'title' => true,          // show titles?
    'area' => 'arbitrary'     // sidebar to search
  ), $atts));

  // get 1st parameter (assuming this is the target widget id or name)
  if (!empty($atts[0])) $widget = esc_attr($atts[0]); else return;

  $sidebar = esc_attr($area);
  $number = intval($number);

  $callback = false;
  $possible_matches = array();
  $sidebars_widgets = wp_get_sidebars_widgets();
  if((empty($sidebars_widgets[$sidebar]) || empty($wp_registered_widgets)) && (current_user_can('edit_themes')))
    return "no valid active widgets in {$sidebar}";

  // assuming we get the md5 hashed ID
  foreach ($wp_registered_widgets as $i => $w)
    if ($widget == substr(md5($w['id']), 0, 8)):
      $callback = ($w['callback']);
      $widget = $w['id']; // real widget ID

    // compare widget names as well, and build a array with the possible widget matches array
    // (which is used later if ID match fails)
    elseif($widget == $w['name']):
      $possible_matches[] = $w['id'];

    endif;

  // nothing found, assume it's the "Widget Name".
  if(!$callback):
    $valid_matches = array();
    foreach($sidebars_widgets[$sidebar] as $i => $w)
      foreach($possible_matches as $id) if($id == $w) $valid_matches[] = $w;

    if(!empty($valid_matches)) $widget = $number ? $valid_matches[$number-1] : $widget = $valid_matches[0];
    if($widget && isset($wp_registered_widgets[$widget]['callback'])) $callback = $wp_registered_widgets[$widget]['callback'];
  endif;

  // yey. we found it
  if($callback):
    ob_start();

    $params = array_merge(array(array_merge($wp_registered_sidebars[$sidebar], array('widget_id' => $widget, 'widget_name' => $wp_registered_widgets[$widget]['name']))), (array)$wp_registered_widgets[$widget]['params']);

    $classname_ = '';
    foreach ((array)$wp_registered_widgets[$widget]['classname'] as $cn)
      if (is_string($cn)) $classname_ .= '_'.$cn; elseif (is_object($cn)) $classname_ .= '_'.get_class($cn);
    $classname_ = ltrim($classname_, '_');
    $params[0]['before_widget'] = sprintf($params[0]['before_widget'], $widget, $classname_);
    $params = apply_filters('dynamic_sidebar_params', $params);

    if (is_callable($callback)) call_user_func_array($callback, $params);
    $output = ob_get_clean();

    // remove h3 if title = false
    if(!$title) $output = preg_replace('#<h3 class="title">(.*?)</h3>#', '', $output);
    return $output;
  else:
   return "widget instance not found: ".esc_attr($atts[0]);
  endif;
}

Usage:

Drop a widget in the "arbitrary widgets" sidebar, save it and you'll get the shortcodes :)

Get a custom field value through shortcodes

add_shortcode('field', 'shortcode_field');

function shortcode_field($atts){
  extract(shortcode_atts(array(
   'post_id' => NULL,
  ), $atts));

  if(!isset($atts[0])) return;
  $field = esc_attr($atts[0]);

  global $post;
  $post_id = (NULL === $post_id) ? $post->ID : $post_id;

  return get_post_meta($post_id, $field, true);
}

Usage:

• [field "my_key"]
• [field "my_key" post_id=1]

Get the TinyURL of a link through shortcodes

add_shortcode('tinyurl', 'shortcode_tinyurl'); 

function shortcode_tinyurl($atts){
  extract(shortcode_atts(array(
   'url' => get_permalink(),
   'title' => '',
   'rel' => 'nofollow'
  ), $atts));
  if(!$title) $title = $url;

  if (FALSE === ($cache = get_transient('tinyurl_'+md5($url)))):
    $cache = wp_remote_retrieve_body(wp_remote_get('http://tinyurl.com/api-create.php?url='.$url));

    set_transient('tinyurl_'+md5($url), $cache, 60*60*24); // 1 day cache, could be incresed
  endif;

  return '<a href="'.esc_url($cache).'" rel="'.esc_attr($rel).'">'.esc_attr($title).'</a>';
}

Usage:

• [tinyurl]
• [tinyurl url="http://google.com" title="google"]

Set Editor Defaults to WYSIWYG or HTML

function my_default_editor() {
    $r = 'tinymce'; // html or tinymce
    return $r;
}
add_filter( 'wp_default_editor', 'my_default_editor' );

Here is how to remove the HTML Editor

jQuery(document).ready(function($) {
$("#edButtonHTML").remove();
});

UPDATED here is another way to set the default editor to HTML

add_filter('wp_default_editor', create_function('', 'return "html";'));

Remove Author Metabox/Options & Move to Publish MetaBox

Tested on: Wordpress 3.0.1

One of the things that drive me crazy is a cluttered Wordpress Admin area. One of the elements which I now always setup from the start in my functions.php file is removing the Author MetaBox and Screen Options and then adding the option into the publish metabox. In my opinion this just makes sense and keep things clean. This also respects applicable permissions.

To achieve this goal, just copy and past the following code into your functions.php file.

If you feel there is a better way of doing this please suggest.

NOTE: UPDATED THE CODE TO FIX A CODING ISSUE

// MOVE THE AUTHOR METABOX INTO THE PUBLISH METABOX
add_action( 'admin_menu', 'remove_author_metabox' );
add_action( 'post_submitbox_misc_actions', 'move_author_to_publish_metabox' );
function remove_author_metabox() {
    remove_meta_box( 'authordiv', 'post', 'normal' );
}
function move_author_to_publish_metabox() {
    global $post_ID;
    $post = get_post( $post_ID );
    echo '<div id="author" class="misc-pub-section" style="border-top-style:solid; border-top-width:1px; border-top-color:#EEEEEE; border-bottom-width:0px;">Author: ';
    post_author_meta_box( $post );
    echo '</div>';
}

Quickly Determine Server & Environment Details

If you have multiple servers and multiple environments such as development, QA, and production environments, this can be very useful.

For my systems, environment is determined by the first 3 letters of the hostname, but this could easily be changed to whatever suits your needs.

add_action( 'admin_notices', 'report_environment_status', 3 );

// Report on which server and environment details
function report_environment_status() {
    $server = php_uname('n');
    switch (strtolower(substr($server,0,3))) {
        case 'pXX':
            $msg = "PRODUCTION";
            break;
        case 'qXX':
            $msg = "QA";
            break;
        case 'dXX':
            $msg = "DEVELOPMENT";
            break;
        default :
            $msg = 'UNKNOWN';
    }
    echo "<div id='update-nag'>";
    echo "<b>You are in the $msg environment. (Server: $server)</b>";
    echo "</div>";
}

This has saved me many times from making updates to the wrong environment.

You can also turn this into a plugin and network activate it so all sites get the notification.

Fixed: Remove Default Wordpress Meta Boxes

This was very handy but had some errors

// REMOVE META BOXES FROM DEFAULT POSTS SCREEN
function remove_default_post_screen_metaboxes() {
 remove_meta_box( 'postcustom','post','normal' ); // Custom Fields Metabox
 remove_meta_box( 'postexcerpt','post','normal' ); // Excerpt Metabox
 remove_meta_box( 'commentstatusdiv','post','normal' ); // Comments Metabox
 remove_meta_box( 'trackbacksdiv','post','normal' ); // Talkback Metabox
 remove_meta_box( 'slugdiv','post','normal' ); // Slug Metabox
 remove_meta_box( 'authordiv','post','normal' ); // Author Metabox
}
add_action('admin_menu','remove_default_post_screen_metaboxes');


// REMOVE META BOXES FROM DEFAULT PAGES SCREEN
function remove_default_page_screen_metaboxes() {
 global $post_type;
 remove_meta_box( 'postcustom','page','normal' ); // Custom Fields Metabox
 remove_meta_box( 'postexcerpt','page','normal' ); // Excerpt Metabox
 remove_meta_box( 'commentstatusdiv','page','normal' ); // Comments Metabox
 remove_meta_box('commentsdiv','page','normal'); // Comments
 remove_meta_box( 'trackbacksdiv','page','normal' ); // Talkback Metabox
 remove_meta_box( 'slugdiv','page','normal' ); // Slug Metabox
 remove_meta_box( 'authordiv','page','normal' ); // Author Metabox
}
add_action('admin_menu','remove_default_page_screen_metaboxes');

Extending Auto Logout Period

Tested on: Wordpress 3.0.1

Using the code below you can increase the time cookies are kept and therefor users who are logged in remain logged in longer:

function keep_me_logged_in_for_1_year( $expirein ) {
   return 31556926; // 1 year in seconds
}
add_filter( 'auth_cookie_expiration', 'keep_me_logged_in_for_1_year' );

Add a "Settings" link for plugins on the plugin list page

Set "Settings" link for plugins on plugin-page in WordPress backend, easy to use jump to settings for users (the code is also with an solution for WordPress version smaller 2.9)

// plugin definitions
define( 'FB_BASENAME', plugin_basename( __FILE__ ) );
define( 'FB_BASEFOLDER', plugin_basename( dirname( __FILE__ ) ) );
define( 'FB_FILENAME', str_replace( FB_BASEFOLDER.'/', '', plugin_basename(__FILE__) ) );
function filter_plugin_meta($links, $file) {
  /* create link */
  if ( $file == FB_BASENAME ) {
    array_unshift(
      $links,
      sprintf( '<a href="options-general.php?page=%s">%s</a>', FB_FILENAME, __('Settings') )
    );
  }
  return $links;
}

global $wp_version;
if ( version_compare( $wp_version, '2.7alpha', '>' ) ) {
    add_filter( 'plugin_action_links_' . FB_WM_BASENAME, 'filter_plugin_meta', 10, 2);
} else {
    add_filter( 'plugin_action_links', 'filter_plugin_meta', 10, 2 );
}

Remove Auto Linking of URLs in WordPress Comments

remove_filter('comment_text', 'make_clickable', 9);

Add page template filter to page listing

Tested on: WP 3.1

Adds a page template filter to the page listing, so you can view a list of pages that have a given template attached.

class Page_Template_Filter {
    private $templates = array();
    public function __construct() {
        // If it's not the admin area or the current user can't edit pages let's just bail here
        if( !is_admin() || !current_user_can('edit_pages') )
            return;
        add_action( 'parse_query',           array( $this, 'pt_parse_query' ) );
        add_action( 'restrict_manage_posts', array( $this, 'pt_restrict_manage_posts' ) );
    }
    public function pt_parse_query( $query ) {
        global $pagenow, $post_type;
        if( 'edit.php' != $pagenow )
            return;

        switch( $post_type ) {
            case 'post':

            break;
            case 'page':
                $this->templates = get_page_templates();

                if( empty( $this->templates ) )
                    return;

                if( !$this->is_set_template() )
                    return;

                $meta_group = array( 'key' => '_wp_page_template', 'value' => $this->get_template() );
                set_query_var( 'meta_query', array( $meta_group ) );
            break;
        }
    }
    public function pt_restrict_manage_posts() {
        if( empty( $this->templates ) )
            return;
        $this->template_dropdown();
    }
    private function get_template() {
        if( $this->is_set_template() )
            foreach( $this->templates as $template ) {
                if( $template != $_GET['page_template'] )
                    continue;
                return $template;
            }
        return '';
    }
    private function is_set_template() {
        return (bool) ( isset( $_GET['page_template'] ) && ( in_array( $_GET['page_template'], $this->templates ) ) );
    }
    private function template_dropdown() {
        ?>
        <select name="page_template" id="page_template">
            <option value=""> - no template - </option>
            <?php foreach( $this->templates as $name => $file ): ?>
            <option value="<?php echo $file; ?>"<?php selected( $this->get_template() == $file ); ?>><?php _e( $name ); ?></option>
            <?php endforeach;?>
        </select>
        <?php 
    }
}

add_action('admin_init', 'load_ptf');
function load_ptf() {
    $Page_Template_Filter = new Page_Template_Filter;
}

Requires at least 3.1 to work, though the meta_query could be replaced with the older meta_key and meta_value for 3.0.

Only show posts and media of the logged-in Author & fix the post/media counts on the filter bars.

Tested on: Wordpress 3.4.1

By default, WordPress allows Authors to see the titles of other users posts, unpublished drafts, and all media, even though they cannot be edited.

Use this code to only allow posts and media of the currently logged in Author to be displayed.

Unlike other solutions, this also fixes the post/media count on the filter bars (All|Published|Draft|Pending|Trash; All|Images|Videos|Unattached).

// Show only posts and media related to logged in author
add_action('pre_get_posts', 'query_set_only_author' );
function query_set_only_author( $wp_query ) {
    global $current_user;
    if( is_admin() && !current_user_can('edit_others_posts') ) {
        $wp_query->set( 'author', $current_user->ID );
        add_filter('views_edit-post', 'fix_post_counts');
        add_filter('views_upload', 'fix_media_counts');
    }
}

// Fix post counts
function fix_post_counts($views) {
    global $current_user, $wp_query;
    unset($views['mine']);
    $types = array(
        array( 'status' =>  NULL ),
        array( 'status' => 'publish' ),
        array( 'status' => 'draft' ),
        array( 'status' => 'pending' ),
        array( 'status' => 'trash' )
    );
    foreach( $types as $type ) {
        $query = array(
            'author'      => $current_user->ID,
            'post_type'   => 'post',
            'post_status' => $type['status']
        );
        $result = new WP_Query($query);
        if( $type['status'] == NULL ):
            $class = ($wp_query->query_vars['post_status'] == NULL) ? ' class="current"' : '';
            $views['all'] = sprintf(__('<a href="%s"'. $class .'>All <span class="count">(%d)</span></a>', 'all'),
                admin_url('edit.php?post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'publish' ):
            $class = ($wp_query->query_vars['post_status'] == 'publish') ? ' class="current"' : '';
            $views['publish'] = sprintf(__('<a href="%s"'. $class .'>Published <span class="count">(%d)</span></a>', 'publish'),
                admin_url('edit.php?post_status=publish&post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'draft' ):
            $class = ($wp_query->query_vars['post_status'] == 'draft') ? ' class="current"' : '';
            $views['draft'] = sprintf(__('<a href="%s"'. $class .'>Draft'. ((sizeof($result->posts) > 1) ? "s" : "") .' <span class="count">(%d)</span></a>', 'draft'),
                admin_url('edit.php?post_status=draft&post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'pending' ):
            $class = ($wp_query->query_vars['post_status'] == 'pending') ? ' class="current"' : '';
            $views['pending'] = sprintf(__('<a href="%s"'. $class .'>Pending <span class="count">(%d)</span></a>', 'pending'),
                admin_url('edit.php?post_status=pending&post_type=post'),
                $result->found_posts);
        elseif( $type['status'] == 'trash' ):
            $class = ($wp_query->query_vars['post_status'] == 'trash') ? ' class="current"' : '';
            $views['trash'] = sprintf(__('<a href="%s"'. $class .'>Trash <span class="count">(%d)</span></a>', 'trash'),
                admin_url('edit.php?post_status=trash&post_type=post'),
                $result->found_posts);
        endif;
    }
    return $views;
}

// Fix media counts
function fix_media_counts($views) {
    global $wpdb, $current_user, $post_mime_types, $avail_post_mime_types;
    $views = array();
    $_num_posts = array();
    $count = $wpdb->get_results( "
        SELECT post_mime_type, COUNT( * ) AS num_posts 
        FROM $wpdb->posts 
        WHERE post_type = 'attachment' 
        AND post_author = $current_user->ID 
        AND post_status != 'trash' 
        GROUP BY post_mime_type
    ", ARRAY_A );
    foreach( $count as $row )
        $_num_posts[$row['post_mime_type']] = $row['num_posts'];
    $_total_posts = array_sum($_num_posts);
    $detached = isset( $_REQUEST['detached'] ) || isset( $_REQUEST['find_detached'] );
    if ( !isset( $total_orphans ) )
        $total_orphans = $wpdb->get_var("
            SELECT COUNT( * ) 
            FROM $wpdb->posts 
            WHERE post_type = 'attachment' 
            AND post_author = $current_user->ID 
            AND post_status != 'trash' 
            AND post_parent < 1
        ");
    $matches = wp_match_mime_types(array_keys($post_mime_types), array_keys($_num_posts));
    foreach ( $matches as $type => $reals )
        foreach ( $reals as $real )
            $num_posts[$type] = ( isset( $num_posts[$type] ) ) ? $num_posts[$type] + $_num_posts[$real] : $_num_posts[$real];
    $class = ( empty($_GET['post_mime_type']) && !$detached && !isset($_GET['status']) ) ? ' class="current"' : '';
    $views['all'] = "<a href='upload.php'$class>" . sprintf( __('All <span class="count">(%s)</span>', 'uploaded files' ), number_format_i18n( $_total_posts )) . '</a>';
    foreach ( $post_mime_types as $mime_type => $label ) {
        $class = '';
        if ( !wp_match_mime_types($mime_type, $avail_post_mime_types) )
            continue;
        if ( !empty($_GET['post_mime_type']) && wp_match_mime_types($mime_type, $_GET['post_mime_type']) )
            $class = ' class="current"';
        if ( !empty( $num_posts[$mime_type] ) )
            $views[$mime_type] = "<a href='upload.php?post_mime_type=$mime_type'$class>" . sprintf( translate_nooped_plural( $label[2], $num_posts[$mime_type] ), $num_posts[$mime_type] ) . '</a>';
    }
    $views['detached'] = '<a href="upload.php?detached=1"' . ( $detached ? ' class="current"' : '' ) . '>' . sprintf( __( 'Unattached <span class="count">(%s)</span>', 'detached files' ), $total_orphans ) . '</a>';
    return $views;
}

Remove XML-RPC when not in use for performance boost

Tested on: Wordpress 3.0.1

WordPress uses a CURL operation to test for SSL capability for XML-RPC. If you're using XML-RPC but not using, then you can remove the filter. This is a small performance boost (since basically WP does a cURL GET on the https url and either 1) gets a denied message, or 2) times out, and it can take upwards of 5 seconds), but in our case it actually prevented a gateway timeout where a proxy was timing out before the cURL GET was timing out rendering XML-RPC unusable.

// Prevents WordPress from testing ssl capability on domain.com/xmlrpc.php?rsd
remove_filter('atom_service_url','atom_service_url_filter');

Collection of quick function.php edits

I have a few awesome tweaks in functions.php as well. Found most of these by searching for them over the years.

Excerpt Ending

function new_excerpt_more($more) {
    return '...';
}
add_filter('excerpt_more', 'new_excerpt_more');

Replace WP Admin Logo

function new_admin_logo() {
  echo '<style type="text/css">#header-logo { background-image: url('.get_bloginfo('template_directory').'/images/admin_logo.png) !important; }</style>';
}
add_action('admin_head', 'new_admin_logo');

Custom Favicon WP-Admin

function admin_favicon() {
 echo '<link rel="shortcut icon" type="image/x-icon" href="' . get_bloginfo('template_directory') . '/images/favicon.ico" />';
}
add_action( 'admin_head', 'admin_favicon' );

Custom Admin Footer

function custom_admin_footer() {
echo 'Welcome to my blog! No More Documentation Links!';
}
add_filter('admin_footer_text', 'custom_admin_footer');

Grab all custom fields globally

function get_custom_field($key, $echo = FALSE) {
    global $post;
    $custom_field = get_post_meta( $post->ID, $key, true );
    if ( $echo == false ) 
        return $custom_field;
    echo $custom_field;
}

Then call the field with a single line

<?php get_custom_field('custom-field-name', TRUE); ?>

Return the number of comments

This is like count_user_posts(), but returns the number of comments instead:

function count_user_comments($id) {
global $wpdb;
$users = $wpdb->get_var("
        SELECT COUNT( * ) AS total
        FROM $wpdb->comments
        WHERE comment_approved = 1 
        AND user_id = $id");
return $users;
}

More: Count User's posts (including custom post types) or comments:

function atom_count($user_id, $what_to_count = 'post') {
  global $wpdb;    
  $where = $what_to_count == 'comment' ? "WHERE comment_approved = 1 AND user_id = {$user_id}" : get_posts_by_author_sql($what_to_count, TRUE, $user_id);
  $from = "FROM ".(($what_to_count == 'comment') ? $wpdb->comments : $wpdb->posts);    
  $count = $wpdb->get_var($wpdb->prepare("SELECT COUNT(*) {$from} {$where}"));
  return $count;
}

Usage examples:

<?php echo atom_count(1, 'movie'); // displays 'movie' post type count ?>

<?php echo atom_count(1, 'comment'); // displays comment count ?>

Enable oEmbed in Text/HTML Widgets

add_filter( 'widget_text', array( $wp_embed, 'run_shortcode' ), 8 );
add_filter( 'widget_text', array( $wp_embed, 'autoembed'), 8 );

I use this for youtube video widgets and flickr stuff.

Post Word Count

Tested on: Wordpress 3.0.1

(Originally extracted from the Post Word Count plug-in ^[1] by Nick Momrick ^[2])

Adds a count of total published words to the bottom of the "Right Now" box on the admin dashboard. Useful if you're using your blog as an outlet for something like NaNoWriMo ^[3] or if you just want to keep track of how prolific your blogging skills have become.

function post_word_count() {
    $count = 0;
    $posts = get_posts( array(
        'numberposts' => -1,
        'post_type' => array( 'post', 'page' )
    ));
    foreach( $posts as $post ) {
        $count += str_word_count( strip_tags( get_post_field( 'post_content', $post->ID )));
    }
    $num =  number_format_i18n( $count );
    // This block will add your word count to the stats portion of the Right Now box
    $text = _n( 'Word', 'Words', $num );
    echo "<tr><td class='first b'>{$num}</td><td class='t'>{$text}</td></tr>";
    // This line will add your word count to the bottom of the Right Now box.
    echo '<p>This blog contains a total of <strong>' . $num . '</strong> published words!</p>';
}

// add to Content Stats table
add_action( 'right_now_content_table_end', 'post_word_count');
// add to bottom of Activity Box
add_action('activity_box_end', 'post_word_count');

Kudos to Rarst ^[4] for the query-free cleanup of the code!

Loading scripts conditionally

Here is a way to load scripts only if a particular shortcode or widget is present. source: Loading scripts only if a particular shortcode or widget is present ^[1]

function has_my_shortcode($posts) {
    if ( empty($posts) )
        return $posts;
    $found = false;
    foreach ($posts as $post) {
        if ( stripos($post->post_content, '[my_shortcode') )
            $found = true;
            break;
        }
    if ($found){
        $urljs = get_bloginfo( 'template_directory' ).IMP_JS;
    wp_register_script('my_script', $urljs.'myscript.js' );
    wp_print_scripts('my_script');
}
    return $posts;
}
add_action('the_posts', 'has_my_shortcode');

And here is how to load scripts only if a certain widget is present

To load the script in the page where the widget is loaded only, you will have to add the is_active_widget() code, in you widget class. E.g., see the default recent comments widget (wp-includes/default-widgets.php, line 602):

class WP_Widget_Recent_Comments extends WP_Widget {
    function WP_Widget_Recent_Comments() {
        $widget_ops = array('classname' => 'widget_recent_comments', 'description' => __( 'The most recent comments' ) );
        $this->WP_Widget('recent-comments', __('Recent Comments'), $widget_ops);
        $this->alt_option_name = 'widget_recent_comments';
        if ( is_active_widget(false, false, $this->id_base) )
        add_action( 'wp_head', array(&$this, 'recent_comments_style') );
        add_action( 'comment_post', array(&$this, 'flush_widget_cache') );
        add_action( 'transition_comment_status', array(&$this, 'flush_widget_cache') );
    }

Custom Dashboard CSS

/* Change WordPress dashboard CSS */
function custom_admin_styles() {
    echo '<style type="text/css">#wphead{background:#069}</style>';
}
add_action('admin_head', 'custom_admin_styles');

You can add any changes to the css between the tags.

Remove Private and Protected Prefix

This function removes the "Privite:" prefix from posts and pages marked private. Useful for content only visible to logged in users or groups.

function the_title_trim($title) {
$title = attribute_escape($title);
$findthese = array(
    '#Protected:#',
    '#Private:#'
);
$replacewith = array(
    '', // What to replace "Protected:" with
    '' // What to replace "Private:" with
);
$title = preg_replace($findthese, $replacewith, $title);
return $title;
}
add_filter('the_title', 'the_title_trim');

EDIT: Updated to include the removal of Protected: as well.

Custom excerpt length

function excerpt($num) {
    $limit = $num+1;
    $excerpt = explode(' ', get_the_excerpt(), $limit);
    array_pop($excerpt);
    $excerpt = implode(" ",$excerpt)."... (<a href='" .get_permalink($post->ID) ." '>Read more</a>)";
    echo $excerpt;
}

Limit the length of the displayed excerpt by writing in the theme: excerpt('20');

Example: <?php excerpt('22'); ?> This will limit the excerpt to 22 characters.

The excerpt will be interupted with ... (Read More)

Add parent page slug to body_class

/***************************************************************
* Function body_class_section
* Add the top level page to the body class for coloured sections
***************************************************************/

add_filter('body_class','body_class_section');

function body_class_section($classes) {
    global $wpdb, $post;
    if (is_page()) {
        if ($post->post_parent) {
            $parent  = end(get_post_ancestors($current_page_id));
        } else {
            $parent = $post->ID;
        }
        $post_data = get_post($parent, ARRAY_A);
        $classes[] = 'section-' . $post_data['post_name'];
    }
    return $classes;
}

This filter adds a unique body class based on the highest level parent of the current page. I use this for sites that have specific colours or layouts for each section of the site. It works best with sites based around pages. CSS examples:

.section-about { background: red; }
.section-portfolio { background: blue; }

Your theme must also make use of the body_class function ^[1].

Fix oEmbed flash objects

/***************************************************************
* Function my_oembed_wmode
* Fix oEmbed window mode for flash objects
***************************************************************/

add_filter('embed_oembed_html', 'my_oembed_wmode', 1);

function my_oembed_wmode( $embed ) {
    if ( strpos( $embed, '<param' ) !== false ) {
        $embed = str_replace( '<embed', '<embed wmode="transparent" ', $embed );
        $embed = preg_replace( '/param>/', 'param><param name="wmode" value="transparent" />', $embed, 1);
    }
    return $embed;
}

I have had problems in the past where oEmbed Flash objects collide with drop down navigation menus. This filter fixes that problem by adding a transparent window mode to the embeds.

Remove the "comments" column from Admin page list

/***************************************************************
* Function custom_pages_columns
* Remove "comments" from pages overview (rarely use comments on pages)
***************************************************************/

add_filter('manage_pages_columns', 'custom_pages_columns');

function custom_pages_columns($defaults) {
    unset($defaults['comments']);
    return $defaults;
}

I hardly ever make use of commenting on pages and this helps keep things tidy in the WordPress dashboard.

Enable Numeric Pagination

Tested on: Wordpress 3.0.1

/* Numeric Pagination ********************************************/

function numeric_pagination ($pageCount = 9, $query = null) {

 if ($query == null) {
  global $wp_query;
  $query = $wp_query;
 }

 if ($query->max_num_pages <= 1) {
  return;
 }

 $pageStart = 1;
 $paged = $query->query_vars['paged'];

 // set current page if on the first page
 if ($paged == null) {
  $paged = 1;
 }

 // work out if page start is halfway through the current visible pages and if so move it accordingly
 if ($paged > floor($pageCount / 2)) {
  $pageStart = $paged - floor($pageCount / 2);
 }

 if ($pageStart < 1) {
  $pageStart = 1;
 }

 // make sure page start is
 if ($pageStart + $pageCount > $query->max_num_pages) {
  $pageCount = $query->max_num_pages - $pageStart;
 }

?>
 <div id="archive_pagination">
<?php
 if ($paged != 1) {
?>
 <a href="<?php echo get_pagenum_link(1); ?>" class="numbered page-number-first"><span>&lsaquo; <?php _e('<< First', 'global'); ?></span></a>
<?php
 }
 // first page is not visible...
 if ($pageStart > 1) {
  //echo 'previous';
 }
 for ($p = $pageStart; $p <= $pageStart + $pageCount; $p ++) {
  if ($p == $paged) {
?>
  <span class="numbered page-number-<?php echo $p; ?> current-numeric-page"><?php echo $p; ?></span>
<?php } else { ?>
  <a href="<?php echo get_pagenum_link($p); ?>" class="numbered page-number-<?php echo $p; ?>"><span><?php echo $p; ?></span></a>

<?php
  }
 }
 // last page is not visible
 if ($pageStart + $pageCount < $query->max_num_pages) {
  //echo "last";
 }
 if ($paged != $query->max_num_pages) {
?>
  <a href="<?php echo get_pagenum_link($query->max_num_pages); ?>" class="numbered page-number-last"><span><?php _e('>> Last', 'global'); ?> &rsaquo;</span></a>
<?php } ?>

 </div>

Display Specific Content only for logged in users

Tested on: Wordpress 3.0.1

function content_only4logged_in($content) {

    // ALL LOGGED IN USERS
    if ( is_user_logged_in() &&
            !is_null($content) &&
            !is_feed()
         ) {
        return $content;
    } else {
        $content  = wp_html_excerpt( $content, 80 );
        $content .= ' …';
        $content .= __( 'Sorry, more of this content is only available for logged users.', FB_TEXTDOMAIN );
        return $content;
    }
}
add_action( 'the_content', 'content_only4logged_in' );

more possibilities and informations on the post http://wpengineer.com/2046/control-the-wordpress-content-via-userrights-or-time/

Make your Shortlinks Shorter by Removing WWW

Tested on: Wordpress 3.0.1

Make your shortlinks shorter if you include www. in your domain. Via scratch99.com ^[1]:

add_filter('get_shortlink','sjc_alter_shortlink');
function sjc_alter_shortlink($shortlink) {
    $shortlink = preg_replace('/^(https?:\/\/)?(www\.)/','$1',$shortlink);
    return $shortlink;
}

Check if a post has embedded content.

Check if a post has embedded content, works inside the loop using the current post's ID, or alternatively can be passed an ID to determine the post to check for embedded content.

function has_embed( $post_id = false ) {
    if( !$post_id ) $post_id = get_the_ID();
    else $post_id = absint( $post_id );
    if( !$post_id ) return false;

    $post_meta = get_post_custom_keys( $post_id );
    $post_meta = array_map( 'trim' , $post_meta );

    foreach( $post_meta as $meta ) {
        if( '_oembed' != substr( $meta , 0 , 7 ) )
            continue;
        return true;
    }
    return false;
}

You'd use the function in the same way you check if a post has a tag..

if( has_embed() ) {
   // do whatever
}

Function returns true if an embed is found, false on fail.

Display Posts from Different Custom Post Types on homepage

By dropping the following code on the bottom of this post into your functions.php file you can get wordpress to automatically display posts from different custom post types you have created. Currently by default wordpress only display posts which belong to the default "posts" post type.

In the example provided below you will need to change the section which calls:

$query->set( 'post_type', array('post', 'page', 'services', 'attachment'));

With your own custom post types which you would like to include in the homepage post list results. In this case we are asking wordpress to return to us all posts belonging to the default "post" and "page" post_type then asking wordpress to also include the custom post type we created for "services" and finally the default wordpress post type of "attachment" which just means that anytime something is added to the media library it will automatically get displayed on the homepage as a separate entry.

// CUSTOM HOMEPAGE POST LIST INCLUDING DIFFERENT POST_TYPES
// make sure to edit the post types you wanted included in the list below
add_filter( 'pre_get_posts', 'my_homepage_post_list' );
function my_homepage_post_list ( $query ) {
    if ( is_home() && false == $query->query_vars['suppress_filters'] )
        $query->set( 'post_type', array('post', 'page', 'services', 'attachment'));
    return $query;
}

You can also utilize this custom query in different locations, such as in a custom feed through something like this

if (( is_home() && false == $query->query_vars['suppress_filters'] ) || is_feed())

Remove default fields contact info user profile and replace them with something more usable

The second part of this function has already been mentioned above, but removing the default fields - AIM, Yahoo IM and Jabber/Google Talk - not yet:

function update_contact_methods( $contactmethods ) {

// Remove annoying and unwanted default fields  
unset($contactmethods['aim']);  
unset($contactmethods['jabber']);  
unset($contactmethods['yim']);  

// Add new fields  
$contactmethods['phone'] = 'Phone';  
$contactmethods['mobile'] = 'Mobile';  
$contactmethods['address'] = 'Address';  

return $contactmethods;
}
add_filter('user_contactmethods', 'update_contact_methods');

Of course you can add as many fields as you want (see previous examples earlier in this thread) under "Add new fields"

Pre-populating post types

Here is one for this collection.

////////////////////////////////////////////////////////////////////////////////////
// This auto populates post types and posts.
///////////////////////////////////////////////////////////////////////////////////

add_filter( 'default_content', 'my_editor_content' );

function my_editor_content( $content ) {

    global $post_type;

    switch( $post_type ) {
        case 'your_post_type_here': //auto populate
            $content = 'The content you want to pre-populate the post type with.';
break;
     }

    return $content;
}

This can come in handy for when you need to post the same info over and over again with slight differences.

Auto Include Google Analytics Code

Tested on: Wordpress 3.1 RC3

I've been using this script on all of my sites since WordPress 2.3.0 ... it just adds the standard Google tracking scripts to the footer.

// Add Google Analytics Tracking Code
function add_google_analytics() {
?>
<script type="text/javascript">
    var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
    document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
</script>
<script type="text/javascript">
    try {
        var pageTracker = _gat._getTracker("UA-XXXXXXX-X");
        pageTracker._trackPageview();
    } catch(err) {}</script>
<?php
}

add_action('wp_footer', 'add_google_analytics');

Just be sure to replace UA-XXXXXXX-X with your own Google tracking code...

List all constants for information and debugging

Tested on: Wordpress 3.0.1

Will only display the information if you are a logged in user

if ( is_user_logged_in() ) {
    print('<pre>');
    print_r( @get_defined_constants() );
    print('</pre>');
}

Here is version with optional filter that will partially match constant names and values:

function constants($filter = false) {

        $constants = get_defined_constants();

        if( $filter ) {

            $temp = array();

            foreach ( $constants as $key => $constant )
                if( false !== stripos( $key, $filter ) || false !== stripos( $constant, $filter ) )
                    $temp[$key] = $constant;

            $constants = $temp;
        }

        ksort( $constants );
        var_dump( $constants );
    }

Add auto-update/plugin-installer on you localhost

define ('FS_METHOD', 'direct');

Put this in your wp-config.php.

Change default Author Slug

Put this in your functions to change the default Author Slug to whatever you want,
just change the "sellers" to the slug you want.

// Change URL Slug from Author to Sellers
function new_author_base() {
    global $wp_rewrite;
    $author_slug = 'sellers';
    $wp_rewrite->author_base = $author_slug;
}
add_action('init', 'new_author_base');

Add "Next-page"-button in WYSIYG-editor

add_filter('mce_buttons','wysiwyg_editor');
function wysiwyg_editor($mce_buttons) {
    $pos = array_search('wp_more',$mce_buttons,true);
    if ($pos !== false) {
        $tmp_buttons = array_slice($mce_buttons, 0, $pos+1);
        $tmp_buttons[] = 'wp_page';
        $mce_buttons = array_merge($tmp_buttons, array_slice($mce_buttons, $pos+1));
    }
    return $mce_buttons;
}

Add custom styles to TinyMCE editor

Sometimes users and clients get confused about how their content is displayed in the editor versus how it is displayed on the front-end. Copying just a few relevant lines from your main stylesheet into your new tinymce.css can help a lot:

function custom_mce_css($wp) {
    return $wp .= ',' . get_bloginfo('stylesheet_directory') . '/css/tinymce.css';
}
add_filter( 'mce_css', 'custom_mce_css' );

Resize large image on upload

Image will be resize according to the large size in your media settings.

/**resize on upload to the largest size in media setting */


function replace_uploaded_image($image_data) {
// if there is no large image : return
if (!isset($image_data['sizes']['large'])) return $image_data;

// path to the uploaded image and the large image
$upload_dir = wp_upload_dir();
$uploaded_image_location = $upload_dir['basedir'] . '/' .$image_data['file'];
$large_image_location = $upload_dir['path'] . '/'.$image_data['sizes']['large']['file'];

// delete the uploaded image
unlink($uploaded_image_location);

// rename the large image
rename($large_image_location,$uploaded_image_location);

// update image metadata and return them
$image_data['width'] = $image_data['sizes']['large']['width'];
$image_data['height'] = $image_data['sizes']['large']['height'];
unset($image_data['sizes']['large']);

return $image_data;
}
add_filter('wp_generate_attachment_metadata','replace_uploaded_image');

Use figure and figcaption for captions

Tested on: WordPress 3.1.3

(Credits to WP Engineer: http://wpengineer.com/917/filter-caption-shortcode-in-wordpress/)

function mytheme_caption( $attr, $content = null ) {
    $output = apply_filters( 'img_caption_shortcode', '', $attr, $content );
    if ( $output != '' )
        return $output;

    extract( shortcode_atts ( array(
    'id' => '',
    'align' => 'alignnone',
    'width'=> '',
    'caption' => ''
    ), $attr ) );

    if ( 1 > (int) $width || empty( $caption ) )
        return $content;

    if ( $id ) $id = 'id="' . $id . '" ';

    return '<figure ' . $id . 'class="wp-caption ' . $align . '" style="width: ' . $width . 'px">'
. do_shortcode( $content ) . '<figcaption class="wp-caption-text">' . $caption . '</figcaption></figure>';
}

add_shortcode( 'wp_caption', 'mytheme_caption' );
add_shortcode( 'caption', 'mytheme_caption' );

Here are some nice shortcodes for you to use:

1. Easy-to-add Twitter and Facebook share button shortcode

function shreplz() {
   return '
    <div class="sharebox">
    <div class="twittme"><a href="https://twitter.com/share" class="twitter-share-button" data-count="horizontal">Tweet</a><script type="text/javascript" src="//platform.twitter.com/widgets.js"></script></div>
    <div class="shareface"><a name="fb_share"></a> <script src="http://static.ak.fbcdn.net/connect.php/js/FB.Share" type="text/javascript"></script></div>
    <br style="clear: left;" />
    </div>
   ';
}
add_shortcode('sharethis', 'shreplz');
// How to use: [sharethis]

2. Easy remote site snapshot using WordPress API shortcode

function wpr_snap($atts, $content = null) {
        extract(shortcode_atts(array(
            "snap" => 'http://s.wordpress.com/mshots/v1/',
            "url" => 'http://www.sagive.co.il',
            "alt" => 'My image',
            "w" => '400', // width
            "h" => '300' // height
        ), $atts));

    $img = '<img src="' . $snap . '' . urlencode($url) . '?w=' . $w . '&h=' . $h . '" alt="' . $alt . '"/>';
        return $img;
}

add_shortcode("snap", "wpr_snap");
// How to use: [snap url="http://www.example.com" alt="Cool Site!" w="300px" h="200px"]

3. Easy to use & embed iFrame shortcode

function GenerateIframe( $atts ) {
    extract( shortcode_atts( array(
        'href' => 'http://the-url',
        'height' => '550px',
        'width' => '600px',
    ), $atts ) );

    return '<iframe src="'.$href.'" width="'.$width.'" height="'.$height.'"> <p>Your Browser does not support Iframes.</p></iframe>';
}
add_shortcode('iframe', 'GenerateIframe');
// How to use: [iframe href="http://www.exmaple.com" height="480" width="640"]

4. Easy-to-include remote file / doc with shortcode

function getfile_content( $atts ) {
  extract( shortcode_atts( array(
    'fileurl' => ''
  ), $atts ) );

  if ($fileurl!='')
    return @file_get_contents($fileurl);
}

add_shortcode( 'getfile', 'getfile_content' );
// How to use: [getfile fileurl="http://www.exmaple.com/somepage.html"]

. Here are some comments related snippets:

1. Close the ability to comment globally

function closeCommentsGlobaly($data) { return false; }
add_filter('comments_number', 'closeCommentsGlobaly');
add_filter('comments_open', 'closeCommentsGlobaly');

2. Give the administrator a different CSS class for the administrator's comments

if (1 == $comment->user_id)
    echo 'siteadmin'; // Pick your class here

3. A really cool rich with a data list of comments - gr8 for custom locked page

$comments = get_comments( array(
    'number'    => 10, // How many comments
    'status'    => 'approve' // Type of comments
) );

foreach($comments as $eachComment){

    // Collect the data and assign it
    $commentID = comment_ID;
    $commentAuthorEmail = $eachComment->comment_author_email;
    $commentPostId = $eachComment->comment_post_ID;
    $commentPostTitle = get_the_title( $commentPostId );
    $commentPostUrl = get_permalink( $commentPostId );
    $comment_sidebarnumber = get_comments_number( $commentPostId );

    global $wpdb;
    $userCommentCount = $wpdb->get_var('SELECT COUNT('.$commentID.') FROM ' . $wpdb->comments. ' WHERE comment_author_email = "' . $commentAuthorEmail . '"');

    echo '<div style="border: 1px solid #ccc; padding: 10px;">';
    echo '<ul style="margin: 0px;">';
    echo '<li>Name: '. $eachComment->comment_author .'</li>';
    echo '<li>Commented about: <a href="'.$commentPostUrl.'">'. $commentPostTitle .'</a></li>';
    echo '<li>Commented On: '. $eachComment->comment_date .'</li>';
    echo '<li>Commneter Site: '. $eachComment->comment_author_email .'</</li>';
    echo '<li>Commenter Email: '. $eachComment->comment_author_email .'</</li>';
    echo '<li>This Commenter'. $eachComment->comment_author .' Commented '. $userCommentCount .' on your site</</li>';
    echo '</ul>';
    echo '<p style="padding: 10px;"><strong>'. $eachComment->comment_author .' wrote</strong>: '. $eachComment->comment_content .'</p>';
    echo '</div>';
}

Conditional to check for hierarchy descendant

A conditional function to check if the current page is a descendant of the ID given to it. Useful for determining if a page is a grandchild, great-grandchild or father down the hierarchy tree.

function is_tree($pid) {      // $pid = The ID of the page we're looking for pages underneath
    global $post;         // load details about this page

    $anc = get_post_ancestors( $post->ID );
    foreach($anc as $ancestor) {
        if(is_page() && $ancestor == $pid) {
            return true;
        }
    }
    if(is_page()&&(is_page($pid))) 
               return true;   // we're at the page or at a sub page
    else 
               return false;  // we're elsewhere
};

Create a conditional tag for custom taxonomies

In this example, 'student' was a custom post type, and 'stud_cat' was the custom taxonomy. Use has_student(null) for the conditional

    function has_student( $student, $_post = null ) {
    if ( !empty( $student ) )
        return false;
    if ( $_post )
        $_post = get_post( $_post );
    else
        $_post =& $GLOBALS['post'];
    if ( !$_post )
        return false;
    $r = is_object_in_term( $_post->ID, 'studcat', $student );
    if ( is_wp_error( $r ) )
        return false;
    return $r;
}

Easy WordPress Security Fixes

Security through obscurity is the name of the game here. These functions do three different things.

1. Remove the version string from the code. No point in telling folks what version we're running.
2. Removes any error messages (Wrong Password, No Such User, etc.) from admin login screens

3. When the admin posts a comment, a CSS class is added. This removes the admin name in comments.

   //REMOVE VERSION STRING FROM HEADER
   remove_action('wp_head', 'wp_generator');
   
   //HIDE LOGIN ERROR MESSAGES (Wrong Password, No Such User etc.)
   add_filter('login_errors',create_function('$a', "return null;"));
   
   // Remove admin name in comments class
   // Source: http://www.wprecipes.com/wordpress-hack-remove-admin-name-in-comments-class
   function remove_comment_author_class( $classes ) {
       foreach( $classes as $key => $class ) {
           if(strstr($class, "comment-author-")) {
               unset( $classes[$key] );
           }
       }
       return $classes;
   }
   add_filter( 'comment_class' , 'remove_comment_author_class' );
   

Replace Default Gravatar with Custom Image

All you'll need to customize is the path to your default image.

function custom_gravatar($avatar_defaults) {
    $logo = get_bloginfo('template_directory') . '/images/icons/gravatar_logo.jpg'; //Change to whatever path you like.
    $avatar_defaults[$logo] = get_bloginfo('name');
    return $avatar_defaults;
}//END FUNCTION    
add_filter( 'avatar_defaults', 'custom_gravatar' );

Automatically create a new page upon activating a theme

if (isset($_GET['activated']) && is_admin()){
    $new_page_title = 'This is the page title';
    $new_page_content = 'This is the page content';
    $new_page_template = ''; //ex. template-custom.php. Leave blank if you don't want a custom page template.

//don't edit under this line
$page_check = get_page_by_title($new_page_title);
$new_page = array(
    'post_type' => 'page',
    'post_title' => $new_page_title,
    'post_content' => $new_page_content,
    'post_status' => 'publish',
    'post_author' => 1,
);
if(!isset($page_check->ID)){
    $new_page_id = wp_insert_post($new_page);
    if(!empty($new_page_template)){
        update_post_meta($new_page_id,'_wp_page_template', $new_page_template);
    }
}

List all SubCategories

Tested on: Wordpress 3.0.1

$echo = '<ul>' . "\n";
$childcats = get_categories('child_of=' . $cat . '&hide_empty=1');
foreach ($childcats as $childcat) {
    if (1 == $childcat->category_parent) {
        $echo .= "\t" . '<li><a href="' . get_category_link($childcat->cat_ID).'" title="' . $childcat->category_description . '">';
        $echo .= $childcat->cat_name . '</a>';
        $echo .= '</li>' . "\n";
    }
}
$echo .= '</ul>' . "\n";
echo $echo;

also here, more informations and functins in the post http://wpengineer.com/2025/list-all-subcategories/

Auto Clean SEO Slugs without removing functionality

Tested on: Wordpress 3.0.1

By adding this code to your functions.php file wordpress will automatically clean up the slug URL title by removing all unnecessary words. I have also extended the capabilities with additional customizations which hide the screen option for slug as well as the metabox. By including the code below any new post you create will automatically get shortened and you will still have the ability to manually edit the slug by clicking on the url under the post title and saving the post.

// AUTOMATICALLY SANITIZE PAGE/POST SEO SLUG FROM SHORT WORDS
   add_filter('name_save_pre', 'seo_slugs', 0);
   function seo_slugs($slug) {
    // We don't want to change an existing slug
 if ($slug) return $slug;
 global $wpdb;
 $seo_slug = strtolower(stripslashes($_POST['post_title']));
 $seo_slug = preg_replace('/&.+?;/', '', $seo_slug); // kill HTML entities
    // kill anything that is not a letter, digit, space or apostrophe
 $seo_slug = preg_replace ("/[^a-zA-Z0-9 \']/", "", $seo_slug);
    // Turn it to an array and strip common words by comparing against c.w. array
 $seo_slug_array = array_diff (split(" ", $seo_slug), seo_slugs_stop_words());
    // Turn the sanitized array into a string
 $seo_slug = join("-", $seo_slug_array);
 return $seo_slug;
   }
   function seo_slugs_stop_words () {
   return array ("a", "able", "about", "above", "abroad", "according", "accordingly", "across", "actually", "adj", "after", "afterwards", "again", "against", "ago", "ahead", "ain't", "all", "allow", "allows", "almost", "alone", "along", "alongside", "already", "also", "although", "always", "am", "amid", "amidst", "among", "amongst", "an", "and", "another", "any", "anybody", "anyhow", "anyone", "anything", "anyway", "anyways", "anywhere", "apart", "appear", "appreciate", "appropriate", "are", "aren't", "around", "as", "a's", "aside", "ask", "asking", "associated", "at", "available", "away", "awfully", "b", "back", "backward", "backwards", "be", "became", "because", "become", "becomes", "becoming", "been", "before", "beforehand", "begin", "behind", "being", "believe", "below", "beside", "besides", "best", "better", "between", "beyond", "both", "brief", "but", "by", "c", "came", "can", "cannot", "cant", "can't", "caption", "cause", "causes", "certain", "certainly", "changes", "clearly", "c'mon", "co", "co.", "com", "come", "comes", "concerning", "consequently", "consider", "considering", "contain", "containing", "contains", "corresponding", "could", "couldn't", "course", "c's", "currently", "d", "dare", "daren't", "definitely", "described", "despite", "did", "didn't", "different", "directly", "do", "does", "doesn't", "doing", "done", "don't", "down", "downwards", "during", "e", "each", "edu", "eg", "eight", "eighty", "either", "else", "elsewhere", "end", "ending", "enough", "entirely", "especially", "et", "etc", "even", "ever", "evermore", "every", "everybody", "everyone", "everything", "everywhere", "ex", "exactly", "example", "except", "f", "fairly", "far", "farther", "few", "fewer", "fifth", "first", "five", "followed", "following", "follows", "for", "forever", "former", "formerly", "forth", "forward", "found", "four", "from", "further", "furthermore", "g", "get", "gets", "getting", "given", "gives", "go", "goes", "going", "gone", "got", "gotten", "greetings", "h", "had", "hadn't", "half", "happens", "hardly", "has", "hasn't", "have", "haven't", "having", "he", "he'd", "he'll", "hello", "help", "hence", "her", "here", "hereafter", "hereby", "herein", "here's", "hereupon", "hers", "herself", "he's", "hi", "him", "himself", "his", "hither", "hopefully", "how", "howbeit", "however", "hundred", "i", "i'd", "ie", "if", "ignored", "i'll", "i'm", "immediate", "in", "inasmuch", "inc", "inc.", "indeed", "indicate", "indicated", "indicates", "inner", "inside", "insofar", "instead", "into", "inward", "is", "isn't", "it", "it'd", "it'll", "its", "it's", "itself", "i've", "j", "just", "k", "keep", "keeps", "kept", "know", "known", "knows", "l", "last", "lately", "later", "latter", "latterly", "least", "less", "lest", "let", "let's", "like", "liked", "likely", "likewise", "little", "look", "looking", "looks", "low", "lower", "ltd", "m", "made", "mainly", "make", "makes", "many", "may", "maybe", "mayn't", "me", "mean", "meantime", "meanwhile", "merely", "might", "mightn't", "mine", "minus", "miss", "more", "moreover", "most", "mostly", "mr", "mrs", "much", "must", "mustn't", "my", "myself", "n", "name", "namely", "nd", "near", "nearly", "necessary", "need", "needn't", "needs", "neither", "never", "neverf", "neverless", "nevertheless", "new", "next", "nine", "ninety", "no", "nobody", "non", "none", "nonetheless", "noone", "no-one", "nor", "normally", "not", "nothing", "notwithstanding", "novel", "now", "nowhere", "o", "obviously", "of", "off", "often", "oh", "ok", "okay", "old", "on", "once", "one", "ones", "one's", "only", "onto", "opposite", "or", "other", "others", "otherwise", "ought", "oughtn't", "our", "ours", "ourselves", "out", "outside", "over", "overall", "own", "p", "particular", "particularly", "past", "per", "perhaps", "placed", "please", "plus", "possible", "presumably", "probably", "provided", "provides", "q", "que", "quite", "qv", "r", "rather", "rd", "re", "really", "reasonably", "recent", "recently", "regarding", "regardless", "regards", "relatively", "respectively", "right", "round", "s", "said", "same", "saw", "say", "saying", "says", "second", "secondly", "see", "seeing", "seem", "seemed", "seeming", "seems", "seen", "self", "selves", "sensible", "sent", "serious", "seriously", "seven", "several", "shall", "shan't", "she", "she'd", "she'll", "she's", "should", "shouldn't", "since", "six", "so", "some", "somebody", "someday", "somehow", "someone", "something", "sometime", "sometimes", "somewhat", "somewhere", "soon", "sorry", "specified", "specify", "specifying", "still", "sub", "such", "sup", "sure", "t", "take", "taken", "taking", "tell", "tends", "th", "than", "thank", "thanks", "thanx", "that", "that'll", "thats", "that's", "that've", "the", "their", "theirs", "them", "themselves", "then", "thence", "there", "thereafter", "thereby", "there'd", "therefore", "therein", "there'll", "there're", "theres", "there's", "thereupon", "there've", "these", "they", "they'd", "they'll", "they're", "they've", "thing", "things", "think", "third", "thirty", "this", "thorough", "thoroughly", "those", "though", "three", "through", "throughout", "thru", "thus", "till", "to", "together", "too", "took", "toward", "towards", "tried", "tries", "truly", "try", "trying", "t's", "twice", "two", "u", "un", "under", "underneath", "undoing", "unfortunately", "unless", "unlike", "unlikely", "until", "unto", "up", "upon", "upwards", "us", "use", "used", "useful", "uses", "using", "usually", "v", "value", "various", "versus", "very", "via", "viz", "vs", "w", "want", "wants", "was", "wasn't", "way", "we", "we'd", "welcome", "well", "we'll", "went", "were", "we're", "weren't", "we've", "what", "whatever", "what'll", "what's", "what've", "when", "whence", "whenever", "where", "whereafter", "whereas", "whereby", "wherein", "where's", "whereupon", "wherever", "whether", "which", "whichever", "while", "whilst", "whither", "who", "who'd", "whoever", "whole", "who'll", "whom", "whomever", "who's", "whose", "why", "will", "willing", "wish", "with", "within", "without", "wonder", "won't", "would", "wouldn't", "x", "y", "yes", "yet", "you", "you'd", "you'll", "your", "you're", "yours", "yourself", "yourselves", "you've", "z", "zero");
   }

When adding the additional code below to your functions.php file it will remove/hide the slug option for the screen options dropdown as well as the metabox.

// HIDE THE SLUG METABOX AND SLUG SCREEN OPTIONS
   function hide_slug_options() {
 global $post;
 global $pagenow;
 $hide_slugs = "<style type=\"text/css\">#slugdiv, #edit-slug-box, [for=\"slugdiv-hide\"] { display: none; }</style>\n";
 if (is_admin() && $pagenow=='post-new.php' OR $pagenow=='post.php') print($hide_slugs);
   }
   add_action( 'admin_head', 'hide_slug_options'  );

Exclude child categories of a specific category.

Pretty straight forward, but I couldn't find anyone doing exactly what I needed. Also it will display the post if the parent category is selected, except if that post has a child category of that parent selected.

   /* this code excludes all of the children of (category id = 20) posts
       on the HOME page, but allows parent (category id = 20) to be shown. */

    function exclude_category_children($query) {
        $child_cats = (array) get_term_children('20', 'category');
        if ( $query->is_home ) {
        $query->set('category__not_in', $child_cats);
        return $query;
        }
    }
    add_filter('pre_get_posts', 'exclude_category_children');

Make WordPress Editor Allow iFrames

// make TinyMCE allow iframes
add_filter('tiny_mce_before_init', create_function( '$a',
'$a["extended_valid_elements"] = "iframe[id|class|title|style|align|frameborder|height|longdesc|marginheight|marginwidth|name|scrolling|src|width]"; return $a;') );

Remove Admin Backend Menus for all users, except User #1 (usually the first Admin)

/*-----------------------------------------------------------------------------------*/
/*  Restrict access
/*-----------------------------------------------------------------------------------*/
function remove_menus () {
global $menu;
$user = wp_get_current_user();
    if ($user->ID!=1) { // Is not administrator,

        $restricted = array(__('Dashboard'), __('Posts'), __('Media'), __('Links'), __('Pages'), __('Appearance'), __('Tools'), __('Users'), __('Settings'), __('Comments'), __('Plugins'));
        end ($menu);
        while (prev($menu)){
            $value = explode(' ',$menu[key($menu)][0]);
            if(in_array($value[0] != NULL?$value[0]:"" , $restricted)){unset($menu[key($menu)]);}
        }
    }
}
add_action('admin_menu', 'remove_menus');

Disable browser upgrade warning in wordpress 3.2

//Disable browser upgrade warning in wordpress 3.2
function disable_browser_upgrade_warning() {
    remove_meta_box( 'dashboard_browser_nag', 'dashboard', 'normal' );
}
add_action( 'wp_dashboard_setup', 'disable_browser_upgrade_warning' );

Show template files being included

Display inline comment with Template File and get_template_part files being included when rendering pages. Handy for troubleshooting multipart templates.

add_action('all','template_snoop');
function template_snoop(){
    $args = func_get_args();
    if( !is_admin() and $args[0] ){
        if( $args[0] == 'template_include' ) {
            echo "<!-- Base Template: {$args[1]} -->\n";
        } elseif( strpos($args[0],'get_template_part_') === 0 ) {
            global $last_template_snoop;
            if( $last_template_snoop )
                echo "\n\n<!-- End Template Part: {$last_template_snoop} -->";
            $tpl = rtrim(join('-',  array_slice($args,1)),'-').'.php';
            echo "\n<!-- Template Part: {$tpl} -->\n\n";
            $last_template_snoop = $tpl;
        }
    }
}

is_tree() conditional Function

/* Adapted from csstricks with addition of
ancestors .... use = if(is_tree($id)) { // do stuff } ... Returns true if the
page is  = $id OR any of it's children OR descendants */

function is_tree($pid) {      // $pid = The ID of the page we're looking for pages underneath
  global $post;         // load details about this page
  $ancestors = get_post_ancestors($post);
  if(is_page()&&($post->post_parent==$pid||is_page($pid)||(in_array($pid,$ancestors))))
    return true;   // we're at the page or at a sub page
  else
    return false;  // we're elsewhere 
  };

Display the users that have submitted the most comments without a plugin

function top_comment_authors($amount = 5) {
global $wpdb;
$results = $wpdb->get_results('
    SELECT
    COUNT(comment_author_email) AS comments_count, comment_author_email, comment_author, comment_author_url
    FROM '.$wpdb->comments.'
    WHERE comment_author_email != "" AND comment_type = "" AND comment_approved = 1
    GROUP BY comment_author_email
    ORDER BY comments_count DESC, comment_author ASC
    LIMIT '.$amount
);
$output = "<ul>";
foreach($results as $result) {
    $output .= "<li>".$result->comment_author."</li>";
}
$output .= "</ul>";
echo $output;
}

Other options you can call: $result->comment_author_email $result->comments_count $result->comment_author_url

Get the Users Real IP Address whenever possible

Tested on: Wordpress 3.0.1

If you're using a proxy or load balancer, adding this to your wp-config.php file or functions.php

// Gets the user's real IP address

$_SERVER['REMOTE_ADDR'] = getRealIpAddress();
function getRealIpAddress( $validate = true ) {
    if ( isset($_SERVER['HTTP_X_FORWARDED_FOR']) && !empty($_SERVER['HTTP_X_FORWARDED_FOR']) ) {
        $ips = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
        $ip = trim($ips[count($ips) - 1]);
    } elseif ( isset($_SERVER['HTTP_X_REAL_IP']) && !empty($_SERVER['HTTP_X_REAL_IP']) ) {
        $ip = $_SERVER['HTTP_X_REAL_IP'];
    } elseif ( isset($_SERVER['HTTP_CLIENT_IP']) && !empty($_SERVER['HTTP_CLIENT_IP']) ) {
        $ip = $_SERVER['HTTP_CLIENT_IP'];
    } else {
        $ip = $_SERVER['REMOTE_ADDR'];
    }
    
    if ( $validate && function_exists('filter_var') &&  filter_var($ip, FILTER_VALIDATE_IP, array('flags' => FILTER_FLAG_IPV4, FILTER_FLAG_NO_PRIV_RANGE, FILTER_FLAG_NO_RES_RANGE)) )
        return $ip;
    elseif ( $validate )
        return long2ip(ip2long($ip));

    return $ip;
}

Exclude default category from public pages

Excludes the default category from the front-facing side of the website.
Code excludes the admin area, else you'll have no way to manage posts assigned with the default category.

add_filter( 'list_terms_exclusions', 'exclude_default_cat' );

function exclude_default_cat( $exclusions ) {
    if( !is_admin() )
        $exclusions .=  "AND t.term_id != " . get_option( 'default_category' ) . " ";
    return $exclusions;
}

Remove "Comments" link from admin bar if comment status is closed

You can set the default comment status to 'closed', but the comments link will stay. Simply drop the following into your functions.php file to get rid of it based on the condition. Offers 2 different approaches.

/**
 * Disable 'Comments' link if default status is _closed_
 */
function remove_comments() 
{
    $default_comment_status = get_option( 'default_comment_status' );

    if ( $default_comment_status == 'closed' ) 
    {
        remove_action( 'admin_bar_menu', 'wp_admin_bar_comments_menu', 50 );

        // optional solution using the WP_Admin_Bar class from /wp-includes/class-wp-admin-bar.php
        # global $wp_admin_bar;
        # $wp_admin_bar->remove_menu( 'comments' );
    }
    else 
    {
        return;
    }
}

Adds a custom dropdown option to WP_NAV_MENUS where the user can select a predefined css class for each menu item

<?php function menu_item_class_select(){
    global $pagenow;
    if ($pagenow == "nav-menus.php"){
?>

<script>
jQuery(document).ready(function(){
    function create_dd(v){
        //create dropdown
        var dd = jQuery('<select class="my_class"></select>');
        //create dropdown options
        //array with the options you want
        var classes = ["","class1","class2","class3"];
        jQuery.each(classes, function(i,val) {
            if (v == val){
                dd.append('<option value="'+val+'" selected="selected">'+val+'</option>');
            }else{
                dd.append('<option value="'+val+'">'+val+'</option>');
            }
        });
        return dd;
    }
    jQuery(".edit-menu-item-classes").each(function() {
        //add dropdown
        var t = create_dd(jQuery(this).val());
        jQuery(this).before(t);
        //hide all inputs
        jQuery(this).css("display","none");
    });
    //update input on selection
    jQuery(".my_class").bind("change", function() {
        var v = jQuery(this).val();
        var inp = jQuery(this).next();
        inp.attr("value",v);
    });
});
</script>

<?php } }
add_action('admin_footer','menu_item_class_select');
?>

source: https://wordpress.stackexchange.com/a/33816/479

Remove WordPress 3.3 Admin Bar Menu Items

function dashboard_tweaks() {
    global $wp_admin_bar;
    $wp_admin_bar->remove_menu('wp-logo');
    $wp_admin_bar->remove_menu('about');
    $wp_admin_bar->remove_menu('wporg');
    $wp_admin_bar->remove_menu('documentation');
    $wp_admin_bar->remove_menu('support-forums');
    $wp_admin_bar->remove_menu('feedback');
    $wp_admin_bar->remove_menu('view-site');
}
add_action( 'wp_before_admin_bar_render', 'dashboard_tweaks' );

Reference: http://pastebin.com/Wrk0JPxw

Cross Taxonomy Tags Query

A cached query that outputs a get_tags() like HTML string of all tags for a given Taxonomy parameter defaulting to a Category. You can use $where_slug and $where_tax to get post tags filtered by any other taxonomy. SQL tested for WP 3.1 to WP 3.3.1.

function tags_by_other_taxonomy($where_slug,$where_tax = 'category',$bust_cache = false) {
    $cache_key = "{$where_slug}:{$where_tax}";
    $cache = get_transient('tags_by_other_taxonomy');
    $html = '';
    if( true !== $bust_cache and false !== $cache and isset($cache[$cache_key]) and !empty($cache[$cache_key]) ) {
            $html = $cache[$cache_key];
    } else {
        global $wpdb;
        $cat_id = $wpdb->get_var("SELECT tt.term_taxonomy_id FROM $wpdb->terms t INNER JOIN $wpdb->term_taxonomy tt ON t.term_id = tt.term_id WHERE t.slug = '{$where_slug}' AND tt.taxonomy = '{$where_tax}' LIMIT 1");
        if( !empty($cat_id) ) {
            $cat_posts = $wpdb->get_col("SELECT tr.object_id FROM $wpdb->term_relationships tr inner join $wpdb->posts p ON p.ID = tr.object_id WHERE term_taxonomy_id = {$cat_id} AND p.post_status = 'publish' AND p.post_type = 'post'");
            if( count($cat_posts) ) {
                $tags = $wpdb->get_results("SELECT DISTINCT t.name,t.slug FROM $wpdb->term_taxonomy tt
                                INNER JOIN $wpdb->term_relationships tr ON tt.term_taxonomy_id = tr.term_taxonomy_id
                                INNER JOIN $wpdb->terms t ON t.term_id = tt.term_id
                                WHERE tt.taxonomy = 'post_tag' and tr.object_id IN (".implode(',',$cat_posts) .')');
                $html = '<ul class="post-tags-'.$where_slug.'">';
                if( count($tags) ) {
                    foreach($tags as $tag)
                        $html .= '<li><a href="/tag/'.$tag->slug.'/" title="Posts tagged with '.$tag->name.'">'.$tag->name.'</a></li>';
                }
                $html .= '</ul>';
                if( !is_array($cache) )
                    $cache = array();
                $cache[$cache_key] = $html;
                set_transient('sc_cross_tax', $cache, 86400);
            }
        }
    }
    echo $html;
}

For example, get all tags for Published Posts in the news Category slug:

<?php echo tags_by_other_taxonomy('news'); ?>

Automatically adding header images from directory location

Within the default them which comes with wordpress you will notice an additional theme menu which gets activated that lets you select a header image to be utilized. Within the default theme code these images are hardcoded into the functions.php file. The code below allows wordpress to automatically pick up new images based upon a specific header image directly you can create on your server (or within your themes folder).

It will automatically include any .jpg or .jpeg files. Every image must have a associating thumbnail file but this can just be a copy of the original with a different name with a file name that has to end in "-thumbnail". The associating name is used as the description in the headers appearance settings and underscores are automatically replaced with spaces. (e.g. My_Header_Image_A.jpg, My_Header_Image_A=thumbnail.jpg will have a description automatically presented a “My Header Image A”)

if ($handle = opendir( TEMPLATEPATH . '/images/headers/') ) {
    $headers = array();
    while (false !== ($file = readdir($handle))) {
        $pos = strrpos( $file, '.' );
        if( $pos !== false && $pos > 0 ) {
            $file_name = substr( $file, 0, $pos );
            if( strpos( $file_name, "-thumbnail" ) === false ) {
                $file_ext = substr( $file, $pos+1 );
                $file_ext_low = strtolower( $file_ext );
                if( $file_ext_low == "jpg" || $file_ext_low == "jpeg" ) {
                    $headers[$file_name] = array (
                    'url' => '%s/images/headers/' . $file,
                    'thumbnail_url' => '%s/images/headers/' . $file_name ."-thumbnail." . $file_ext,
                    'description' => __( str_replace( "_", " ", $file_name ), 'twentyten' )
                    );
                }
            }
        }
    }
closedir($handle);
register_default_headers( $headers );
}

Displaying information for logged in users

if ( is_user_logged_in() ) {

}

is not working in functions.php file. You can use this code:

if ( !function_exists('is_user_logged_in') ) :

 function is_user_logged_in() {
$user = wp_get_current_user();

if ( $user->id == 0 ){
// This section if user is not logged in
} else {
// This section if user is logged in
}
}
endif;

Custom Logos for Login page and Admin

/*-----------------------------------------------------------------------------------*/
/*  Custom logos
/*-----------------------------------------------------------------------------------*/
function custom_admin_logo() {
    echo '
        <style type="text/css">
            #header-logo { background-image: url('.get_bloginfo('template_directory').'/path/to/images/admin-logo.png) !important; }
        </style>
    ';
}
add_action('admin_head', 'custom_admin_logo');

function custom_login_logo() {
    echo '<style type="text/css">
        h1 a { background-image:url('.get_bloginfo('template_directory').'/path/to/images/login-logo.png) !important; }
    </style>';
}

add_action('login_head', 'custom_login_logo');

Remove Admin (User #1) from User list

function your_pre_user_query($user_search) {
  $user = wp_get_current_user();
  if ($user->ID!=1) {
    global $wpdb;
    $user_search->query_where = str_replace('WHERE 1=1',
      "WHERE 1=1 AND {$wpdb->users}.ID<>1",$user_search->query_where);
  }
}
add_action('pre_user_query','your_pre_user_query');

Get Attributes of Given Thumbnail

Use this function with the loop to determine width, height and URL of a thumbnailed image. Very handy for assigning a thumbnailed image as a background element via inline CSS.

/**
* GET THUMBNAIL ATTRIBUTES
*
* Fetches width, heigth and URI of a thumbnail.
*
* @author Philip Downer <philip@manifestbozeman.com>
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
* @version v1.0
*
* @param string $return Accepts 'path', 'width', or 'height'.
* @param string $size The thumbnail size corresponding to {@link add_image_size() WP core function}.
* @return mixed Returns the requested info, or if no 'Featured Image' assigned, returns 'false'.
*/
function get_thumb_attr($return,$size='thumbnail') {
    global $post;

    if (has_post_thumbnail($post->ID)) {
      $thumb = wp_get_attachment_image_src(get_post_thumbnail_id(), 'intro');
      if ( $return == 'path' ) { return $thumb[0]; }
      if ( $return == 'width' ) { return $thumb[1]; }
      if ( $return == 'height' ) { return $thumb[2]; }
    } else {
        return false;
    }
}//end function

Output the contents of a widget outside the context of a sidebar using it's ID. The wrapping before/after HTML is not included. You need to know the specific ID of the widget you're angling for (ie 'text-5').

function widget_contents($id) {
    list($type,$number) = explode('-',$id);
    global $wp_registered_widgets;
    $wp_registered_widgets[$id]['callback'][0]->display_callback(array('widget_id'=>$id),$number);
}

You can peek at the output of wp_get_sidebars_widgets() if you aren't sure of the precise ID you need.

A more complete example lifted from /wp-includes/widgets.php under the dynamic_sidebar() function:

function render_widget($id) {
    global $wp_registered_widgets;
    $params = array_merge(
            array( array('widget_id' => $id, 'widget_name' => $wp_registered_widgets[$id]['name']) ),
            (array) $wp_registered_widgets[$id]['params']
    );
    $classname_ = '';
    foreach ( (array) $wp_registered_widgets[$id]['classname'] as $cn ) {
            if ( is_string($cn) )
                    $classname_ .= '_' . $cn;
            elseif ( is_object($cn) )
                    $classname_ .= '_' . get_class($cn);
    }
    $classname_ = ltrim($classname_, '_');
    $params[0]['before_widget'] = sprintf($params[0]['before_widget'], $id, $classname_);

    if ( is_callable($wp_registered_widgets[$id]['callback']) )
            call_user_func_array($wp_registered_widgets[$id]['callback'], $params);
}

Custom smilies (plugin)

/**
 * Smilies.
 */
function filter_smilies_src($img_src, $img, $siteurl) {
    return plugins_url('', __FILE__) . '/img/smilies/' . $img;
}
add_filter('smilies_src', 'filter_smilies_src', 1, 10);

Custom smilies (theme)

/**
 * Smilies.
 */
function filter_smilies_src($img_src, $img, $siteurl) {
    return get_bloginfo('stylesheet_directory') . '/images/smilies/' . $img;
}
add_filter('smilies_src', 'filter_smilies_src', 1, 10);

Reposition the WYSIWYG Editor through JQUERY

Tested on: Wordpress 3.0.1

This code will allow you to remove specific meta boxes which wordpress adds by default to the POST and PAGES screens.

// REPOSITION WYSIWYG EDITOR THROUGH JQUERY
   add_action('admin_head','admin_head_hook');
   function admin_head_hook() {
 ?><style type="text/css">
  #postdiv.postarea, #postdivrich.postarea { margin:0; }
  #post-status-info { line-height:1.4em; font-size:13px; }
  .custom-wysiwyg-editor-container { margin:2px 6px 6px 6px; }
  #ed_toolbar { display:none; }
  #postdiv #ed_toolbar, #postdivrich #ed_toolbar { display:block; }
 </style><?php
   }

   add_action('admin_footer','admin_footer_hook');
   function admin_footer_hook() {
 ?><script type="text/javascript">
  jQuery('#postdiv, #postdivrich').prependTo('.custom-wysiwyg-editor-container');
 </script><?php
   }

Automatically close missing tags from the WYSIWYG editor

Tested on: Wordpress 3.0.1

This code will automatically close any missing tags when using the WYSIWYG editor.

// AUTOMATICALLY CLEAN UP HTML WYSIWYG EDITOR BY CLOSING MISSING TAGS
   function clean_bad_content($bPrint = false) {
 global $post;
 $szPostContent  = $post->post_content;
 $szRemoveFilter = array("~<p[^>]*>\s?</p>~", "~<a[^>]*>\s?</a>~", "~<font[^>]*>~", "~<\/font>~", "~style\=\"[^\"]*\"~", "~<span[^>]*>\s?</span>~");
 $szPostContent  = preg_replace($szRemoveFilter, '', $szPostContent);
 $szPostContent  = apply_filters('the_content', $szPostContent);
 if ($bPrint == false) return $szPostContent; 
 else echo $szPostContent;
   }

Remove role="search" attributes for get_search_form()

function remove_role_search($role)
{
    $result = array();
    preg_match_all('|role="[^"]*"|U', $role, $result);
    foreach ($result[0] as $role_tag) {
        $role = str_replace($role_tag, '', $role);
    }
    return $role;
}
add_filter('get_search_form', 'remove_role_search');

Add a Login Link to wp_nav_menu

//ADD LOGIN LINK TO MENU
add_filter('wp_nav_menu_items', 'add_login_logout_link', 10, 2);

function add_login_logout_link($items, $args) { 

        $loginoutlink = wp_loginout('index.php', false); 

        $items .= '<li>'. $loginoutlink .'</li>'; 

    return $items; 
}

Changing "Posts" menu name in admin to whatever you wish (e.g. "Articles")

// hook the translation filters
add_filter('gettext','change_post_to_article');
add_filter('ngettext','change_post_to_article');

function change_post_to_article( $translated ) {
$translated = str_ireplace('Post','Article',$translated );// ireplace is PHP5 only
return $translated;
}

Credits to smashingmagazine.com ^[1]

Remove Links Menu Item

Many of my WordPress installs don't require that users have access to the 'Links' menu item. This function removes it from view.

add_action( 'admin_menu', 'custom_admin_menu' );
function custom_admin_menu() 
{
    global $menu;
    // var_dump($menu); // use this to identify the key for the menu item you want to remove
    unset( $menu[15] ); //key 15 is links
    if ( !current_user_can('manage_options') ) { unset( $menu[75] ); } //key 75 is tools ... but only for non super admins
}

Disable Upgrade Now Message for Non-Administrators

I'm actually a big fan of NOT using this code. Instead, I prefer to allow customers to update their own WordPress installs. This helps keep the site up-to-date and forces me to write better code.

if ( !current_user_can( 'manage_options' ) ) {
  add_action( 'init', create_function( '$a', "remove_action( 'init', 'wp_version_check' );" ), 2 );
  add_filter( 'pre_option_update_core', create_function( '$a', "return null;" ) );
}

Automatically add a hidden custom field and associating value to a post when the post is published

add_action('publish_page', 'add_custom_field_automatically');
add_action('publish_post', 'add_custom_field_automatically');
function add_custom_field_automatically($post_ID) {
global $wpdb;
if(!wp_is_post_revision($post_ID)) {
    add_post_meta($post_ID, 'field-name', 'custom value', true);
}
}

Call bloginfo using shortcode...

function digwp_bloginfo_shortcode($atts) {
    
    extract(shortcode_atts(array(
            'key' => '',
            ), $atts));
    
    return get_bloginfo($key);
}

add_shortcode('bloginfo', 'digwp_bloginfo_shortcode');

Usage:

[bloginfo key='name']

Add a custom class to the next and previous links

add_filter('next_posts_link_attributes', 'posts_link_attributes');
add_filter('previous_posts_link_attributes', 'posts_link_attributes');
function posts_link_attributes(){
    return 'class="styled-button"';
    }

Add custom post types to archives page

function namespace_add_custom_types( $query ) {
if( is_category() || is_tag() && empty( $query->query_vars['suppress_filters'] ) ) {
$query->set( 'post_type', array(
 'post', 'your-custom-post-type-here'
            ));
      return $query;
    }
}
add_filter( 'pre_get_posts', 'namespace_add_custom_types' );