wp functions
1.0.0
This is a list of useful WordPress functions that I often reference to enhance or clean up my sites. Please be careful and make backups.
Hide WordPress Update Nag to All But Admins
Utilize Proper WordPress Titles
Create Custom WordPress Dashboard Widget
Remove All Dashboard Widgets
Include Navigation Menus
Insert Custom Login Logo
Modify Admin Footer Text
Enqueue Styles and Scripts
Enqueue Google Fonts
Modify Excerpt Length
Change Read More Link
Change More Excerpt
Disable Emoji Mess
Remove Comments
Change Media Gallery URL
Create Custom Thumbnail Size
Add Categories for Attachments
Add Tags for Attachments
Add Custom Excerpt to Pages
Create a Global String
Support Featured Images
Support Search Form
Excluding pages from search
Disable XMLRPC
Escape HTML in Posts
Create Custom Global Settings
Remove WordPress Admin Bar
Add Open Graph Meta Tags
Add Custom Post Type
Implement Preconnect to Google Fonts in Themes
Add Thumbnail Column to Post Listing
Add Lead Class to First Paragraph
Exclude Custom Post Type from Search
Remove Query String from Static Resources
Disable Website Field From Comment Form
Modify jQuery
Disable JSON Rest API
Switch Post Type
PHP Logger
Always Show Second Bar in TinyMCE
Remove Admin Menu Items Depending on User Role
Remove Admin Menu Items Depending on Email Address (Domain)
Reorder Admin Menu Items
Exclude a Category From WordPress Loops
Disable the message "JQMIGRATE: Migrate is installed, version 1.4.1"
Load heavy 3rd-party scripts later for better performance
/** * Hide WordPress update nag to all but admins */ function hide_update_notice_to_all_but_admin() { if ( !current_user_can( 'update_core' ) ) { remove_action( 'admin_notices', 'update_nag', 3 );
}
}add_action( 'admin_head', 'hide_update_notice_to_all_but_admin', 1 );Make sure to remove the <title> tag from your header.
/** * Utilize proper WordPress titles */add_theme_support( 'title-tag' );
/** * Create custom WordPress dashboard widget */ function dashboard_widget_function() { echo ' <h2>Custom Dashboard Widget</h2> <p>Custom content here</p> ';
}function add_dashboard_widgets() { wp_add_dashboard_widget( 'custom_dashboard_widget', 'Custom Dashoard Widget', 'dashboard_widget_function' );
}add_action( 'wp_dashboard_setup', 'add_dashboard_widgets' );/** * Remove all dashboard widgets */ function remove_dashboard_widgets() { global $wp_meta_boxes;
unset( $wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press'] );
unset( $wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links'] );
unset( $wp_meta_boxes['dashboard']['normal']['core']['dashboard_right_now'] );
unset( $wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins'] );
unset( $wp_meta_boxes['dashboard']['normal']['core']['dashboard_recent_drafts'] );
unset( $wp_meta_boxes['dashboard']['normal']['core']['dashboard_recent_comments'] );
unset( $wp_meta_boxes['dashboard']['side']['core']['dashboard_primary'] );
unset( $wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary'] ); remove_meta_box( 'dashboard_activity', 'dashboard', 'normal' );
}add_action( 'wp_dashboard_setup', 'remove_dashboard_widgets' );/** * Include navigation menus */function register_my_menu() { register_nav_menu( 'nav-menu', __( 'Navigation Menu' ) );
}add_action( 'init', 'register_my_menu' );Insert this where you want it to appear, and save the menu in Appearance -> Menus.
wp_nav_menu( array( 'theme_location' => 'nav-menu' ) );
Here's the code for multiple menus:
function register_my_menus() { register_nav_menus( array( 'new-menu' => __( 'New Menu' ), 'another-menu' => __( 'Another Menu' ), 'an-extra-menu' => __( 'An Extra Menu' ),
)
);
}add_action( 'init', 'register_my_menus' );/** * Insert custom login logo */ function custom_login_logo() { echo ' <style> .login h1 a { background-image: url(image.jpg) !important; background-size: 234px 67px; width:234px; height:67px; display:block; } </style> ';
}add_action( 'login_head', 'custom_login_logo' );/** * Modify admin footer text */ function modify_footer() { echo 'Created by <a href="mailto:[email protected]">you</a>.';
}add_filter( 'admin_footer_text', 'modify_footer' );/** * Enqueue styles and scripts */ function custom_scripts() { wp_enqueue_style( 'bootstrap', get_template_directory_uri() . '/css/bootstrap.min.css', array(), '3.3.6' ); wp_enqueue_style( 'style', get_template_directory_uri() . '/css/style.css' ); wp_enqueue_script( 'bootstrap', get_template_directory_uri() . '/js/bootstrap.min.js', array('jquery'), '3.3.6', true ); wp_enqueue_script( 'script', get_template_directory_uri() . '/js/script.js' );
}add_action( 'wp_enqueue_scripts', 'custom_scripts' );/** * Enqueue Google Fonts */ function google_fonts() { wp_register_style( 'OpenSans', '//fonts.googleapis.com/css?family=Open+Sans:400,600,700,800' ); wp_enqueue_style( 'OpenSans' );
}add_action( 'wp_print_styles', 'google_fonts' );/** * Modify excerpt length */ function custom_excerpt_length( $length ) { return 25;
}add_filter( 'excerpt_length', 'custom_excerpt_length', 999 );/** * Change Read More link */ function custom_read_more_link() { return '<a href="' . get_permalink() . '">Read More</a>';
}add_filter( 'the_content_more_link', 'custom_read_more_link' );/** * Change More excerpt */ function custom_more_excerpt( $more ) { return '...';
}add_filter( 'excerpt_more', 'custom_more_excerpt' );/** * Disable Emoji mess */ function disable_wp_emojicons() { remove_action( 'admin_print_styles', 'print_emoji_styles' ); remove_action( 'wp_head', 'print_emoji_detection_script', 7 ); remove_action( 'admin_print_scripts', 'print_emoji_detection_script' ); remove_action( 'wp_print_styles', 'print_emoji_styles' ); remove_filter( 'wp_mail', 'wp_staticize_emoji_for_email' ); remove_filter( 'the_content_feed', 'wp_staticize_emoji' ); remove_filter( 'comment_text_rss', 'wp_staticize_emoji' ); add_filter( 'tiny_mce_plugins', 'disable_emojicons_tinymce' ); add_filter( 'emoji_svg_url', '__return_false' );
}add_action( 'init', 'disable_wp_emojicons' );function disable_emojicons_tinymce( $plugins ) { return is_array( $plugins ) ? array_diff( $plugins, array( 'wpemoji' ) ) : array();
}/** * Remove comments */ // Removes from admin menufunction my_remove_admin_menus() { remove_menu_page( 'edit-comments.php' );
}add_action( 'admin_menu', 'my_remove_admin_menus' );// Removes from post and pagesfunction remove_comment_support() { remove_post_type_support( 'post', 'comments' ); remove_post_type_support( 'page', 'comments' );
}add_action( 'init', 'remove_comment_support', 100 );// Removes from admin barfunction mytheme_admin_bar_render() { global $wp_admin_bar;
$wp_admin_bar->remove_menu( 'comments' );
}add_action( 'wp_before_admin_bar_render', 'mytheme_admin_bar_render' );/** * Change Media Gallery URL */ if ( empty( get_option( 'upload_url_path' ) ) ) { update_option( 'upload_url_path', 'http://assets.website.com/wp-content/uploads' );
}Also, you can filter the option value before it's retrieved from the database, which is slightly better:
/** * Change Media Gallery URL */ add_filter( 'pre_option_upload_url_path', function() { return 'http://assets.website.com/wp-content/uploads';
});/** * Create custom thumbnail size */ add_image_size( 'custom-thumbnail', 250, 250, true );
Retrieve Thumbnail
$thumb = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), 'custom-thumbnail' );echo $thumb[0];
Since WordPress 4.4.0, you can use:
the_post_thumbnail_url( $size );
/** * Add categories for attachments */ function add_categories_for_attachments() { register_taxonomy_for_object_type( 'category', 'attachment' );
}add_action( 'init' , 'add_categories_for_attachments' );/** * Add tags for attachments */ function add_tags_for_attachments() { register_taxonomy_for_object_type( 'post_tag', 'attachment' );
}add_action( 'init' , 'add_tags_for_attachments' );/** * Add custom excerpt to pages */ function add_page_excerpt() { add_post_type_support( 'page', array( 'excerpt' ) );
}add_action( 'init', 'add_page_excerpt' );/** * Create a global string */ function global_string() { return 'String';
}Retrieve Field
echo global_string();
/** * Support featured images */ add_theme_support( 'post-thumbnails' );
/** * Support search form */ add_theme_support( 'html5', array( 'search-form' ) );
/** * Excluding pages from search */ function exclude_pages_from_search() { global $wp_post_types; $wp_post_types['page']->exclude_from_search = true;
}add_action( 'init', 'exclude_pages_from_search' );/** * Disable xmlrpc.php */ add_filter( 'xmlrpc_enabled', '__return_false' );remove_action( 'wp_head', 'rsd_link' );remove_action( 'wp_head', 'wlwmanifest_link' );
/** * Escape HTML in <code> or <pre><code> tags. */ function escapeHTML($arr) { if (version_compare(PHP_VERSION, '5.2.3') >= 0) { $output = htmlspecialchars($arr[2], ENT_NOQUOTES, get_bloginfo('charset'), false);
} else { $specialChars = array( '&' => '&', '<' => '<', '>' => '>'
); // decode already converted data $data = htmlspecialchars_decode( $arr[2] ); // escape all data inside <pre> $output = strtr( $data, $specialChars );
} if (! empty($output)) { return $arr[1] . $output . $arr[3];
} else { return $arr[1] . $arr[2] . $arr[3];
}
}function filterCode($data) { // Uncomment if you want to escape anything within a <pre> tag //$modifiedData = preg_replace_callback( '@(<pre.*>)(.*)(</pre>)@isU', 'escapeHTML', $data ); $modifiedData = preg_replace_callback( '@(<code.*>)(.*)(</code>)@isU', 'escapeHTML', $data ); $modifiedData = preg_replace_callback( '@(<tt.*>)(.*)(</tt>)@isU', 'escapeHTML', $modifiedData ); return $modifiedData;
}add_filter( 'content_save_pre', 'filterCode', 9 );add_filter( 'excerpt_save_pre', 'filterCode', 9 );Modified from Escape HTML.
/** * Create custom global settings */ function custom_settings_page() { ?>
<div class="wrap">
<h1>Custom Settings</h1>
<form method="post" action="options.php"> <?php settings_fields( 'section' ); do_settings_sections( 'theme-options' ); submit_button(); ?>
</form>
</div><?php }function custom_settings_add_menu() { add_theme_page( 'Custom Settings', 'Custom Settings', 'manage_options', 'custom-settings', 'custom_settings_page', null, 99 );
}add_action( 'admin_menu', 'custom_settings_add_menu' );// Example settingfunction setting_twitter() { ?>
<input type="text" name="twitter" id="twitter" value="<?php echo get_option('twitter'); ?>" /><?php }function custom_settings_page_setup() { add_settings_section( 'section', 'All Settings', null, 'theme-options' ); add_settings_field( 'twitter', 'Twitter Username', 'setting_twitter', 'theme-options', 'section' ); register_setting( 'section', 'twitter' );
}add_action( 'admin_init', 'custom_settings_page_setup' );Retrieve Field
echo get_option( 'twitter' );
Modified from Create a WordPress Theme Settings Page with the Settings API.
/** * Remove WordPress admin bar */function remove_admin_bar() { remove_action( 'wp_head', '_admin_bar_bump_cb' );
}add_action( 'get_header', 'remove_admin_bar' );/** * Add Open Graph Meta Tags */function meta_og() { global $post; if ( is_single() ) { if( has_post_thumbnail( $post->ID ) ) { $img_src = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'thumbnail' );
}
$excerpt = strip_tags( $post->post_content ); $excerpt_more = ''; if ( strlen($excerpt ) > 155) { $excerpt = substr( $excerpt,0,155 ); $excerpt_more = ' ...';
} $excerpt = str_replace( '"', '', $excerpt ); $excerpt = str_replace( "'", '', $excerpt ); $excerptwords = preg_split( '/[nrt ]+/', $excerpt, -1, PREG_SPLIT_NO_EMPTY ); array_pop( $excerptwords ); $excerpt = implode( ' ', $excerptwords ) . $excerpt_more; ?><meta name="author" content="Your Name">
<meta name="description" content="<?php echo $excerpt; ?>">
<meta property="og:title" content="<?php echo the_title(); ?>">
<meta property="og:description" content="<?php echo $excerpt; ?>">
<meta property="og:type" content="article">
<meta property="og:url" content="<?php echo the_permalink(); ?>">
<meta property="og:site_name" content="Your Site Name">
<meta property="og:image" content="<?php echo $img_src[0]; ?>"><?php
} else { return;
}
}add_action('wp_head', 'meta_og', 5);/** * Add custom post type */function create_custom_post() { register_post_type( 'custom-post', // slug for custom post type array( 'labels' => array( 'name' => __( 'Custom Post' ),
), 'public' => true, 'hierarchical' => true,
'has_archive' => true, 'supports' => array( 'title', 'editor', 'excerpt', 'thumbnail'
),
'can_export' => true, 'taxonomies' => array( 'post_tag', 'category'
)
));
}add_action('init', 'create_custom_post');/** * Implement preconnect to Google Fonts in themes */function twentyfifteen_resource_hints( $urls, $relation_type ) { // Checks whether the subject is carrying the source of fonts google and the `$relation_type` equals preconnect. // Replace `enqueue_font_id` the `ID` used in loading the source. if ( wp_style_is( 'enqueue_font_id', 'queue' ) && 'preconnect' === $relation_type ) { // Checks whether the version of WordPress is greater than or equal to 4.7 // to ensure compatibility with older versions // because the 4.7 has become necessary to return an array instead of string if ( version_compare( $GLOBALS['wp_version'], '4.7-alpha', '>=' ) ) { // Array with url google fonts and crossorigin $urls[] = array( 'href' => 'https://fonts.gstatic.com', 'crossorigin',
);
} else { // String with url google fonts $urls[] = 'https://fonts.gstatic.com';
}
} return $urls;
}add_filter( 'wp_resource_hints', 'twentyfifteen_resource_hints', 10, 2 );/** * Add thumbnail column to post listing */add_image_size( 'admin-list-thumb', 80, 80, false );function wpcs_add_thumbnail_columns( $columns ) {
if ( !is_array( $columns ) ) $columns = array(); $new = array(); foreach( $columns as $key => $title ) { if ( $key == 'title' ) // Put the Thumbnail column before the Title column $new['featured_thumb'] = __( 'Image'); $new[$key] = $title;
} return $new;
}function wpcs_add_thumbnail_columns_data( $column, $post_id ) { switch ( $column ) { case 'featured_thumb': echo '<a href="' . $post_id . '">'; echo the_post_thumbnail( 'admin-list-thumb' ); echo '</a>'; break;
}
}if ( function_exists( 'add_theme_support' ) ) { add_filter( 'manage_posts_columns' , 'wpcs_add_thumbnail_columns' ); add_action( 'manage_posts_custom_column' , 'wpcs_add_thumbnail_columns_data', 10, 2 );
}/** * Add lead class to first paragraph */function first_paragraph( $content ) { return preg_replace( '/<p([^>]+)?>/', '<p$1 class="lead">', $content, 1 );
}add_filter( 'the_content', 'first_paragraph' );Adds a lead class to the first paragraph in the_content.
/** * Exclude custom post type from search */function excludePages( $query ) {if ( $query->is_search ) { $query->set( 'post_type', 'post' );
} return $query;
}add_filter( 'pre_get_posts','excludePages' );/** * Remove query string from static resources */ function remove_cssjs_ver( $src ) { if ( strpos( $src, '?ver=' ) ) $src = remove_query_arg( 'ver', $src ); return $src;
}add_filter( 'style_loader_src', 'remove_cssjs_ver', 10, 2 );add_filter( 'script_loader_src', 'remove_cssjs_ver', 10, 2 );/** * Modify jQuery */function modify_jquery() { wp_deregister_script( 'jquery' ); wp_register_script( 'jquery', 'https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js', false, '3.2.1' ); wp_enqueue_script( 'jquery' );
}if (!is_admin()) add_action('wp_enqueue_scripts', 'modify_jquery');/** * Disable website field from comment form */function disable_website_field( $field ) {
if( isset($field['url']) ) {
unset( $field['url'] );
} return $field;
}add_filter('comment_form_default_fields', 'disable_website_field');/** * Disable JSON REST API */add_filter('json_enabled', '__return_false');add_filter('json_jsonp_enabled', '__return_false');/** * Switch post type */function switch_post_type ( $old_post_type, $new_post_type ) { global $wpdb; // Run the update query $wpdb->update( $wpdb->posts, // Set array( 'post_type' => $new_post_type), // Where array( 'post_type' => $old_post_type )
);
}/** * PHP Logger */function php_logger( $data ) { $output = $data; if ( is_array( $output ) ) $output = implode( ',', $output );
// print the result into the JavaScript console echo "<script>console.log( 'PHP LOG: " . $output . "' );</script>";
}/** * Always show second bar in TinyMCE */function show_tinymce_toolbar( $in ) { $in['wordpress_adv_hidden'] = false; return $in;
}add_filter( 'tiny_mce_before_init', 'show_tinymce_toolbar' );/** * Clone the administrator user role */function clone_admin_role() { global $wp_roles; if ( ! isset( $wp_roles ) ) $wp_roles = new WP_Roles();
$adm = $wp_roles->get_role( 'administrator' );
// Add new "Client" role with all admin capabilities $wp_roles->add_role( 'client', 'Client', $adm->capabilities );
}add_action( 'init', 'clone_admin_role' );/** * Specify which admin menu items are visible for users with role "Client" */function remove_dashboard_menus() { if ( current_user_can( 'client' ) ) { // Hide Updates under Dashboard menu remove_submenu_page( 'index.php', 'update-core.php' ); // Hide Comments remove_menu_page( 'edit-comments.php' ); // Hide Plugins remove_menu_page( 'plugins.php' ); // Hide Themes, Customizer and Widgets under Appearance menu remove_submenu_page( 'themes.php', 'themes.php' ); remove_submenu_page( 'themes.php', 'customize.php?return=' . urlencode( $_SERVER['REQUEST_URI'] ) ); remove_submenu_page( 'themes.php', 'widgets.php' ); // Hide Tools remove_menu_page( 'tools.php' ); // Hide General Settings remove_menu_page( 'options-general.php' );
}
}add_action( 'admin_menu', 'remove_dashboard_menus' );/** * Specify which users can see admin menu items based on their email address */function remove_dashboard_menus() { $user_data = get_userdata( get_current_user_id() ); $user_email = isset( $user_data->user_email ) ? $user_data->user_email : ''; if ( ! strpos( $user_email, '@yourcompany.com' ) ) { // Hide Updates under Dashboard menu remove_submenu_page( 'index.php', 'update-core.php' ); // Hide Comments remove_menu_page( 'edit-comments.php' ); // Hide Plugins remove_menu_page( 'plugins.php' ); // Hide Themes, Customizer and Widgets under Appearance menu remove_submenu_page( 'themes.php', 'themes.php' ); remove_submenu_page( 'themes.php', 'customize.php?return=' . urlencode( $_SERVER['REQUEST_URI'] ) ); remove_submenu_page( 'themes.php', 'widgets.php' ); // Hide Tools remove_menu_page( 'tools.php' ); // Hide General Settings remove_menu_page( 'options-general.php' );
}
}add_action( 'admin_menu', 'remove_dashboard_menus' );/** * Reorder admin menu */function custom_menu_order( $menu_ord ) { if ( ! $menu_ord ) { return true; } return array( 'index.php', 'separator1', 'edit.php?post_type=page',
'edit.php',
'edit.php?post_type=[your_post_type_slug]', 'upload.php', 'edit-comments.php', 'separator2', 'themes.php', 'plugins.php', 'users.php', 'tools.php', 'options-general.php'
);
}
}add_filter( 'custom_menu_order', 'custom_menu_order' );add_filter( 'menu_order', 'custom_menu_order' );/** * Exclude a category from all WordPress loops */add_action( 'pre_get_posts', function( $query ) { // anonymous callback
global $wp_query;
// Hard coded category ID, but can be dynamic: esc_attr(get_option('your-cat-id')); $excluded_cat_id = 25; // add category ID to existing, avoid overwriting it $cat[] = $query->get( 'cat' ); $cat[] = "-" . $excluded_cat_id; $query->set( 'cat', $cat );
}
});add_action('wp_default_scripts', function ($scripts) { if (!empty($scripts->registered['jquery'])) { $scripts->registered['jquery']->deps = array_diff($scripts->registered['jquery']->deps, ['jquery-migrate']);
}
});Lighthouse and similar performance analysis tools always complain about render-blocking scripts (and styles), short cache TTL etc. Most of these scripts and styles come from 3rd-party sources which we can't control – Google's own Tag Manager and Analytics, Facebook Pixel, other trackers and chat scripts etc. However, we can load them only when a real user interacts with a page, significantly reducing the Time To Interactive metric and scoring much higher performance results.
Depending on where you like these 3rd-party scripts to be, you can either use wp_footer action to print the
code in footer, or put it in your main app.js script which, in turn, is enqueued on wp_enqueue_scripts action.
<script>var fired = false;
window.addEventListener('scroll', () => { if (fired === false) { fired = true;
setTimeout(() => { // Marketing scripts go here. }, 1000) // 1000ms or 1s works fine, but you can adjust this timeout. }});</script> 
