Hide WordPress Update Nag to All But Admins

/** * Hide WordPress update nag to all but admins */functionhide_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 );

Utilize Proper WordPress Titles

/** * Utilize proper WordPress titles */add_theme_support('title-tag' );

Create Custom WordPress Dashboard Widget

/** * Create custom WordPress dashboard widget */functiondashboard_widget_function() {echo'        <h2>Custom Dashboard Widget</h2>        <p>Custom content here</p>';}functionadd_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

/** * Remove all dashboard widgets */functionremove_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

/** * Include navigation menus */functionregister_my_menu() {register_nav_menu('nav-menu',__('Navigation Menu' ) );}add_action('init','register_my_menu' );

wp_nav_menu(array('theme_location' =>'nav-menu' ) );

functionregister_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

/** * Insert custom login logo */functioncustom_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

/** * Modify admin footer text */functionmodify_footer() {echo'Created by <a href="mailto:you@example.com">you</a>.';}add_filter('admin_footer_text','modify_footer' );

Enqueue Styles and Scripts

/** * Enqueue styles and scripts */functioncustom_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

/** * Enqueue Google Fonts */functiongoogle_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

/** * Modify excerpt length */functioncustom_excerpt_length($length ) {return25;}add_filter('excerpt_length','custom_excerpt_length',999 );

Change Read More Link

/** * Change Read More link */functioncustom_read_more_link() {return'<a href="' .get_permalink() .'">Read More</a>';}add_filter('the_content_more_link','custom_read_more_link' );

Change More Excerpt

/** * Change More excerpt */functioncustom_more_excerpt($more ) {return'...';}add_filter('excerpt_more','custom_more_excerpt' );

Disable Emoji Mess

/** * Disable Emoji mess */functiondisable_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' );functiondisable_emojicons_tinymce($plugins ) {returnis_array($plugins ) ?array_diff($plugins,array('wpemoji' ) ) :array();}

Remove Comments

/** * Remove comments */// Removes from admin menufunctionmy_remove_admin_menus() {remove_menu_page('edit-comments.php' );}add_action('admin_menu','my_remove_admin_menus' );// Removes from post and pagesfunctionremove_comment_support() {remove_post_type_support('post','comments' );remove_post_type_support('page','comments' );}add_action('init','remove_comment_support',100 );// Removes from admin barfunctionmytheme_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

/** * Change Media Gallery URL */if (empty(get_option('upload_url_path' ) ) ) {update_option('upload_url_path','http://assets.website.com/wp-content/uploads' );}

/** * Change Media Gallery URL */add_filter('pre_option_upload_url_path',function() {return'http://assets.website.com/wp-content/uploads';});

Create Custom Thumbnail Size

/** * Create custom thumbnail size */add_image_size('custom-thumbnail',250,250,true );

$thumb =wp_get_attachment_image_src(get_post_thumbnail_id($post->ID),'custom-thumbnail' );echo$thumb[0];

the_post_thumbnail_url($size );

Add Categories for Attachments

/** * Add categories for attachments */functionadd_categories_for_attachments() {register_taxonomy_for_object_type('category','attachment' );}add_action('init' ,'add_categories_for_attachments' );

Add Tags for Attachments

/** * Add tags for attachments */functionadd_tags_for_attachments() {register_taxonomy_for_object_type('post_tag','attachment' );}add_action('init' ,'add_tags_for_attachments' );

Add Custom Excerpt to Pages

/** * Add custom excerpt to pages */functionadd_page_excerpt() {add_post_type_support('page',array('excerpt' ) );}add_action('init','add_page_excerpt' );

Create a Global String

/** * Create a global string */functionglobal_string() {return'String';}

echoglobal_string();

Support Featured Images

/** * Support featured images */add_theme_support('post-thumbnails' );

Support Search Form

/** * Support search form */add_theme_support('html5',array('search-form' ) );

Excluding Pages From Search

/** * Excluding pages from search */functionexclude_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

/** * Disable xmlrpc.php */add_filter('xmlrpc_enabled','__return_false' );remove_action('wp_head','rsd_link' );remove_action('wp_head','wlwmanifest_link' );

Escape HTML in Posts

/** * Escape HTML in <code> or <pre><code> tags. */functionescapeHTML($arr) {if (version_compare(PHP_VERSION,'5.2.3') >=0) {$output =htmlspecialchars($arr[2],ENT_NOQUOTES,get_bloginfo('charset'),false);    }else {$specialChars =array('&' =>'&amp;','<' =>'&lt;','>' =>'&gt;'        );// 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];    }}functionfilterCode($data) {// Uncomment if you want to escape anything within a <pre> tag//$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 );

Create Custom Global Settings

/** * Create custom global settings */functioncustom_settings_page() {?>    <div>    <h1>Custom Settings</h1>    <form method="post" action="options.php"><?phpsettings_fields('section' );do_settings_sections('theme-options' );submit_button();?>    </form>    </div><?php }functioncustom_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 settingfunctionsetting_twitter() {?>    <input type="text" name="twitter" value="<?phpechoget_option('twitter');?>" /><?php }functioncustom_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' );

echoget_option('twitter' );

Remove WordPress Admin Bar

/** * Remove WordPress admin bar */functionremove_admin_bar() {remove_action('wp_head','_admin_bar_bump_cb' );}add_action('get_header','remove_admin_bar' );

Add Open Graph Meta Tags

/** * Add Open Graph Meta Tags */functionmeta_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('/[\n\r\t ]+/',$excerpt, -1,PREG_SPLIT_NO_EMPTY );array_pop($excerptwords );$excerpt =implode('',$excerptwords ) .$excerpt_more;?><meta name="author" content="Your Name"><meta name="description" content="<?phpecho$excerpt;?>"><meta property="og:title" content="<?phpechothe_title();?>"><meta property="og:description" content="<?phpecho$excerpt;?>"><meta property="og:type" content="article"><meta property="og:url" content="<?phpechothe_permalink();?>"><meta property="og:site_name" content="Your Site Name"><meta property="og:image" content="<?phpecho$img_src[0];?>"><?php    }else {return;    }}add_action('wp_head','meta_og',5);

Add Custom Post Type

/** * Add custom post type */functioncreate_custom_post() {register_post_type('custom-post',// slug for custom post typearray('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

/** * Implement preconnect to Google Fonts in themes */functiontwentyfifteen_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 stringif (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 thumbnail column to post listing */add_image_size('admin-list-thumb',80,80,false );functionwpcs_add_thumbnail_columns($columns ) {if ( !is_array($columns ) )$columns =array();$new =array();foreach($columnsas$key =>$title ) {if ($key =='title' )// Put the Thumbnail column before the Title column$new['featured_thumb'] =__('Image');$new[$key] =$title;    }return$new;}functionwpcs_add_thumbnail_columns_data($column,$post_id ) {switch ($column ) {case'featured_thumb':echo'<a href="' .$post_id .'">';echothe_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

/** * Add lead class to first paragraph */functionfirst_paragraph($content ) {returnpreg_replace('/<p([^>]+)?>/','<p$1>',$content,1 );}add_filter('the_content','first_paragraph' );

Exclude Custom Post Type from Search

/** * Exclude custom post type from search */functionexcludePages($query ) {if ($query->is_search ) {$query->set('post_type','post' );}return$query;}add_filter('pre_get_posts','excludePages' );

Remove Query String from Static Resources

/** * Remove query string from static resources */functionremove_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

/** * Modify jQuery */functionmodify_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

/** * Disable website field from comment form */functiondisable_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

/** * Disable JSON REST API */add_filter('json_enabled','__return_false');add_filter('json_jsonp_enabled','__return_false');

Switch Post Type

/** * Switch post type */functionswitch_post_type ($old_post_type,$new_post_type ) {global$wpdb;// Run the update query$wpdb->update($wpdb->posts,// Setarray('post_type' =>$new_post_type),// Wherearray('post_type' =>$old_post_type )    );}

PHP Logger

/** * PHP Logger */functionphp_logger($data ) {$output =$data;if (is_array($output ) )$output =implode(',',$output );// print the result into the JavaScript consoleecho"<script>console.log( 'PHP LOG:" .$output ."' );</script>";}

Always Show Second Bar in TinyMCE

/** * Always show second bar in TinyMCE */functionshow_tinymce_toolbar($in ) {$in['wordpress_adv_hidden'] =false;return$in;}add_filter('tiny_mce_before_init','show_tinymce_toolbar' );

Remove Admin Menu Items Depending on User Role

/** * Clone the administrator user role */functionclone_admin_role() {global$wp_roles;if ( !isset($wp_roles ) )$wp_roles =newWP_Roles();$adm =$wp_roles->get_role('administrator' );// Add new "Client" role with all admin capabilities$wp_roles->add_role('client','Client',$adm->capabilities );}add_action('init','clone_admin_role' );/** * Specify which admin menu items are visible for users with role "Client" */functionremove_dashboard_menus() {if (current_user_can('client' ) ) {// Hide Updates under Dashboard menuremove_submenu_page('index.php','update-core.php' );// Hide Commentsremove_menu_page('edit-comments.php' );// Hide Pluginsremove_menu_page('plugins.php' );// Hide Themes, Customizer and Widgets under Appearance menuremove_submenu_page('themes.php','themes.php' );remove_submenu_page('themes.php','customize.php?return=' .urlencode($_SERVER['REQUEST_URI'] ) );remove_submenu_page('themes.php','widgets.php' );// Hide Toolsremove_menu_page('tools.php' );// Hide General Settingsremove_menu_page('options-general.php' );    }}add_action('admin_menu','remove_dashboard_menus' );

Remove Admin Menu Items Depending on Email Address (domain)

/** * Specify which users can see admin menu items based on their email address */functionremove_dashboard_menus() {$user_data =get_userdata(get_current_user_id() );$user_email =isset($user_data->user_email ) ?$user_data->user_email :'';if ( !strpos($user_email,'@yourcompany.com' ) ) {// Hide Updates under Dashboard menuremove_submenu_page('index.php','update-core.php' );// Hide Commentsremove_menu_page('edit-comments.php' );// Hide Pluginsremove_menu_page('plugins.php' );// Hide Themes, Customizer and Widgets under Appearance menuremove_submenu_page('themes.php','themes.php' );remove_submenu_page('themes.php','customize.php?return=' .urlencode($_SERVER['REQUEST_URI'] ) );remove_submenu_page('themes.php','widgets.php' );// Hide Toolsremove_menu_page('tools.php' );// Hide General Settingsremove_menu_page('options-general.php' );    }}add_action('admin_menu','remove_dashboard_menus' );

Reorder Admin Menu Items

/** * Reorder admin menu */functioncustom_menu_order($menu_ord ) {if ( !$menu_ord ) {returntrue; }returnarray('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 WordPress Loops

/** * Exclude a category from all WordPress loops */add_action('pre_get_posts',function($query ) {// anonymous callbackglobal$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 );    }});

Disable the message - JQMIGRATE: Migrate is installed, version 1.4.1

add_action('wp_default_scripts',function ($scripts) {if (!empty($scripts->registered['jquery'])) {$scripts->registered['jquery']->deps =array_diff($scripts->registered['jquery']->deps, ['jquery-migrate']);    }});

Load heavy 3rd-party scripts later for better performance

<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>