Try to see the function with better names: apply_filters( $filter_name, // used for add_filter( $filter_name, ‘callback’ ); $value_to_change, // the only variable whose value you can change $context_1, // context $context_2 // more context ); So when that function is called as: // wp-login.php line 94 apply_filters( ‘login_body_class’, $classes, $action ); You can use … … Read more
Overview Basically the “Plugin API,” which summons Filters and Hooks, consists out of the following functions: apply_filters() – execute do_action – execute apply_filters_ref_array() – execute do_action_ref_array() – execute add_filter() – add to stack add_action() – add to stack Basic Internals Overall there’re a couple of globals (what else in WordPress world) involved: global $wp_filter, $wp_actions, … Read more
QUESTION AND ANSWER REVISITED There are sometimes these questions that nags you and hunts you down later in life again, and this is one such question. This question had me thinking about an alternative solution to the problem. As I already stated, custom fields and meta boxes are there to store small pieces of meta … Read more
It is easier to read: When is what called? If you are debugging a hook you can immediately see if you have to read the function or not: If it is not your hook, you can skip the code. In my themes and plugins I combine all registrations for actions, filters and shortcodes at the … Read more
As of WordPress 4.1 there is a filter: script_loader_tag. You can use it to find the correct script: add_filter( ‘script_loader_tag’, function ( $tag, $handle ) { if ( ‘contact-form-7’ !== $handle ) return $tag; return str_replace( ‘ src’, ‘ defer=”defer” src’, $tag ); }, 10, 2 ); Old answer There is no dedicated filter available … Read more
Just use the the_content filter, e.g.: <?php function theme_slug_filter_the_content( $content ) { $custom_content=”YOUR CONTENT GOES HERE”; $custom_content .= $content; return $custom_content; } add_filter( ‘the_content’, ‘theme_slug_filter_the_content’ ); ?> Basically, you append the post content after your custom content, then return the result. Edit As Franky @bueltge points out in his comment, the process is the same … Read more
That’s a very good question. It goes down to the dark heart of the plugin API and best programming practices. For the following answer I created a simple plugin to illustrate the problem with easy to read code. <?php # -*- coding: utf-8 -*- /* Plugin Name: Anonymous OOP Action */ if ( ! class_exists( … Read more
We will hook into init and remove actions as followed: function disable_wp_emojicons() { // all actions related to emojis 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’ ); // filter to remove TinyMCE emojis add_filter( … Read more