• wp_head Action Hook:

    • Description: Used to inject code into the <head> section of the HTML document.
    • Example:
       
      function custom_code_in_head() { echo '<meta name="description" content="Custom description">'; } add_action('wp_head', 'custom_code_in_head');

  • wp_footer Action Hook:

    • Description: Allows insertion of code just before the closing </body> tag.
    • Example:
       
      function custom_code_in_footer()
      { echo '<script>alert("Hello, World!");</script>'; }
       
      add_action('wp_footer', 'custom_code_in_footer');

  • init Action Hook:

    • Description: Used for initializing code or actions.
    • Example:
       
      function custom_init_function() { // Your initialization code here } add_action('init', 'custom_init_function');

 

2. Filter Hooks:

the_content Filter Hook:

 

    • Description: Allows modification of the content before it is displayed.
    • Example:
       
      function custom_content_filter($content) { return $content . '<p>Custom content added.</p>'; }
      add_filter('the_content', 'custom_content_filter');

  • the_title Filter Hook:

    • Description: Used to modify the post/page title before it is displayed.
    • Example:
      function custom_title_filter($title)
      { return 'Custom Prefix: ' . $title; }
      add_filter('the_title', 'custom_title_filter');

  • excerpt_length Filter Hook:

    • Description: Adjusts the length of the excerpt.
    • Example:
      function custom_excerpt_length($length)
      { return 20; // Set the desired length }
      add_filter('excerpt_length', 'custom_excerpt_length');

admin_menu Action Hook:

  • Description: Used to add menu items to the WordPress admin menu.
  • Example:
    function add_custom_menu()
    { add_menu_page('Custom Page', 'Custom Menu', 'manage_options', 'custom-page', 'custom_page_callback'); }
    add_action('admin_menu', 'add_custom_menu'); function custom_page_callback() { // Content for the custom admin page }

    widgets_init Action Hook:

    • Description: Enables the registration of custom widgets.
    • Example:
      function register_custom_widget() { register_widget('Custom_Widget_Class'); }
      add_action('widgets_init', 'register_custom_widget'); class Custom_Widget_Class extends WP_Widget
      { // Custom widget implementation }

    the_excerpt Filter Hook:

    • Description: Modifies the excerpt content before it is displayed.
    • Example:
      function custom_excerpt_filter($excerpt)
      {
      return $excerpt . ' <a href="' . get_permalink() . '">Read more</a>';
      }
      add_filter('the_excerpt', 'custom_excerpt_filter');
     
     
     

    login_headerurl Filter Hook:

    • Description: Modifies the login page header URL.
    • Example:
    • function custom_login_url() {
          return home_url('/');
      }
      add_filter('login_headerurl', 'custom_login_url');
     
     

    wp_nav_menu_items Filter Hook:

    • Description: Adds custom items to the navigation menu.
    • Example:
    • function add_custom_menu_item($items, $args) {
          if ($args->theme_location == 'primary') {
              $items .= '<li><a href="#">Custom Link</a></li>';
          }
          return $items;
      }
      add_filter('wp_nav_menu_items', 'add_custom_menu_item', 10, 2);

    • save_post Action Hook:

      • Description: Triggered after a post or page is saved in the database.
      • Example:
      • function custom_save_post_callback($post_id, $post, $update) {
            // Custom logic to be executed after post/page is saved
        }
        add_action('save_post', 'custom_save_post_callback', 10, 3);

      wp_enqueue_scripts Action Hook:

      • Description: Used to enqueue scripts and styles on the front end.
      • Example:
      • function enqueue_custom_scripts() {
            wp_enqueue_script('custom-script', get_template_directory_uri() . '/js/custom-script.js', array('jquery'), '1.0', true);
        }
        add_action('wp_enqueue_scripts', 'enqueue_custom_scripts');

      • the_title Filter Hook:

        • Description: Modifies the post or page title before it is displayed.
        • Example:
        • function custom_title_filter($title) {
              return 'Custom Prefix: ' . $title;
          }
          add_filter('the_title', 'custom_title_filter');

      excerpt_length Filter Hook:

      • Description: Modifies the number of words in the excerpt.
      • Example:
      • function custom_excerpt_length($length)
      • { return 20; // Set the custom excerpt length }
      • add_filter('excerpt_length', 'custom_excerpt_length');

      body_class Filter Hook:

      • Description: Adds custom classes to the body element.
      • Example:function add_custom_body_class($classes) {
            $classes[] = 'custom-class';
            return $classes;
        }
        add_filter('body_class', 'add_custom_body_class');