Wordpress Hooks

Register a Custom Menu in the Admin

function register_my_custom_menu_page() {
 add_menu_page( 'custom menu title', 'custom menu', 'manage_options', 'myplugin/myplugin-admin.php', '', 'dashicons-admin-site', 6 );
}
add_action( 'admin_menu', 'register_my_custom_menu_page' );

Change the Excerpt Length

function excerpt_length_example( $words ) {
 return 15;
}
add_filter( 'excerpt_length', 'excerpt_length_example' );

Hook into Post Publishing

function publish_post_tweet($post_ID) {
  global $post;
  // Code to send a tweet with post info
}
add_action('publish_post', 'publish_post_tweet');

Hook Into Widget Initialization

function create_my_widget() {
 register_sidebar(array(
 'name' => __( 'My Sidebar', 'mytheme' ),
 'id' => 'my_sidebar',
 'description' => __( 'The one and only', 'mytheme' ),
 ));
}
add_action( 'widgets_init', 'create_my_widget' );

Hook Into Front-end Scripts and Styles

function theme_styles() {
 wp_enqueue_style( 'bootstrap_css', get_template_directory_uri() . '/css/bootstrap.min.css' );
 wp_enqueue_style( 'main_css', get_template_directory_uri() . '/style.css' );
 wp_enqueue_script( 'bootstrap_js', get_template_directory_uri() . '/js/bootstrap.min.js', array('jquery'), '', true );
 wp_enqueue_script( 'theme_js', get_template_directory_uri() . '/js/theme.js', array('jquery', 'bootstrap_js'), '', true );
}
add_action( 'wp_enqueue_scripts', 'theme_styles' );