do_action( string $hook_name, mixed $arg )

Calls the callback functions that have been added to an action hook.

Description

This function invokes all functions attached to action hook $hook_name.
It is possible to create new action hooks by simply calling this function, specifying the name of the new hook using the $hook_name parameter.

You can pass extra arguments to the hooks, much like you can with apply_filters().

Example usage:

// The action callback function.
function example_callback( $arg1, $arg2 ) {
    // (maybe) do something with the args.
}
add_action( 'example_action', 'example_callback', 10, 2 );

/*
 * Trigger the actions by calling the 'example_callback()' function
 * that's hooked onto `example_action` above.
 *
 * - 'example_action' is the action hook.
 * - $arg1 and $arg2 are the additional arguments passed to the callback.
do_action( 'example_action', $arg1, $arg2 );

Parameters

$hook_name

(Required) The name of the action to be executed.

$arg

(Optional) Additional arguments which are passed on to the functions hooked to the action. Default empty.

Source

File: wp-includes/plugin.php 

function do_action($tag, $arg = '') {
	global $wp_filter, $wp_actions, $wp_current_filter;

	if ( ! isset($wp_actions[$tag]) )
		$wp_actions[$tag] = 1;
	else
		++$wp_actions[$tag];

	$all_args = func_get_args();

	// Do 'all' actions first
	if ( isset($wp_filter['all']) ) {
		$wp_current_filter[] = $tag;
		_wp_call_all_hook( $all_args );
	}

	if ( !isset($wp_filter[$tag]) ) {
		if ( isset($wp_filter['all']) )
			array_pop($wp_current_filter);
		return;
	}

	if ( !isset($wp_filter['all']) )
		$wp_current_filter[] = $tag;

	$args = $all_args;
	array_shift( $args );

	if ( empty( $args ) ) {
		$args = array( '' );
	}

	$wp_filter[ $tag ]->do_action( $args );

	array_pop($wp_current_filter);
}

Expand Source Code View on GitHub

Related

Uses

Uses
Uses Description
wp-includes/plugin.php: _wp_call_all_hook()

Calls the ‘all’ hook, which will process the functions hooked into it.

Used By

Used By
Used By Description
wp-admin/includes/class-wp-application-passwords-list-table.php: WP_Application_Passwords_List_Table::print_js_template_row()

Prints the JavaScript template for the new row item.
wp-admin/includes/class-wp-application-passwords-list-table.php: WP_Application_Passwords_List_Table::column_default()

Generates content for a single row of the table
wp-admin/includes/class-wp-ms-sites-list-table.php: WP_MS_Sites_List_Table::extra_tablenav()

Extra controls to be displayed between bulk actions and pagination.
wp-admin/includes/meta-boxes.php: register_and_do_post_meta_boxes()

Registers the default post meta boxes, and runs the do_meta_boxes actions.
wp-includes/classicpress/class-wp-compat.php: WP_Compat::using_block_function()

This function have to be called from a polyfill to map themes and plugins calling those functions.
wp-includes/sitemaps.php: wp_sitemaps_get_server()

Retrieves the current Sitemaps server instance.
wp-includes/rest-api/endpoints/class-wp-rest-sidebars-controller.php: WP_REST_Sidebars_Controller::update_item()

Updates a sidebar.
wp-includes/rest-api/endpoints/class-wp-rest-menus-controller.php: WP_REST_Menus_Controller::create_item()

Creates a single term in a taxonomy.
wp-includes/rest-api/endpoints/class-wp-rest-menus-controller.php: WP_REST_Menus_Controller::update_item()

Updates a single term from a taxonomy.
wp-includes/rest-api/endpoints/class-wp-rest-menus-controller.php: WP_REST_Menus_Controller::delete_item()

Deletes a single term from a taxonomy.
wp-includes/rest-api/endpoints/class-wp-rest-menus-controller.php: WP_REST_Menus_Controller::handle_auto_add()

Updates the menu’s auto add from a REST request.
wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php: WP_REST_Autosaves_Controller::create_post_autosave()

Creates autosave for the specified post.
wp-includes/rest-api/endpoints/class-wp-rest-application-passwords-controller.php: WP_REST_Application_Passwords_Controller::create_item()

Creates an application password.
wp-includes/rest-api/endpoints/class-wp-rest-application-passwords-controller.php: WP_REST_Application_Passwords_Controller::update_item()

Updates an application password.
wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php: WP_REST_Menu_Items_Controller::delete_item()

Deletes a single menu item.
wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php: WP_REST_Menu_Items_Controller::create_item()

Creates a single post.
wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php: WP_REST_Menu_Items_Controller::update_item()

Updates a single nav menu item.
wp-includes/object-relationships.php: cp_object_relationship_exists()

Check if a relationship exists between two recognized objects.
wp-includes/object-relationships.php: cp_add_object_relationship()

Create a relationship between two recognized objects.
wp-includes/object-relationships.php: cp_delete_object_relationship()

Delete a relationship between two recognized objects.
wp-includes/ms-site.php: wp_maybe_transition_site_statuses_on_update()

Triggers actions on site status updates.
wp-includes/ms-site.php: wp_prepare_site_data()

Prepares site data for insertion or update in the database.
wp-includes/ms-site.php: wp_insert_site()

Inserts a new site into the database.
wp-includes/ms-site.php: wp_update_site()

Updates a site in the database.
wp-includes/ms-site.php: wp_delete_site()

Deletes a site from the database.
wp-includes/general-template.php: wp_body_open()

Fires the wp_body_open action.
wp-signup.php: confirm_user_signup()

Shows a message confirming that the new user has been registered and is awaiting activation.
wp-signup.php: signup_blog()

Shows a form for a user or visitor to sign up for a new site.
wp-signup.php: confirm_blog_signup()

Shows a message confirming that the new site has been registered and is awaiting activation.
wp-signup.php: do_signup_header()

Prints signup_header via wp_head.
wp-signup.php: show_blog_form()

Generates and displays the Sign-up and Create Site forms.
wp-signup.php: show_user_form()

Displays the fields for the new user account registration form.
wp-signup.php: signup_another_blog()

Shows a form for returning users to sign up for another site.
wp-signup.php: confirm_another_blog_signup()

Shows a message confirming that the new site has been created.
wp-signup.php: signup_user()

Shows a form for a visitor to sign up for a new user account.
wp-login.php: login_header()

Output the login page header.
wp-login.php: login_footer()

Outputs the footer for the login page.
wp-includes/customize/class-wp-customize-nav-menu-item-control.php: WP_Customize_Nav_Menu_Item_Control::content_template()

JS/Underscore template for the control UI.
wp-includes/general-template.php: wp_enqueue_code_editor()

Enqueues assets needed by the code editor for the given settings.
wp-includes/general-template.php: wp_head()

Fires the wp_head action.
wp-includes/general-template.php: wp_footer()

Fires the wp_footer action.
wp-includes/general-template.php: wp_meta()

Theme container function for the ‘wp_meta’ action.
wp-includes/general-template.php: get_header()

Loads header template.
wp-includes/general-template.php: get_footer()

Loads footer template.
wp-includes/general-template.php: get_sidebar()

Loads sidebar template.
wp-includes/general-template.php: get_template_part()

Loads a template part into a template.
wp-includes/general-template.php: get_search_form()

Displays search form.
wp-includes/script-loader.php: wp_print_footer_scripts()

Hooks to print the scripts and styles in the footer.
wp-includes/script-loader.php: wp_enqueue_scripts()

Wrapper for do_action( ‘wp_enqueue_scripts’ ).
wp-includes/script-loader.php: wp_print_head_scripts()

Prints the script queue in the HTML head on the front end.
wp-includes/script-loader.php: print_head_scripts()

Prints the script queue in the HTML head on admin pages.
wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php: WP_REST_Comments_Controller::create_item()

Creates a comment.
wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php: WP_REST_Comments_Controller::update_item()

Updates a comment.
wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php: WP_REST_Comments_Controller::delete_item()

Deletes a comment.
wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php: WP_REST_Users_Controller::create_item()

Creates a single user.
wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php: WP_REST_Users_Controller::update_item()

Updates a single user.
wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php: WP_REST_Users_Controller::delete_item()

Deletes a single user.
wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php: WP_REST_Terms_Controller::create_item()

Creates a single term in a taxonomy.
wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php: WP_REST_Terms_Controller::update_item()

Updates a single term from a taxonomy.
wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php: WP_REST_Terms_Controller::delete_item()

Deletes a single term from a taxonomy.
wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php: WP_REST_Revisions_Controller::delete_item()

Deletes a single revision.
wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php: WP_REST_Posts_Controller::create_item()

Creates a single post.
wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php: WP_REST_Posts_Controller::update_item()

Updates a single post.
wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php: WP_REST_Posts_Controller::delete_item()

Deletes a single post.
wp-includes/functions.wp-styles.php: wp_print_styles()

Displays styles that are in the $handles queue.
wp-includes/template.php: load_template()

Requires the template file with WordPress environment.
wp-includes/media-template.php: wp_print_media_templates()

Prints the templates used in the media manager.
wp-includes/nav-menu.php: wp_delete_nav_menu()

Deletes a navigation menu.
wp-includes/nav-menu.php: wp_update_nav_menu_object()

Saves the properties of a menu or create a new menu with those properties.
wp-includes/nav-menu.php: wp_update_nav_menu_item()

Saves the properties of a menu item or create a new one.
wp-includes/embed.php: enqueue_embed_scripts()

Enqueues embed iframe default CSS and JS.
wp-includes/ms-load.php: ms_load_current_site_and_network()

Identifies the network and site of a requested domain and path and populates the corresponding network and site global objects as part of the multisite bootstrap process.
wp-includes/capabilities.php: grant_super_admin()

Grants Super Admin privileges.
wp-includes/capabilities.php: revoke_super_admin()

Revokes Super Admin privileges.
wp-includes/functions.wp-scripts.php: wp_print_scripts()

Prints scripts in document head that are in the $handles queue.
wp-includes/ms-network.php: clean_network_cache()

Removes a network from the object cache.
wp-includes/ms-blogs.php: switch_to_blog()

Switches the current blog.
wp-includes/ms-blogs.php: restore_current_blog()

Restores the current blog, after calling switch_to_blog().
wp-includes/ms-site.php: clean_blog_cache()

Clean the blog cache
wp-includes/ms-blogs.php: wpmu_update_blogs_date()

Updates the last_updated field for the current site.
wp-includes/meta.php: update_metadata_by_mid()

Updates metadata by meta ID.
wp-includes/meta.php: delete_metadata_by_mid()

Deletes metadata by meta ID.
wp-includes/meta.php: add_metadata()

Adds metadata for the specified object.
wp-includes/meta.php: update_metadata()

Updates metadata for the specified object. If no value already exists for the specified object ID and metadata key, the metadata will be added.
wp-includes/meta.php: delete_metadata()

Deletes metadata for the specified object.
wp-includes/theme.php: check_theme_switched()

Checks if a theme has been changed and runs ‘after_switch_theme’ hook on the next WP load.
wp-includes/theme.php: _wp_customize_publish_changeset()

Publishes a snapshot’s changes.
wp-includes/theme.php: switch_theme()

Switches the theme.
wp-includes/post-thumbnail-template.php: get_the_post_thumbnail()

Retrieves the post thumbnail.
wp-includes/ms-functions.php: add_existing_user_to_blog()

Adds a user to a blog based on details from maybe_add_existing_user_to_blog().
wp-includes/ms-functions.php: wpmu_signup_blog()

Records site signup information for future activation.
wp-includes/ms-functions.php: wpmu_signup_user()

Records user signup information for future activation.
wp-includes/ms-functions.php: wpmu_activate_signup()

Activates a signup.
wp-includes/ms-functions.php: wpmu_create_user()

Creates a user.
wp-includes/ms-functions.php: add_user_to_blog()

Adds a user to a blog, along with specifying the user’s role.
wp-includes/ms-functions.php: remove_user_from_blog()

Removes a user from a blog.
wp-admin/includes/class-wp-media-list-table.php: WP_Media_List_Table::column_default()

Handles output for the default column.
wp-admin/includes/class-wp-media-list-table.php: WP_Media_List_Table::extra_tablenav()
wp-admin/includes/class-wp-plugins-list-table.php: WP_Plugins_List_Table::single_row()
wp-admin/includes/class-wp-ms-themes-list-table.php: WP_MS_Themes_List_Table::column_default()

Handles default column output.
wp-admin/includes/class-wp-ms-themes-list-table.php: WP_MS_Themes_List_Table::single_row()
wp-admin/includes/class-wp-comments-list-table.php: WP_Comments_List_Table::extra_tablenav()
wp-admin/includes/class-wp-comments-list-table.php: WP_Comments_List_Table::column_default()
wp-admin/includes/schema.php: populate_options()

Create WordPress options and set the default values.
wp-admin/includes/nav-menu.php: wp_nav_menu_update_menu_items()

Saves nav menu items.
wp-admin/includes/class-theme-upgrader.php: Theme_Upgrader::install()

Install a theme package.
wp-admin/includes/class-theme-upgrader.php: Theme_Upgrader::bulk_upgrade()

Upgrade several themes at once.
wp-admin/includes/class-wp-links-list-table.php: WP_Links_List_Table::column_default()

Handles the default column output.
wp-admin/includes/class-core-upgrader.php: Core_Upgrader::upgrade()

Upgrade ClassicPress core.
wp-admin/includes/bookmark.php: wp_delete_link()

Deletes a specified link from the database.
wp-admin/includes/bookmark.php: wp_insert_link()

Inserts a link into the database, or updates an existing link.
wp-admin/includes/class-wp-plugin-install-list-table.php: WP_Plugin_Install_List_Table::display_tablenav()
wp-admin/includes/meta-boxes.php: page_attributes_meta_box()

Displays page attributes form fields.
wp-admin/includes/meta-boxes.php: link_submit_meta_box()

Displays link create form fields.
wp-admin/includes/meta-boxes.php: post_submit_meta_box()

Displays post submit form fields.
wp-admin/includes/meta-boxes.php: attachment_submit_meta_box()

Displays attachment submit form fields.
wp-admin/includes/meta-boxes.php: post_comment_status_meta_box()

Displays comments status form fields.
wp-admin/includes/update-core.php: update_core()

Upgrades the core of ClassicPress.
wp-admin/includes/class-wp-privacy-requests-table.php: WP_Privacy_Requests_Table::column_default()

Default column handler.
wp-admin/includes/privacy-tools.php: wp_privacy_process_personal_data_erasure_page()

Mark erasure requests as completed after processing is finished.
wp-admin/includes/theme.php: delete_theme()

Removes a theme.
wp-admin/includes/plugin.php: activate_plugin()

Attempts activation of plugin in a “sandbox” and redirects on success.
wp-admin/includes/plugin.php: deactivate_plugins()

Deactivates a single plugin or multiple plugins.
wp-admin/includes/plugin.php: delete_plugins()

Removes directory and files of a plugin for a list of plugins.
wp-admin/includes/plugin.php: uninstall_plugin()

Uninstalls a single plugin.
wp-admin/includes/class-wp-ms-sites-list-table.php: WP_MS_Sites_List_Table::column_plugins()

Handles the plugins column output.
wp-admin/includes/class-wp-ms-sites-list-table.php: WP_MS_Sites_List_Table::column_default()

Handles output for the default column.
wp-admin/includes/privacy-tools.php: wp_privacy_generate_personal_data_export_file()

Generate the personal data export file.
wp-admin/includes/privacy-tools.php: wp_privacy_process_personal_data_export_page()

Intercept personal data exporter page Ajax responses in order to assemble the personal data export file.
wp-admin/includes/class-language-pack-upgrader.php: Language_Pack_Upgrader::bulk_upgrade()

Bulk upgrade language packs.
wp-admin/includes/class-wp-theme-install-list-table.php: WP_Theme_Install_List_Table::display()

Displays the theme install table.
wp-admin/includes/update.php: wp_plugin_update_row()

Displays update information for a plugin.
wp-admin/includes/update.php: wp_theme_update_row()

Displays update information for a theme.
wp-admin/includes/class-plugin-upgrader.php: Plugin_Upgrader::bulk_upgrade()

Bulk upgrade several plugins at once.
wp-admin/includes/class-plugin-upgrader.php: Plugin_Upgrader::install()

Install a plugin package.
wp-admin/includes/ms.php: confirm_delete_users()
wp-includes/ms-deprecated.php: update_user_status()

Update the status of a user in the database.
wp-admin/includes/ms.php: wpmu_delete_user()

Deletes a user from the network and remove from all sites.
wp-admin/install.php: display_setup_form()

Displays installer setup form.
wp-activate.php: do_activate_header()

Adds an action hook specific to this page.
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Changelog

Changelog
Version Description
5.3.0 Formalized the existing and already documented ...$arg parameter by adding it to the function signature.
1.2.0 Introduced.