has_action() – Function | Developer.WordPress.org

Checks if any action has been registered for a hook.

Description

When using the $callback argument, this function may return a non-boolean value that evaluates to false (e.g. 0), so use the === operator for testing the return value.

Parameters

$hook_namestringrequired: The name of the action hook.
$callbackcallable|string|array|falseoptional: The callback to check for.
This function can be called unconditionally to speculatively check a callback that may or may not exist.
Default:false

bool|int If $callback is omitted, returns boolean for whether the hook has anything registered. When checking a specific function, the priority of that hook is returned, or false if the function is not attached.

More Information

Since this action is an alias of has_filter() , it also uses the global array $wp_filter that stores all of the filters / actions.

Source

function has_action( $hook_name, $callback = false ) {	return has_filter( $hook_name, $callback ); }

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Uses	Description
has_filter()`wp-includes/plugin.php`	Checks if any filter has been registered for a hook.

Used by	Description
wp_enqueue_emoji_styles()`wp-includes/formatting.php`	Enqueues the important emoji-related styles.
wp_enqueue_admin_bar_bump_styles()`wp-includes/admin-bar.php`	Enqueues inline bump styles to make room for the admin bar.
wp_enqueue_admin_bar_header_styles()`wp-includes/admin-bar.php`	Enqueues inline style to hide the admin bar when printing.
wp_enqueue_embed_styles()`wp-includes/embed.php`	Enqueues the CSS in the embed iframe header.
wp_enqueue_block_template_skip_link()`wp-includes/theme-templates.php`	Enqueues the skip-link script & styles.
wp_save_post_revision_on_insert()`wp-includes/revision.php`	Saves revisions for a post after all changes have been made.
_wp_get_iframed_editor_assets()`wp-includes/block-editor.php`	Collect the block editor assets that need to be loaded into the editor’s iframe.
wp_maybe_enqueue_oembed_host_js()`wp-includes/embed.php`	Enqueue the wp-embed script if the provided oEmbed HTML contains a post embed.
wp_is_local_html_output()`wp-includes/https-detection.php`	Checks whether a given HTML string is likely an output from this WordPress site.
wp_insert_site()`wp-includes/ms-site.php`	Inserts a new site into the database.
WP_Customize_Manager::save_changeset_post()`wp-includes/class-wp-customize-manager.php`	Saves the post for the loaded changeset.
do_action_deprecated()`wp-includes/plugin.php`	Fires functions attached to a deprecated action hook.
WP_Screen::render_meta_boxes_preferences()`wp-admin/includes/class-wp-screen.php`	Renders the meta boxes preferences.
wp_admin_bar_customize_menu()`wp-includes/admin-bar.php`	Adds the “Customize” link to the Toolbar.
display_setup_form()`wp-admin/install.php`	Displays installer setup form.
get_plugin_page_hook()`wp-admin/includes/plugin.php`	Gets the hook attached to the administrative page of a plugin.
do_feed()`wp-includes/functions.php`	Loads the feed template from the use of an action hook.
WP_Customize_Setting::preview()`wp-includes/class-wp-customize-setting.php`	Add filters to supply the setting’s value when accessed.
WP_Customize_Setting::update()`wp-includes/class-wp-customize-setting.php`	Save the value of the setting, using the related API.
wp_save_post_revision()`wp-includes/revision.php`	Creates a revision for the current version of a post.
comment_form()`wp-includes/comment-template.php`	Outputs a complete commenting form for use within a template.

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Changelog

Version	Description
2.5.0	Introduced.

has_action( string $hook_name, callable|string|array|false $callback = false ): bool|int

In this article

Description

See also

Parameters

Return

More Information

Source

Changelog

User Contributed Notes