has_action( string $hook_name, callable|false $callback = false )

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.

See also

Parameters

$hook_name

(string) (Required) The name of the action hook.

$callback

(callable|false) (Optional) The callback to check for.

Default value: false

Return

(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

File: wp-includes/plugin.php 

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

Uses

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

Checks if any filter has been registered for a hook.

Used By

Used By Description
wp-includes/https-detection.php: wp_is_local_html_output()

Checks whether a given HTML string is likely an output from this WordPress site.
wp-includes/ms-site.php: wp_insert_site()

Inserts a new site into the database.
wp-includes/class-wp-customize-manager.php: WP_Customize_Manager::save_changeset_post()

Save the post for the loaded changeset.
wp-includes/plugin.php: do_action_deprecated()

Fires functions attached to a deprecated action hook.
wp-admin/includes/class-wp-screen.php: WP_Screen::render_meta_boxes_preferences()

Render the meta boxes preferences.
wp-admin/install.php: display_setup_form()

Display installer setup form.
wp-admin/includes/plugin.php: get_plugin_page_hook()

Gets the hook attached to the administrative page of a plugin.
wp-includes/functions.php: do_feed()

Load the feed template from the use of an action hook.
wp-includes/class-wp-customize-setting.php: WP_Customize_Setting::preview()

Add filters to supply the setting’s value when accessed.
wp-includes/class-wp-customize-setting.php: WP_Customize_Setting::update()

Save the value of the setting, using the related API.
wp-includes/comment-template.php: comment_form()

Outputs a complete commenting form for use within a template.

Changelog

Version Description
2.5.0 Introduced.

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Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/has_action