Hooks

A lightweight & efficient EventManager for JavaScript.

Installation

Install the module

npm install @wordpress/hooks --save

This package assumes that your code will run in an ES2015+ environment. If you're using an environment that has limited or no support for ES2015+ such as lower versions of IE then using core-js or @babel/polyfill will add support for these methods. Learn more about it in Babel docs.

Usage

In your JavaScript project, use hooks as follows:

import { createHooks } from '@wordpress/hooks';

myObject.hooks = createHooks();
myObject.hooks.addAction(); //etc...

In the WordPress context, API functions can be called via the global wp.hooks like this wp.hooks.addAction(), etc. One notable difference from the PHP API is that addAction() and addFilter() also need to include a namespace as the second argument.

API Usage

• createHooks()
• addAction( 'hookName', 'namespace', callback, priority )
• addFilter( 'hookName', 'namespace', callback, priority )
• removeAction( 'hookName', 'namespace' )
• removeFilter( 'hookName', 'namespace' )
• removeAllActions( 'hookName' )
• removeAllFilters( 'hookName' )
• doAction( 'hookName', arg1, arg2, moreArgs, finalArg )
• applyFilters( 'hookName', content, arg1, arg2, moreArgs, finalArg )
• doingAction( 'hookName' )
• doingFilter( 'hookName' )
• didAction( 'hookName' )
• didFilter( 'hookName' )
• hasAction( 'hookName', 'namespace' )
• hasFilter( 'hookName', 'namespace' )
• actions
• filters

Events on action/filter add or remove

Whenever an action or filter is added or removed, a matching hookAdded or hookRemoved action is triggered.

• hookAdded action is triggered when addFilter() or addAction() method is called, passing values for hookName, functionName, callback and priority.
• hookRemoved action is triggered when removeFilter() or removeAction() method is called, passing values for hookName and functionName.

The all hook

In non-minified builds developers can register a filter or action that will be called on all hooks, for example: addAction( 'all', 'namespace', callbackFunction );. Useful for debugging, the code supporting the all hook is stripped from the production code for performance reasons.