WordPress Hooks (Actions and Filters) Search Tool

This started out as a PHP regex experiment. I wanted to find the WordPress “action” hooks in a particular theme so that I can add my own action function to it.

So instead of searching through the whole lot of files for do_actions I sat down writing a regular expression to do this. I was very satisfied with the results which made me think about creating a tool to do this.

So here you go a standalone PHP script which seeps through the PHP code of the WordPress core, plugins, themes or anything you specify and gets you a list of actions and filters.

I use the word “standalone” because this isn’t a WordPress plugin or anything which requires WordPress functions. This is a script which uses a regex in preg_match_all() to find all “tag” names in the do_action() and apply_filters() function. This does not even require WordPress, if you want to find the hooks in a plugin just download the plugin, unzip it to a directory readable by this tool.

Download WordPress Hooks Search Tool | GitHub

Usage

Upload the code to your document root (or anywhere else) and access it from the browser.

http://<yourdomain>/wp-hooks-search.php

Enter the directory or file to search for hooks. It can be either relative or absolute. If a directory is entered all subdirectories are also scanned. If you wish to scan the current directory enter a dot (.) in the text box.

Note: On Windows (WAMP and XAMPP users) you must use forward slash in the path instead of the usual backslash like this

wordpress/wp-content/themes/customizr

The second textbox is optional. If you are searching for a particular name in the hook you can enter it there.

Screenshots

Regular Expression

Even if this tool has 250+ lines of code the hero of this script is the regular expression which hooks out the hooks 😀

/(apply_filters|do_action)\s*\(\s*[\'\"](.+?)\s*[,\)]/

A do_action or an apply_filters function can look like any of the following.

do_action('wp_my_action',$variable);
do_action  ( "wp_head"  );
apply_filters('filter_name',  $value);
apply_filters('filter_' . $variable,  $value);

Here is the anatomy of the regular expression.

(apply_filters|do_action) – Match the word “apply_filters” OR “do_action”

\s* – The \s matches a whitespace character and putting an asterisk (*) in front of it matches zero or more of whitespaces. This match has been placed in several places because the function could be anything like these.

do_action('wp_my_action',$variable);
do_action( 'wp_my_action', $variable );
do_action  ('wp_my_action',$variable  );

\( – Matches the opening brackets of the function.

[\’\”] – Match single quotes OR double quotes. Functions may use single or double quotes around their parameters so this matches any.

(.+?) – This is the portion that matches the first parameter of the function i.e. the hook, .+ matches one or more characters while the question mark ? does a non greedy match. Read more about regex greediness here.

[,\)] – This matches a comma OR the closing brackets. The second argument is optional in the do_action() function is optional so a comma matches if there is a second parameter like this.

do_action( 'wp_my_action', $variable );

If there is only one parameter the brackets match.

do_action( 'wp_head' );

So the comment form is all yours send me your bouquets and brickbats on this script