Learning about hooks is essential for anyone looking to develop or customize WordPress themes or plugins.
By enhancing the possibilities of your website, WordPress hooks may assist you in achieving your business objectives. Without altering the WordPress core itself, hooks let you interact with and change code at specified locations. They facilitate users’ ability to change and include different features in their WordPress themes and plugins.
We will discuss WordPress hooks and their function in this lesson. We will also provide useful WordPress hook examples so you can see how to use them on your website.
WordPress Hooks: What is it?
A Hook is a broad term in WordPress that denotes locations where you can append your code or modify the default actions or output of WordPress. WordPress features two classifications of hooks: actions and filters.
Using WordPress hooks, users can alter WordPress functionalities without making changes to their core. Every WordPress user must acquire knowledge about hooks, as it empowers them to edit the standard configurations of plugins or themes and ultimately establish novel functions.
What Are The Types of WordPress Hooks?
The fundamental objective of hooks is to execute a function automatically. Furthermore, this approach can append or alter WordPress characteristics without modifying its core files.
Hooks are segregated into two classifications:
- Action Hooks: These are typically hung at key points. For instance, you might be almost done developing the <head> section of a page using the wp_head action hook. Again, you might be almost done building the <body> section of a page using the wp_footer action hook.
When contractors use action hooks to enter the workspace, they are free to do almost anything they wish. This includes adding various things to the page, doing something completely different, or even sending an email.
- Filter Hooks: These work somewhat differently. Contractors who enter via action hooks can do anything they want and are not accountable to anyone. However, contractors who enter via filter hooks actually embed themselves into the typical worker’s process. They are given something to manage, such as a block of text. They must return that same block of text to the regular worker through a PHP return statement.
In a nutshell, action hooks obtain information, act on it, and don’t give anything back to the user. On the other hand, filter hooks retrieve information, alter it, and return it to the user.
WordPress Hooks: How to Use Them?
A basic understanding of HTML and PHP is necessary to use hooks. Thankfully, even for WordPress newbies, establishing action and filter hooks is not too difficult. With that said, we are going to show you how you can create an action and filter hook.
How to Create an Action Hook
In order to insert an action hook, it is necessary to activate the add_action() function within a WordPress plugin. For this, modify the functions.php file by adding the following code:
| add_action( $target_hook, $the_name_of_function_you_want_to_use, $priority, $accepted_args ); |
Hooks employ a priority scale to operate effectively. This scale is an automatic ordinal value that ranges from 1 to 999. It establishes the order of functions associated with that specific hook. The function will run sooner if the priority value is lower, and later if the priority value is greater.
The scale displays the sequence of function outputs when utilizing the same target_hook. The priority_scale’s default value is 10. The scale can be adjusted based on the number of your target_hook.
$accepted args specifies how many arguments the function will take. The default value set by the system is 1. This is an illustration of an action hook that is put at the end of the functions.php file for the Twenty Twenty-Three WordPress theme:
| <?phpfunction hook_javascript() { ?> <script> alert(‘Hi…’); </script> <?php}add_action(‘wp_head’, ‘hook_javascript’);?> |
Let’s take a closer look at the sample code:
- <?php – the location where you put the hook to work.
- function hook_javascript() – a function that alters the initial value, resulting in an alert being displayed for users.
- <script> – represents the text you want to appear on the target_hook.
- alert(‘Hi…’) – will show an alert for users with the phrase “Hi”.
- add_action – the command that creates the action hook.
- ‘wp_head’ – the target hook that the function will modify.
How to Create a Filter Hook
To create a filter hook, you can use the add_filter() function. The filter hook changes, filters, or substitutes a new value for an existing one.
Similar to an action hook, it utilizes a filter hook function such as apply_filter to filter a value.
Below is an illustration of a filter hook that we will add to the Twenty Twenty-Three WordPress theme’s functions.php file:
| add_filter( ‘the_content’, ‘change_content’ );function change_content ( $content ) { $content = ‘Here is a filter hook!’; return $content;} |
Let’s take a closer look at the code snippet:
- ‘the_content’ – the target hook that the function will modify.
- ‘change_content’ – alters the initial value, changing the actual content.
- $content = ‘Here is a filter hook!’ – substitutes the content of all your posts with the written phrase.
- return $content; – returns the new value at the end.
WordPress Hooks: Some Examples
WordPress has more than 200 hooks. Users may utilize a variety of hooks to build unique WordPress functions. Here are a few of the most well-known:
Edit the Excerpt’s Length
| function excerpt_length_example( $words ) { return 15;}add_filter( ‘excerpt_length’, ‘excerpt_length_example’ ); |
In this example, the excerpt length filter is being utilized, and it gives us an integer that specifies the length to be used with the excerpt (). You may search for apply_filters in the WordPress core code to find out more about a filter, if you are not sure what value is supplied to it.
Connect with Post Publishing
| function publish_post_tweet($post_ID) { global $post; // Code to send a tweet with post info}add_action(‘publish_post’, ‘publish_post_tweet’); |
You can see from the fictitious example above that we are hooking onto the publish_post action, which is executed when a post is published. You may use this to send a tweet containing information about the recently published content.
Although the full code for this is more complicated than we can discuss here, it is a nice illustration of an action you may perform after publishing a post.
Connect Up With Front-End Styles and Scripts
| function theme_styles() { wp_enqueue_style( ‘bootstrap_css’, get_template_directory_uri() . ‘/css/bootstrap.min.css’ ); wp_enqueue_style( ‘main_css’, get_template_directory_uri() . ‘/style.css’ ); wp_enqueue_script( ‘bootstrap_js’, get_template_directory_uri() . ‘/js/bootstrap.min.js’, array(‘jquery’), ”, true ); wp_enqueue_script( ‘theme_js’, get_template_directory_uri() . ‘/js/theme.js’, array(‘jquery’, ‘bootstrap_js’), ”, true );}add_action( ‘wp_enqueue_scripts’, ‘theme_styles’ ); |
This is a widely used hook that you learn very early in the WordPress development process. On the front end of the theme, it enables you to construct URLs for stylesheets and JavaScript files. Instead of hardcoding the URLs in your theme header, this way of connecting to CSS and JavaScript is recommended.
Make a Custom Menu Registration in the Admin
| function register_my_custom_menu_page() { add_menu_page( ‘custom menu title’, ‘custom menu’, ‘manage_options’, ‘myplugin/myplugin-admin.php’, ”, ‘dashicons-admin-site’, 6 );}add_action( ‘admin_menu’, ‘register_my_custom_menu_page’ ); |
In the aforementioned example, the admin_menu action hook is where the function register_my_custom_menu page is hooked. By doing this, you may execute code when the admin menu is produced. The most frequent usage of this is to include a unique menu link for a plugin or theme.
Initialization Hook for the Widget
| function create_my_widget() { register_sidebar(array( ‘name’ => __( ‘My Sidebar’, ‘mytheme’ ), ‘id’ => ‘my_sidebar’, ‘description’ => __( ‘The one and only’, ‘mytheme’ ), ));}add_action( ‘widgets_init’, ‘create_my_widget’ ); |
A relatively straightforward and frequent addition to a theme or plugin is the creation of a widget. You need to achieve this by hooking into the widget_init action. This hook enables you to execute your code when WordPress generates widgets, making it the ideal hook for simultaneously adding your own widgets.
FAQ
Should You Use WordPress Hooks?
Indeed, WordPress hooks are essential because they let programmers alter and expand the features of the core, themes, and plugins of WordPress without modifying the core code. They offer a methodical and systematic manner to update data and integrate custom code, which makes WordPress development more adaptable and scalable.
In WordPress, Where Do I Add Hooks?
With WordPress, hooks can be put in a standalone plugin file, the functions.php file of a plugin or theme, or both. The add_action() function is used to add action hooks, while the add_filter() function is used to add filter hooks.
What Are the Fundamental WordPress Plugin Hooks?
Action hooks and filter hooks are the fundamental hooks used in WordPress plugin development. Although filter hooks allow developers to alter data before it is shown on the website, action hooks allow them to run custom code at particular locations in the WordPress core code.
Conclusion
WordPress hooks provide developers with the flexibility to customize WordPress in a variety of ways. Hooks enable you to modify WordPress’s behavior without modifying its core files. This allows you to create unique features and functionalities for your site.
With a solid understanding of how hooks work and the different types of hooks available, you can take your WordPress development skills to the next level. Whether you are building a custom theme or developing a plugin, WordPress hooks provide the building blocks for creating a powerful and flexible WordPress site that meets your specific needs.
