WordPress Hooks & their Significance in Custom Development

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The WordPress platform makes it extremely easy for webmasters get it customized to meet the growing needs of a website. For this, they rely heavily on WordPress “Hooks”- Hooks are an integral part of WordPress. They provide you the ability to “hook” a custom function, to another function, which further makes it possible for you to modify the functionality of your WordPress site, without affecting the core files.

In simple words, hooks are what allow webmasters to develop, customize, or extend their website to make it more advanced and competitive. It’s quite easy and fun to play around WordPress hooks. Even if you are not a seasoned programmer but want to extend the capabilities of your website, then WordPress hooks will definitely help you in achieving your goal efficiently.

In this article, I will give you a brief introduction about WordPress hooks, their types, and how they can be used in custom WordPress development.

Understanding the Basics of WordPress Hooks

To put simply, hooks is a specific marked location in the WordPress code, wherein you can either attach or run your own code.

WordPress mainly features two types of hooks:

1. Action Hooks- these allow for the insertion and execution of custom code.

2. Filter Hooks- Allow you to modify the data being processed.

Let’s Explore Them Further

Action Hooks

The science behind the working of action hooks is extremely simple. They are some designated part within the WordPress core, theme or plugin, wherein a new code can be added with the aim of achieving a new functionality or customizations. You only need to create an action function and then execute the same with the help of certain parameters provided by the hook. Whatever the action or function you’ll create for your plugin or theme can be run anywhere the hook is available. This might occur when any requested page is being loaded or during the occurrence of a particular event.

Some of the common examples of events include where you can register a desirable action to be performed are- when you want set multiple forms of payment, add more categories, separate posts, manage contact forms, tags and so on.

Each of these events has their own hook onto which an additional action or function can be attached. So, as soon as the WordPress loads any requested page, it will first look for the “hooked into” functions, and then starts executing them based on their priority level.

Working with the Action Hook

So, let’s understand the concept of action hooks better with the examples of ‘wp_head’ and ‘wp_footer’, which are available in almost every single theme. They are mainly placeholders utilized by plugins to insert things such as meta data into the <header> and <footer> of the theme. Often times, action hooks can also be used to insert CSS or analytics code.

So, to hook into an action, first of all , we need to create a function in our theme’s functions.php file and hook it with the help of add_action ()functions. To hook your code into an action hook you can use the statement like this:

add_action( 'action_hook', 'your_function_name' );
 

The above statement will help WordPress to know that you would like to execute a function called ‘your_function_name’ whenever the system will encounter a action hook called action_hook.

The following is the simple example showing how action hooks can be created:

<?php
add_action( 'wp_head', 'my_actionhook_example' );

function activated_plugin_actionhook_example () {

echo '<meta name="description" content="Hello World! This is the meta description 
created for this page." />' . " ";

} // End my_actionhook_example()
?>
 

You can use this code inside your theme’s functions.php file. When executed it will produce a meta data in the header area of your WordPress page.

How Do Filter Hooks Work

WordPress filter hooks not only execute the piece of code but also modify some value assigned to them by the hook. This clearly implies that every filter hook comes with an associate value. The function which performs filtering must take this value, modify it, and then return the value for further use. There are mainly two ways through which filter hooks can be identified. They are:

apply_filters( $tag, $value );
apply_filters_ref_array( $tag, $args );
 

 

Now, look at the example below showcasing the creation of the ‘wp_title” filter hook. This hook will help you to alter the title of the page before it’s being displayed in the browser.

$title = apply_filters('wp_title', $title, $sep, $seplocation);
 

 

Here, $tag is the name of the hook and there are also some registered parameters which are passed to the hooks for further functionalities.

The apply_filters is used to pass a parameter to the filter. It is actually a customized function we write. In return, the filter will always return the $value parameter to the WordPress.

Filters are like actions and follows the same approach. So, here let us assume that you want to create a function, so for this you first need to register that particular hook using the below mentioned code.

add_filter ( 'hook_name', 'your_filter', [priority], [accepted_args]);
 

 

You can see here, that we have used ‘hook_name’ which is basically the name of the hook you want to register. Secondly, ‘your-filter’ is the name of the filter, ‘priority’ is optional argument, which you can use to define the hierarchy of the filters.

accepted_args is another optional argument which is helpful in defining the number of arguments your function is capable of accepting. It is mandatory for a filter to at least accept one parameter, which can be returned.

Now, look at the below example to know how a filter can be registered.

<?php
add_filter( ‘wp_title’, ‘mytest_add_sitename_to_title’, 10, 2 );
mytest_add_sitename_to_title( $title, $sep ) {

/* Retrieve site name. */
$name = get_bloginfo( ‘name’ );

/* Append site name to $title. */
$title .= $sep . ‘ ‘ . $name;

/* Return the title. */
return $title;
}
?>
 

 

In the above example you can see how we are registering a filter with the name mytest_add_sitename_to_title to the wp_title hook. Notice that we have also assigned a priority to 10 and have determed 2 arguments which will be accepted by our filter function.

It is worth noticing that our filter will ‘return’ the title back to the WordPress so that it can be displayed on the page.

Conclusion
All said and done, gaining an understanding of WordPress hooks will help you to make incredible changes in your WordPress instantly.

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About Author

Sophia Phillips has been working as a professional in WordPress development company and loves sharing information about leveraging multiple benefits of WordPress in the best possible manner. Currently, she has an impressive count of WordPress - related articles under her name.