How to use body_class filter in WordPress

body_class filter

Filters the list of CSS body class names for the current post or page.

To use the body_class filter, first you have to register it using add_filter. You can write this code into functions.php of your activated theme or in a custom WordPress Plugin.

We at WePlugins always prefer to create a custom WordPress Plugin while using hooks so nothing breaks when you update your WordPress Theme in the future.

In the below live example, we have defined a function weplugins_modify_body_class_defaults which takes 2 parameters and we registered using add_filter. The first parameter body_class is the name of the hook, the second parameter weplugins_modify_body_class_defaults is the name of the function which needs to be called, the third parameter is the priority of calling the hook if the same hook is used multiple times and the last parameter is the number of arguments (if any) to be passed in the registered function.

Sometimes, you have to remove a registered hook so you can use remove_filter to remove the body_class filter.

Parameters

Below are the 2 parameters required to use this hook.

• $classes : (string[]) An array of body class names.
• $class : (string[]) An array of additional class names added to the body.

Live Example

Example 1: Add specific CSS class by filter

Below is an example of how you can use this hook to add a specific CSS class.

    add_filter('body_class', function( $classes ) {
        return array_merge($classes, array( 'class-name' ));
    });
    

Example 2: Modify body class defaults

Here’s an example of modifying the body class defaults.

    function weplugins_modify_body_class_defaults($classes, $class) {
        // Update the $classes variable according to your website requirements and return this variable.
        // You can modify the $classes variable conditionally too if you want.
        return $classes;
    }
    // add the filter
    add_filter("body_class", "weplugins_modify_body_class_defaults", 10, 2);
    

Example 3: Remove a hook callback

To remove a hook callback, use the example below.

    remove_filter("body_class", "weplugins_modify_body_class_defaults", 10, 2);
    

Make sure to provide the same callback function name, priority, and number of arguments while removing the hook callback.

Contact Us

If you need customization or are having any trouble using this hook, please contact our WordPress Development Team and we’d be happy to assist you.