How to use add_meta_type_metadata filter in WordPress

add_meta_type_metadata filter

The dynamic portion of the hook name, $meta_type, refers to the meta object type (post, comment, term, user, or any other type with an associated meta table). Returning a non-null value will effectively short-circuit the function.

To use add_meta_type_metadata 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_add_meta_type_metadata_defaults which takes 5 parameters and we registered using add_filter. The first parameter add_meta_type_metadata is the name of the hook, the second parameter weplugins_modify_add_meta_type_metadata_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 add_meta_type_metadata filter.

Parameters

Below are the 5 parameters required to use this hook.

• $check : (null|bool) Whether to allow adding metadata for the given type.
• $object_id : (int) ID of the object metadata is for.
• $meta_key : (string) Metadata key.
• $meta_value : (mixed) Metadata value. Must be serializable if non-scalar.
• $unique : (bool) Whether the specified meta key should be unique for the object.

Live Examples

Example 1: Basic Usage

Below is an example of how you can use this hook.

    function weplugins_modify_add_meta_type_metadata_defaults($check, $object_id, $meta_key, $meta_value, $unique) {
        // Update the $check variable according to your website requirements and return this variable. You can modify the $check variable conditionally too if you want.
        return $check;
    }
    // add the filter
    add_filter("add_meta_type_metadata", "weplugins_modify_add_meta_type_metadata_defaults", 10, 5);
    

Example 2: Conditional Modification

Here is how you can conditionally modify the $check variable based on certain conditions:

    function weplugins_modify_add_meta_type_metadata_defaults($check, $object_id, $meta_key, $meta_value, $unique) {
        if ($meta_key == 'special_key') {
            $check = true;
        }
        return $check;
    }
    // add the filter
    add_filter("add_meta_type_metadata", "weplugins_modify_add_meta_type_metadata_defaults", 10, 5);
    

Example 3: Removing the Hook Callback

To remove a hook callback, use the example below.

    // remove the filter
    remove_filter("add_meta_type_metadata", "weplugins_modify_add_meta_type_metadata_defaults", 10, 5);
    

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

Contact Us

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