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How to use add_meta_type_metadata filter in WordPress

Sandeep Kumar Mishra
Sandeep Kumar Mishra
July 12, 2022
5 minutes read

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 Flipper Code, 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 modify_add_meta_type_metadata_defaults which takes 5 parameters and we registered using add_filter. The first parameter add_meta_type_metadata is name of the hook, The second parameter modify_add_meta_type_metadata_defaults is name of the function which need to be called, third parameter is the priority of calling the hook if same hook is used multiple times and the last parameter is the number of arguments (if any) to be passed in the registered function.

Sometime, you have to remove a registered hook so you can use remove_filter to remove add_meta_type_metadata filter.


    Below are the 5 parameters are 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 Example

apply_filters( "add_{$meta_type}_metadata", null|bool $check, int $object_id, string $meta_key, mixed $meta_value, bool $unique )

Below is an example how you can use this hook.

                        function 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", "modify_add_meta_type_metadata_defaults", 10, 5 );

To remove a hook callback, use the example below.

remove_filter( "add_meta_type_metadata", "modify_add_meta_type_metadata_defaults", 10, 5 );

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

Flipper Code is a Premium WordPress Plugins development company and integrating new functionalites into WordPress sites in form of custom WordPress Plugins since 2012. If you’re having any trouble using this hook, please contact our WordPress Development Team and we’d be happy to assist you.

Sandeep Kumar Mishra

Sandeep Kumar Mishra writes about WordPress and Artificial Intelligence, offering tips and guides to help you master your website and stay updated with the latest tech trends.

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