Using WordPress ‘get_{$meta_type}_metadata’ PHP filter

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The get_{$meta_type}_metadata WordPress PHP filter short-circuits the return value of a meta field. The dynamic portion, $meta_type, refers to the meta object type (post, comment, term, user, or any other type with an associated meta table).

Usage

add_filter( 'get_post_metadata', 'your_custom_function', 10, 4 );
function your_custom_function( $value, $object_id, $meta_key, $single ) {
    // your custom code here

    return $value;
}

Parameters

  • $value: (mixed) The value to return, either a single metadata value or an array of values depending on the value of $single. Default null.
  • $object_id: (int) ID of the object metadata is for.
  • $meta_key: (string) Metadata key.
  • $single: (bool) Whether to return only the first value of the specified $meta_key.
  • $meta_type: (string) Type of object metadata is for. Accepts ‘post’, ‘comment’, ‘term’, ‘user’, or any other object type with an associated meta table.

More information

See WordPress Developer Resources: get_{$meta_type}_metadata

Examples

Modify post metadata

Modify the value of a specific post metadata.

add_filter( 'get_post_metadata', 'modify_post_metadata', 10, 4 );
function modify_post_metadata( $value, $object_id, $meta_key, $single ) {
    if ( 'custom_key' === $meta_key ) {
        $value = 'New Value';
    }
    return $value;
}

Hide user metadata

Hide a specific user metadata.

add_filter( 'get_user_metadata', 'hide_user_metadata', 10, 4 );
function hide_user_metadata( $value, $object_id, $meta_key, $single ) {
    if ( 'hidden_key' === $meta_key ) {
        return false;
    }
    return $value;
}

Filter term metadata

Filter a specific term metadata.

add_filter( 'get_term_metadata', 'filter_term_metadata', 10, 4 );
function filter_term_metadata( $value, $object_id, $meta_key, $single ) {
    if ( 'term_key' === $meta_key ) {
        $value = 'Filtered Value';
    }
    return $value;
}

Modify comment metadata

Modify the value of a specific comment metadata.

add_filter( 'get_comment_metadata', 'modify_comment_metadata', 10, 4 );
function modify_comment_metadata( $value, $object_id, $meta_key, $single ) {
    if ( 'comment_key' === $meta_key ) {
        $value = 'New Comment Value';
    }
    return $value;
}

Short-circuit metadata retrieval

Short-circuit metadata retrieval for a specific key.

add_filter( 'get_post_metadata', 'short_circuit_metadata', 10, 4 );
function short_circuit_metadata( $value, $object_id, $meta_key, $single ) {
    if ( 'short_circuit_key' === $meta_key ) {
        return 'Short-circuit Value';
    }
    return $value;
}