Add custom field to image editor

Question

How do I add custom field to the image editor, such as under the image 'Description' field? To be much clearer, it's where the settings for the images are after you upload an image in the attachment pop-up window.

Answer 1

To add a custom field to attachments, place the following code in your functions.php.

add_filter('attachment_fields_to_edit', 'edit_media_custom_field', 11, 2 );
add_filter('attachment_fields_to_save', 'save_media_custom_field', 11, 2 );

function edit_media_custom_field( $form_fields, $post ) {
    $form_fields['custom_field'] = array( 'label' => 'Custom Field', 'input' => 'text', 'value' => get_post_meta( $post->ID, '_custom_field', true ) );
    return $form_fields;
}

function save_media_custom_field( $post, $attachment ) {
    update_post_meta( $post['ID'], '_custom_field', $attachment['custom_field'] );
    return $post;
}

To output that data you can use the following in the loop:

get_post_meta( get_the_ID(), '_custom_field', true ) );