Reply To: Action hook when specific field changes

• James

• July 6, 2016 at 3:33 pm

Hi @giu-tae-kim

I think you can use the acf/update_value filter or the acf/save_post action hooks to do it. Here’s the example how to do it with acf/update_value:

function my_acf_update_value( $value, $post_id, $field  ) {
    // only do it to certain custom fields
    if( $field['name'] == 'custom_field_name' ) {
        
        // get the old (saved) value
        $old_value = get_field('custom_field_name', $post_id);
        
        // get the new (posted) value
        $new_value = $_POST['acf']['field_1234567890abc'];
        
        // check if the old value is the same as the new value
        if( $old_value != $new_value ) {
            // Do something if they are different
        } else {
            // Do something if they are the same
        }
    }

	// don't forget to return to be saved in the database
    return $value;
    
}

// acf/update_value - filter for every field
add_filter('acf/update_value', 'my_acf_update_value', 10, 3);

Where ‘field_1234567890abc’ is the field key of your custom field(‘custom_field_name’ in this case).

I hope this helps 🙂