Toolbox Action - toolbox_add_conditional_options

toolbox_example_add_conditional.php

<?php
add_action( 'toolbox_add_conditional_options' , 'add_some_new_conditional_feature', 10, 1 );

function add_some_new_conditional_feature() {

	toolboxExtender::add_conditional_option(
									// filter name
									'conditional_filter_check_parameter',
									// option key and title
									array('key'=> 'check_parameter' , 'title' => __('Check URL Parameter', 'textdomain') ),
									// fields that are part of this options settings.
									// No toggling of subfields or forms
									array(
										'query_parameter' => array(
											'type'          => 'text',
											'label'			=> __( 'query parameter to check for', 'textdomain' ),
										),
										'query_value' => array(
											'type'          => 'text',
											'label'			=> __( 'if equal to', 'textdomain' ),
										),
									)
								);

	add_filter( 'conditional_filter_check_parameter' , 'check_query_parameter' , 10, 3 );

	function check_query_parameter ( $is_visible, $param , $node ) {

    if ( !isset( $_GET[$param['query_parameter']]) || $_GET[$param['query_parameter']] !== $param['query_value'] ) return false;
    return true;
	}

}