Prettify respone from DB via filters

prettifier.php

<?php

public function _prettify_order_response($order)
{
	// Load dependencies
	$subjects = $this->subjects;

	// Init field->filter array
	$nice_response = array(
		'id'             => 'task_id',
		'info'           => 'task_info',
		'deadline'       => function ($deadline) {
			$_deadline = new DateTime($deadline);
			return array(
				'str' => $deadline,
				'ts'  => $_deadline->getTimestamp()
			);
		},
		'placement_date' => function ($placement_date) {
			$_placement_date = new DateTime($placement_date);
			return array(
				'str' => $placement_date,
				'ts'  => $_placement_date->getTimestamp()
			);
		},
		'price'          => null,
		'status'         => null,
		'gnt'            => null,
		'refund'         => null,
		'order_title'    => null,
		'category'       => array(
			'args' => 'cat_id',
			'func' => function ($cat_id) use ($subjects) {
				return array(
					'id'      => $cat_id,
					'subject' => array(
						'id' => $subjects->get($cat_id, array('parent_id')),
					)
				);
			}
		),
		'level'          => array(
			'args' => 'level_id',
			'func' => function ($level_id) {
				return array(
					'id' => $level_id
				);
			}
		),
		'process_status' => function ($process_status) {
			return array(
				'id' => $process_status
			);
		}
	);

	return prettify($nice_response, $order);
}

prettifier_helper.php

<?php

/**
 * Generate nice response for RESTful API
 * Magic start here
 *
 * Filters:
 * 1. string - simple replacement
 * 2. lambda - call a function with $field as argument
 * 3. array - call a function with $filter['args'] as arguments
 * 4. NULL - nothing to change
 *
 * @param $expected_response
 * @param $original_response
 * @param bool $assoc
 * @return array
 */
function prettify($expected_response, $original_response, $assoc = false)
{
  return array_combine(array_keys($expected_response), array_map(function ($filter, $field) use ($original_response) {
		switch (gettype($filter)) {
			case 'string' :
				return $original_response->$filter;
				break;
			case 'object':
				return $filter($original_response->$field);
				break;
			case 'array':
				return call_user_func_array($filter['func'], array_map(function ($argument) use ($original_response) {
					$argument = trim($argument);
					return $original_response->$argument;
				}, explode(',', $filter['args'])));
				break;
			case 'NULL':
			default:
				return $original_response->$field;
		}
	}, $expected_response, array_keys($expected_response)));
}