Как генерировать файл json для yandex map на вордпресс?

<?php 
	require_once( $_SERVER['DOCUMENT_ROOT'] . '/wp-load.php' );
	global $post;
	global $wpdb;
?>
<?php $markers = get_posts ('post_type=markers&order=ASC'); ?> 
<?php $arr = array(); ?>
	<?php if ($markers) :?>
		<?php foreach ($markers as $post) : setup_postdata ($post); ?>
			<?php 
				$arr[get_the_ID()]['type'] = 'Feature';
				$arr[get_the_ID()]['id'] = '0'; 
				$arr[get_the_ID()]['geometry']['type'] = 'Point'; 
				$arr[get_the_ID()]['geometry']['coordinates'] = array(55.831903, 37.411961); 
				$arr[get_the_ID()]['properties']['balloonContent'] = 'Содержимое балуна';
				$arr[get_the_ID()]['properties']['clusterCaption'] = 'Еще одна метка'; 
				$arr[get_the_ID()]['properties']['hintContent'] = 'Текст подсказки';
			?>
		<?php endforeach; ?>
	<?php endif; ?>
<?php wp_reset_postdata(); ?>

<?php
	$array = array(
		"type" => "FeatureCollection",
		"features" => array_values($arr)
	);
?>
<?php echo json_encode($array); ?>