JSON WordPress feed

json-feed.php

<?php
/*
 * JSON feed
 * adapted from http://www.noeltock.com/web-design/wordpress/events-custom-post-types-fullcalendar-json-wordpress/
*/

function event_json_feed() {
    header('Content-Type:application/json');
   
    global $wpdb;

    // - grab date barrier -
    $today = strftime('%F %R', strtotime('today 0:00'));
     
    // - query -
    global $wpdb;
    $querystr = "
        SELECT *
        FROM $wpdb->posts wposts, $wpdb->postmeta metastart, $wpdb->postmeta metaend
        WHERE (wposts.ID = metastart.post_id AND wposts.ID = metaend.post_id)
        AND (metaend.meta_key = '_end_timestamp' AND metaend.meta_value > '$today' )
        AND metastart.meta_key = '_start_timestamp'
        AND wposts.post_type = 'event'
        AND wposts.post_status = 'publish'
        ORDER BY metastart.meta_value ASC LIMIT 500
     ";
     
    $events = $wpdb->get_results($querystr, OBJECT);
    $jsonevents = array();
     
    // - loop -
    if ($events) {
	    global $post;
	    foreach ($events as $post) {
		    setup_postdata($post);
		     
		    // - custom post type variables -
		    $custom = get_post_custom(get_the_ID());
		    $start = $custom["_start_timestamp"][0];
		    $end = $custom["_end_timestamp"][0];
		     
		    // - grab gmt for start -
		    $gmts = date('Y-m-d H:i:s', strtotime($start));
		    $gmts = get_gmt_from_date($gmts); // this function requires Y-m-d H:i:s
		    $gmts = strtotime($gmts);
		     
		    // - grab gmt for end -
		    $gmte = date('Y-m-d H:i:s', strtotime($end));
		    $gmte = get_gmt_from_date($gmte); // this function requires Y-m-d H:i:s
		    $gmte = strtotime($gmte);
		     
		    // - set to ISO 8601 date format -
		    $stime = date('c', $gmts);
		    $etime = date('c', $gmte);
		     
		    // - json items -
		    $jsonevents[]= array(
		        'title' => $post->post_title,
		        'allDay' => false, // <- true by default with FullCalendar
		        'start' => $stime,
		        'end' => $etime,
		        'url' => get_permalink($post->ID)
		        );
		     
		    }
	    }
     
    // - fire away -
    echo json_encode($jsonevents);

}

add_feed('json', 'event_json_feed');

?>