Get Goodreads.com books from the shelf and return JSON with no cover fallback

get_goodreads.php

<?php

function request($url) {  
	$c = curl_init();
	curl_setopt($c, CURLOPT_URL, $url);
	curl_setopt($c, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($c, CURLOPT_CONNECTTIMEOUT, 3);
	curl_setopt($c, CURLOPT_TIMEOUT, 5);
	curl_setopt($c, CURLOPT_USERAGENT,'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13');
	$response = curl_exec($c);
	$responseInfo = curl_getinfo($c);
	curl_close($c);
	if (intval($responseInfo['http_code']) == 200) {
		return $response;
	} else {
		return '';
	}
}

function getGoodreads($api, $user_id, $shelf, $per_page, $page, $sort) {

	$gr = new SimpleXMLElement(request('http://www.goodreads.com/review/list/'.$user_id.'.xml?key='.$api.'&v=2&shelf='.$shelf.'&per_page='.$per_page.'&page='.$page.'&sort='.$sort));
	
	$resp = array();
	foreach ($gr->reviews->review as $item) {
		$book = $item->book;
		$parts = explode('/', $book->image_url);
		$image = $book->image_url;
		$id = count($parts)-2;
		if($parts[$id] == 'nocover') //no cover fallback
			$image = 'http://covers.openlibrary.org/b/isbn/'.$book->isbn.'-M.jpg';
		$str = '{ "title":"'.$book->title.'", "link":"'.$book->link.'", "image":"'.$image.'", "authors": [';
		$auts = array();
		foreach ($book->authors->author as $author) {
			array_push($auts, '"'.$author->name.'"');
		}
		
		$str = $str.implode(',',$auts).']}';
		
		array_push($resp, $str);
	}
	
	return '{"books":['.implode(',',$resp).']}';
}

?>