No response from XML using cURL - php

Question

I am using a simple cURL statement to parse XML on my site. When the API is up and working it works fine, however as soon as the API does down for any reason the entire site crashes.
$url = 'http://www.mydomain.com/webservicexample';
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, 0);
$data = curl_exec($ch);
curl_close($ch);
$xml = new SimpleXmlElement($data);
Is there a conditional I can put around the url so that it only carries out the cURL script if there's a positive response from the API? I tried the following but it didn't work because it never got a server response to give any headers:
$url_headers = #get_headers($url);
if($url_headers[0] == 'HTTP/1.1 200 OK') {
// do script
}
Any help/advice much appreciated!

Answer 1

You can check the return value of curl_exec():
if (false === ($data = curl_exec($ch))) {
die("Eek! Curl error! " . curl_error($ch));
}
And check the response headers too:
if (200 !== (int)curl_getinfo($ch, CURLINFO_HTTP_CODE)) {
die("Oh dear, no 200 OK?!");
}

Answer 2

In the end I was able to get it working by setting a timeout time with CURLOPT_TIMEOUT and CURLOPT_CONNECTTIMEOUT and then put a conditional around it using curl_errno().
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 3);
curl_setopt($ch, CURLOPT_TIMEOUT, 3);
$data = curl_exec($ch);
if(!curl_errno($ch))
{
curl_close($ch);
$xml = new SimpleXmlElement($data);
return $xml;
}