Check if remote file is well-formed XML with PHP

Question

I have a PHP-driven site that includes an XML stock feed, which is remotely served from ASP (i.e. the XML feed url is of the order: http://remote.com/client.asp).

As the feed is often unavailable (by which I mean the site returns an ASP error) I'd like to check if the feed is well-formed XML before including it. My usual url_exists function doesn't do the trick as of course the URL does exist even when 'erroring'.

TIA.

Answer 1

Use cURL to get the result and simplexml to check if the XML is well-formed.

$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, "http://remote.com/client.asp");
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
$output = curl_exec($curl);
curl_close($curl);
if (simplexml_load_string($output)) {
  // well-formed XML
} else {
  // it isn't
}