Failsafe for PHP Simple HTML DOM Parser - php

Question

Using PHP Simple HTML DOM Parser (http://simplehtmldom.sourceforge.net), I recently had a situation where the external webpage I routinely fetch was not responding (their servers were down). Because of this the my own website would not load (instead it showed errors after a lengthy wait period).
What would be the best way to add a failsafe to this parser upon an unsucessful fetch attempt?
I have tried to use the following below without success.
include('./inc/simple_html_dom.php');
$html = file_get_html('http://client0.example.com/dcnum.php?count=1');
$str = $html->find('body',0);
$num = $str->innertext;
if(!$html)
{
error('No response.')
}
$html->clear();
unset($html);
EDIT: I haven't had time to try this yet, but perhaps I could place my 'if' statement directly after the first line (before the $html->find('body',0) part).

Answer 1

If I understand you want to prevent going offline when they are offline...
If you are using PHP's curl bindings, you can check the error code using curl_getinfo as such:
$handle = curl_init($url);
curl_setopt($handle, CURLOPT_RETURNTRANSFER, TRUE);
/* Get the HTML or whatever is linked in $url. */
$response = curl_exec($handle);
/* Check for 404 (file not found). */
$httpCode = curl_getinfo($handle, CURLINFO_HTTP_CODE);
if($httpCode == 404) {
/* Handle 404 here. */
}
curl_close($handle);
/* Handle $response here. */
Also you can check for other error codes, as 500, 503, etc.

Answer 2

Took me literally hours to figure out this, surprisingly very few clues on how to handle errors with simple_html_dom.
Basically all you have to do is get rid of file_get_html, ->load_file or what ever simple_html_dom-specific method you used to load the content, and instead do it with curl, and pass it to str_get_html.
I used the code of the other answer, here is how you can use it :
function get_with_curl_or_404($url){
$handle = curl_init($url);
curl_setopt($handle, CURLOPT_RETURNTRANSFER, TRUE);
$response = curl_exec($handle);
$httpCode = curl_getinfo($handle, CURLINFO_HTTP_CODE);
curl_close($handle);
if($httpCode == 404 || !$response) { // arbitrary choice to return 404 when anything went wront
return 404;
} else {
return $response;
}
}
$html = str_get_html(get_with_curl_or_404("http://your-
url.com/index.html"));
if ($html == 404) {
// Do whatever you want
} else {
// If not 404, you can use it as usually, ->find(), etc
}
If it is much more stable on big websites.
If it was the kind of behavior you were looking for, please try it out, and tell me I didn't make your day.