Moodle in English: Weird behavior of curl in moodle enviroment (V3.1)

Hello,

I am extending moodle's core submission plugin to execute curl rest request upon submitting assignment. However it behaves oddly and seemingly does empty request.

I decided to test the code shown below in isolated enviroment that is separate from moodle. Everything worked without issues so i'm left baffled without any clue on whats going on.

CODE (submissionplugin.php) :

public function submit_for_grading($submission) {

$url = 'localhost:8080/snacks';

$asdata = array('asid'=> 2, 'userid' => 3, 'sbm_fpth' => 5);

$builtquery = http_build_query($asdata);

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, $url);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

curl_setopt($ch, CURLINFO_HEADER_OUT, 1);

curl_setopt($ch, CURLOPT_POST, 1);

curl_setopt($ch, CURLOPT_POSTFIELDS, $builtquery);

$result = curl_exec($ch);

echo $result;

curl_close($ch);

}

Server response:

I am sure i have missed something or i'm executing this logic in wrong place.

Thanks in advance!

I do not think that you need to use http_build_query and perhaps your URL should be 'http://localhost:8080/snacks'

This code works for me in moodle. In $postdata I simply pass an array of parameters.

public static function curl_fetch($url,$postdata=false)
{
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_HEADER, false);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    if ($postdata) {
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $postdata);
    }
    $contents = curl_exec($ch);
    curl_close($ch);
    return $contents;
}

Hi Daryoush,

have you tried the moodle core class "curl"?

Here an example:

require_once('config.php');
require_once($CFG->libdir.'/filelib.php');
$curl = new curl();

$url = 'http://localhost:8080/snacks';
$params = array('asid'=> 2, 'userid' => 3, 'sbm_fpth' => 5);
$result = $curl->get($url, $params);
print_object($result);

Best regards
Andreas

I was given advice to use only internal CURL class when developing with Moodle because - "Many moodle sites sit behind a web proxy and moodle uses an internal curl() class to manage this" by Dan Mardsen.
So it's probably way to go. You can find it in lib/filelib.php around line 2704.

I remember when I just started to work with internal CURL I had a problem to reach APIs in development (maybe because of non : 80 port or because of SSL), so ngrok ( https://ngrok.com/ ) might be handy.

There is a Moodle admin setting for your proxy.

The Moodle curl class automatically uses those admin settings, and then everything just works (if you set those admin settings).

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Weird behavior of curl in moodle enviroment (V3.1)