Getting JSON Object by calling a URL with parameters in PHP

Question

I'm trying to get json data by calling moodle url:

https://<moodledomain>/login/token.php?username=test1&password=Test1&service=moodle_mobile_app

the response format of moodle system is like this:

{"token":"a2063623aa3244a19101e28644ad3004"}

The result I tried to process with PHP:

if ( isset($_POST['username']) && isset($_POST['password']) ){

                 // test1                        Test1

    // request for a 'token' via moodle url
    $json_url = "https://<moodledomain>/login/token.php?username=".$_POST['username']."&password=".$_POST['password']."&service=moodle_mobile_app";

    $obj = json_decode($json_url);
    print $obj->{'token'};         // should print the value of 'token'

} else {
    echo "Username or Password was wrong, please try again!";
}

Result is: undefined

Now the question: How can I process the json response format of moodle system? Any idea would be great.

[UPDATE]: I have used another approach via curl and changed in php.ini following lines: *extension=php_openssl.dll*, *allow_url_include = On*, but now there is an error: Notice: Trying to get property of non-object. Here is the updated code:

function curl($url){
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $data = curl_exec($ch);
    curl_close($ch);
    return $data;
}

$moodle = "https://<moodledomain>/moodle/login/token.php?username=".$_POST['username']."&password=".$_POST['password']."&service=moodle_mobile_app";
$result = curl($moodle);

echo $result->{"token"}; // print the value of 'token'

Can anyone advise me?

Answer 1

json_decode() expects a string, not a URL. You're trying to decode that url (and json_decode() will NOT do an http request to fetch the url's contents for you).

You have to fetch the json data yourself:

$json = file_get_contents('http://...'); // this WILL do an http request for you
$data = json_decode($json);
echo $data->{'token'};