Getting JSON Object by calling a URL with parameters in PHP - 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'};