why i cant json_decode my response from API? - php

Question

I have tried to get data from this source, which is school detail on my country. but when i get the response, i cannot decode my response and it say Null. Idk why, but when i try to copy and paste my response result to hardcode, it can be decoded. why ?
i have tried all possible way to solve this, nothing work.
this is my code :
$client = new \GuzzleHttp\Client();
$res = $client->request('GET', 'http://jendela.data.kemdikbud.go.id/api/index.php/Csekolah/detailSekolahGET?mst_kode_wilayah=026700');
$response = $res->getBody()->getContents();
$result = json_decode($response); // this return NULL
//But when i going to return the $response, it show the response.
return $response;
I expect to access the data or maybe just decode my code, and it will help me a lot.
FYI, I'am using Guzzle 6 and Laravel 5.7 to work with this.
i hope someone can try too access it to and help me.
or maybe if you want to test it you can use Curl Ways :
$param = 'index.php/Csekolah/detailSekolahGET?mst_kode_wilayah=026700';
$url='http://jendela.data.kemdikbud.go.id/api/'.$param;
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec ($ch);
return $response;

Answer 1

The json_decode document says:
NULL is returned if the json cannot be decoded or if the encoded data
is deeper than the recursion limit.
You can use json_last_error or json_last_error_msg function to determine the problem.
I can't get the whole response, it's timeout and terminated.

Answer 2

Remove the line return $response;
and try the following code:
$enc = mb_detect_encoding($response);
if($enc == 'UTF-8') {
$response = preg_replace('/[^(\x20-\x7F)]*/','', $response);
}
echo "<pre>";
print_r(json_decode($response,true));

Answer 3

Per the documentation:
NULL is returned if the json cannot be decoded or if the encoded data is deeper than the recursion limit
Source: json_decode
Some debugging tips:
Make sure all the characters fall within utf8
Specify a depth value(higher than the default)
Make use of json_last_error see: json_last_error
If debugging tip 1 happens to be the cause of the issue, see if you can limit the return to not include the offending characters.