Batch requests failed decoding body

[EsKuel]

Hello,

I've been using your library since last year to handle OData requests, thanks for your work, it really helped a lot.

When using $client->batch() against SAP SuccessFactors OData v2, the client throws an ODataException during decodeBody().

Here an example of a simple query made to SuccessFactors with the library :

$batch = $client->batch();

$batch->get("EmpJob?\$top=5&\$format=json", 'get-empjob');
$response = $batch->execute();

After debugging, we got the response, and the decode part fails, with this error : The HTTP client sent back an invalid response.

Here is the response (redacted for privacy reasons) :

--batch_f20d8021-677a-4f93-8e62-862b6f383d15
Content-Type: application/http
Content-Transfer-Encoding: binary

HTTP/1.1 200 OK
Content-Type: application/json;charset=utf-8
DataServiceVersion: 2.0
Record-Count: 5
X-SF-Record-Count-Recursive: 5
successfactors-message: X-SF-Correlation-Id, successfactors-sourcetype are missing in request headers
Content-Length: 76038

{
"d" : {
"results" : [REDACTED]
}
}

--batch_f20d8021-677a-4f93-8e62-862b6f383d15--

What happened is in the decodeBody() function in ODataResponse :

    private function decodeBody()
    {
        $decodedBody = json_decode($this->body, true, 512, JSON_BIGINT_AS_STRING);
        if ($decodedBody === null) {
            $matches = null;
            preg_match('~\{(?:[^{}]|(?R))*\}~', $this->body, $matches);
            $decodedBody = json_decode($matches[0], true, 512, JSON_BIGINT_AS_STRING);
            if ($decodedBody === null) {
                $decodedBody = array();
            }
        }
        return $decodedBody;
    }

First try fail, because the body isnt a full JSON, then the preg_match doesnt match anything, so when trying to decode $matches[0], we got an ErrorException because of "Undefined array key 0", so ODataRequest throw the ODataException with the UNABLE_TO_PARSE_RESPONSE constant.

I'm quite not sure why since I'm not really an OData expert, I'm willing to help as far as I can.

Thanks for your help and for your really good lib !

Have a nice day.

[jphooiveld]

I think batch requests are pretty broken at the moment with multiple get calls or a get call with too much data. I tried the changes from copilot but it doesn't work in that case. Maybe I'm missing something @anderly? I looked through the documentation and examples but couldn't find much how to parse response from a batch request.

I just think the decodeBody method in the ODataResponse class cannot handle this at the moment. Maybe we need to use something like the "riverline/multipart-parser" package to decode each get call to to an individual array. But still if an individual get call has too much data it will also fail. Maybe we need to rely on the content-type header in case of multipart to determine if it is json and just assume the whole body is also json. Your thoughts about this @anderly?

The workaround I use at the moment is to set the entity return type to "stream" with:

$client->setEntityReturnType('stream');

Then I can just parse the raw response from the execute method with the library I just mentioned with the following code:

final class MultiPartParser
{
    public static function parse(\GuzzleHttp\Psr7\Response $response): iterable
    {
        $contentType = $response->getHeaderLine('Content-Type');

        if (!str_contains($contentType, 'multipart')) {
            return [];
        }

        $stream = fopen('php://temp', 'rwb+');
        fwrite($stream, "Content-Type: $contentType\r\n\r\n");
        fwrite($stream, $response->getBody()->getContents());
        rewind($stream);

        $multipart = new \Riverline\MultiPartParser\StreamedPart($stream);

        if (!$multipart->isMultiPart()) {
            return [];
        }

        foreach ($multipart->getParts() as $part) {
            $innerResponse = \GuzzleHttp\Psr7\Message::parseResponse($part->getBody());
            
            yield [
                'body' => $innerResponse->getBody()->getContents(),
                'headers' => $innerResponse->getHeaders(),
            ];
        }
    }
}