OneDriveResumableUpload::getLocationForResumableUpload

protected function getLocationForResumableUpload()
{
	if(!$this->checkRequiredInputParams($this->fileData->toArray(), array(
		'name', 'size',
	)))
	{
		return null;
	}

	$http = new HttpClient(array(
		'redirect' => false,
		'socketTimeout' => 10,
		'streamTimeout' => 30,
		'version' => HttpClient::HTTP_1_1,
	));
	$this->setBearer($http);
	$http->setHeader('Content-Type', 'application/json; charset=UTF-8');

	$postFields = Json::encode($this->getPostFieldsForUpload($this->fileData));
	if($http->post($this->uploadPath . static::SUFFIX_TO_CREATE_UPLOAD_SESSION, $postFields) === false)
	{
		$errorString = implode('; ', array_keys($http->getError()));
		$this->errorCollection[] = new Error(
			$errorString, self::ERROR_HTTP_GET_LOCATION_FOR_UPLOAD
		);
		return null;
	}

	if(!$this->documentHandler->checkHttpResponse($http))
	{
		return null;
	}

	$responseData = Json::decode($http->getResult());
	if($responseData === null)
	{
		$this->errorCollection->add(array(
			new Error('Could not decode response as json', self::ERROR_BAD_JSON)
		));
		return null;
	}


	return $responseData['uploadUrl'];
}