ExactOnline API en OData - php

Question

I am struggling with the API of Exact Online.
Using this example code to retrieve information of the server:
$response = $exactApi->sendRequest("crm/Accounts?$filter=substringof('test', Name) eq true', 'get');
Above returns a Bad Request. Anyone got a clue how to fix this?
The function 'send request':
public function sendRequest($url, $method, $payload = NULL)
{
if ($payload && !is_array($payload)) {
throw new ErrorException('Payload is not valid.');
}
if (!$accessToken = $this->initAccessToken()) {
throw new ErrorException('Access token was not initialized');
}
$requestUrl = $this->getRequestUrl($url, array(
'access_token' => $accessToken
));
// Base cURL option
$curlOpt = array();
$curlOpt[CURLOPT_URL] = $requestUrl;
$curlOpt[CURLOPT_RETURNTRANSFER] = TRUE;
$curlOpt[CURLOPT_SSL_VERIFYPEER] = TRUE;
$curlOpt[CURLOPT_HEADER] = false;
if ($method == self::METHOD_POST) {
$curlOpt[CURLOPT_HTTPHEADER] = array(
'Content-Type:application/json',
'access_token:' . $accessToken,
'Content-length: ' . strlen(json_encode($payload))
);
$curlOpt[CURLOPT_POSTFIELDS] = json_encode($payload);
$curlOpt[CURLOPT_CUSTOMREQUEST] = strtoupper($method);
}
$curlOpt[CURLOPT_ENCODING] = '';
$curlHandle = curl_init();
curl_setopt_array($curlHandle, $curlOpt);
return curl_exec($curlHandle);
}

Answer 1

Tested this.
crm/Accounts?$select=Name&$filter=substringof('Lennert',Name) : OK
crm/Accounts?$select=Name&$filter=substringof('Lennert', Name) eq true : NOK, error 400
crm/Accounts?\$select=Name&$filter=substringof(Name, 'Lennert') eq true : NOK, error 400
First option works but is not according to OData v2 specifications which Exact Online uses. Will be discussed with development to see what can be done for this.