too long

Question

I have an XML file i want to send via POST to an URL.

This is my code for it:

$url = "http://someurl.com";
$xml = file_get_contents('xml_api_actionsInsert_sample.xml');

$post_data = array('xml' => $xml);
$stream_options = array(
    'http' => array(
        'method'  => 'POST',
        'header'  => 'Content­Type: text/xml; charset=UTF­8',
        'content' =>  http_build_query($post_data)));

$context  = stream_context_create($stream_options);
$response = file_get_contents($url, null, $context);

The requirement is that the header Content-Type must be

Content­Type: text/xml; charset=UTF­8

and that the Request only contains valid XML. The xml file is valid but i'm getting an error from the API

error: Request contains no XML

Is there a mistake how i send/load the XML? Or should i try another way of sending the Request like cURL?