php - send and receive xml documents - php

Question

I am trying to get a xml document back from the webserver that also supports php.
It's something similar to what the traditional web services do but i want to achieve it in php. Is this even possible?
To be more specific about my needs -
I want to send a xml document as a request to the server, have PHP do some processing on it and send me back an xml document as a response.
Thanks in advance.

Answer 1

Maybe you simply want http://php.net/SOAP ?
If not SOAP, then you can send your XML POST request and use $xml = file_get_contents('php://input'); to dump it to a variable that you can feed to http://php.net/DOM or other XML processors.
After processing, you header('Content-Type: text/xml'); (or application/xml) and output the modified XML document.

Answer 2

Super simple example of reading an XML request body:
$request = http_get_request_body();
if($request && strpos($request, '<?xml') !== 0){
// not XML do somehting appropriate
} else {
$response = new DomDocment(); // easier to manipulate when *building* xml
$requestData = DomDocument::load($request);
// process $requestData however and build the $response XML
$responseString = $response->saveXML();
header('HTTP/1.1 200 OK');
header('Content-type: application/xml');
header('Content-length: ', strlen($responseString));
print $responseString;
exit(0);
}

Answer 3

use curl.
//open connection
$ch = curl_init();
//set the url, number of POST vars, POST data
curl_setopt($ch,CURLOPT_URL,$url);
curl_setopt($ch,CURLOPT_POST,1);
curl_setopt($ch,CURLOPT_POSTFIELDS,$xmlString);
//execute post
$result = curl_exec($ch);