Send an XML post request to a web server with CURL

Question

I am trying to send a request to a web server using php and curl. I haven't done something like this before and although there are many nice examples online I have some difficulties understanding some of the curl commands.

This is what I want to do: There is an established web service (for example: Web map service) and I want my php code to send a post XML request to this service. As a respond I want to get an XML file.

This is what I have till now:

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, ''); 
    /*curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: text/xml'));*/
    /* curl_setopt($ch, CURLOPT_HEADER, 0);*/
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 0);
    /*curl_setopt($ch, CURLOPT_REFERER, '');*/
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $ch_result = curl_exec($ch);
    curl_close($ch);
    echo $ch_result;

As I said I am quite new in php and also in using curl and I think I am missing some concepts. My questions are: 1) What is the string (link) that I have to put in the:

          curl_setopt($ch, CURLOPT_URL, ''); 

Is it the host name of the service which I want to send the request?

2) In row 6 the variable $xml contains the xml file that I want to send as a request. Is it correct or this variable is supposed to contain something else?

3) In which cases do I need to use a httpheader or header (row3 and row4);

Thanks for the help. Dimitris

Answer 1

Try it this way:

  $url = 'https://android.googleapis.com/gcm/send';
  $ch = curl_init();
  curl_setopt( $ch, CURLOPT_URL, $url );
  curl_setopt( $ch, CURLOPT_POST, true );
  curl_setopt( $ch, CURLOPT_HTTPHEADER, array('Content-Type: text/xml'));
  curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
  curl_setopt( $ch, CURLOPT_POSTFIELDS, "<xml>here</xml>" );
  $result = curl_exec($ch);
  curl_close($ch);

For more details visit: http://php.net/manual/en/function.curl-setopt.php

Answer 2

I think using the HTTP classes may be better suited for making HTTP requests.

See http://www.php.net/manual/intro.http.php .

Also, there are specific WMS libraries for PHP, e.g. http://docs.huihoo.com/geoserver/1.6.0/Parsing%20and%20using%20WMS%20capabilities%20with%20PHP.html .