get a PHP delete variable

As stated by people above, PHP does not have a global variable to quickly access data in a DELETE request. Why, I do not know; it probably hasn't been as used as GET and POST historically.

You would have to check the request type using $_SERVER['REQUEST_METHOD'] and then retrieve the entire body using the php://input stream and extract your data from that. You could create a function that does this on every request and saves it in a global variable named $_DELETE if you would like to keep a similar look to your code (assuming you use $_POST and $_GET). You could even patch your PHP to do this and compiling your own version of PHP, but that would of course confuse people who try to run your code on another PHP installation :)

file_get_contents('php://input') should always give you the complete request body. Note that it may be readable only once. The bigger question is whether a DELETE request may contain a body, which seems to be something of an unanswered question, but will probably work.

I'd say sending the id in the body is somewhat RESTless though. The entity in question should be referred to by the URL as example.com/foo/42, so a DELETE request should say DELETE /foo/42, not DELETE /foo with the id in the request body.

You might have to look at reading the data directly from the php://input stream.

I knwo this is how you have to do it for PUT requests and some quick googling indicates the method works for DELETE as well.

See here for an example. The comment here says this method works for DELETE also.

Here is an interesting code sample that will help (from sfWebRequest.class.php of the symfony 1.4.9 framework altered slight for brevity):

public function initialize(...) 
{
  ... code ...

  $request_vars = array();
  if (isset($_SERVER['REQUEST_METHOD']))
  {
    switch ($_SERVER['REQUEST_METHOD'])
    {
      case 'PUT':
        if ('application/x-www-form-urlencoded' === $this->getContentType())
        {
          parse_str($this->getContent(), $request_vars );
        }
        break;

      case 'DELETE':
        if ('application/x-www-form-urlencoded' === $this->getContentType())
        {
          parse_str($this->getContent(), $request_vars );
        }
        break;
    }
  ... more code ...
}

public function getContent()
{
  if (null === $this->content)
  {
    if (0 === strlen(trim($this->content = file_get_contents('php://input'))))
    {
      $this->content = false;
    }
  }

  return $this->content;
}

This code sample puts the PUT or DELETE request parameters into the $request_vars array. A limitation appears to be that the form (if you are using one other the content-type header) must be 'application/x-www-form-urlencoded', some quick googling confirms this.