GET / POST / PUT Using PHP

The simplest way by far to do a GET in PHP (if you just want the return contents and don't care about the headers) is to use the file_get_contents. It's useful for getting the contents of a file quickly, or the contents of a web page. For example this method, from lab 2, retrieves data from S3.


function queryS3($path) {
  $contents = file_get_contents('http://s3.amazonaws.com/cs462-data/' . $path);

  return $contents;
}



Doing an HTTP POST, I use the cURL library. If you've never used curl before, there's a slight learning curve for doing a POST. I was able to figure it out after looking at a couple samples (the PHP documentation isn't much help). The key is creating an associative array from your POST data fields.

Here's an example from Lab 3, where my submit script (which is actually a Submit object) finally submits the idea to the submit server.


function sendToSubmitAppServer() {
  $url = "http://sslb-p.webappwishlist.com:8080/submit";
  $useragent="Johns Web Service Server, version 7";

  $data = array();
  $data['domain'] = $this->domain;
  $data['name'] = $this->name;
  $data['idea'] = $this->idea;

  $ch = curl_init();
  curl_setopt($ch, CURLOPT_USERAGENT, $useragent);
  curl_setopt($ch, CURLOPT_URL,$url);
  curl_setopt($ch, CURLOPT_POST, 1);
  curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
  $result = curl_exec ($ch);
  curl_close ($ch);
}


Doing HTTP PUT requests was a little more tricky, because I could send PHP doesn't offer a straightforward way of specifying the body of a PUT request, specifically where the body comes from a local string variable. I found a solution here (it basically says all the stuff I just said, with a code example. Here's my code example from lab 4, where I'm sending the XML data file to SQS. I can't be sure that it works, as I don't know how to test if something was sent to the queue. I'll update this example if I find any errors during the next couple days.


function submitToQueue($xml) {
  $url = "http://queue.amazonaws.com/A3N3IV5XJH079S/processing";
  $useragent="Distributed Systems/v3.4 (compatible; Mozilla 7.0; MSIE 8.5; http://classes.eclab.byu.edu/462/)";

  $fh = fopen('php://memory', 'rw');
  fwrite($fh, $xml);
  rewind($fh);

  $ch = curl_init();
  curl_setopt($ch, CURLOPT_USERAGENT, $useragent);
  curl_setopt($ch, CURLOPT_INFILE, $fh);
  curl_setopt($ch, CURLOPT_INFILESIZE, strlen($xml));
  curl_setopt($ch, CURLOPT_TIMEOUT, 10);
  curl_setopt($ch, CURLOPT_PUT, 1);
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

  $result = curl_exec($ch);
  curl_close($ch);
  fclose($fh);
}


It's opening a memory stream like it would a file stream, and then uses the CURLOPT_INFILE to specify the data to be sent in the body. I ran into a situation like this before (not while using PUT) which I solved by actually writing data to a file and then passing the file back in. Talk about a hack...