Programming Social Applications

POST Request

For the most part, HTTP POST requests are used to update existing resources on a server. You will be making a request to a service and passing along a POST payload, which the server then uses to denote the update resource or hold the content to be updated.

In PHP, we can use cURL to issue a POST request:

<?php
$url = 'http://www.example.com/request.php';
$postvals = 'firstName=John&lastName=Smith';

$ch = curl_init($url);
$options = array(
   CURLOPT_CUSTOMREQUEST => 'POST',
   CURLOPT_URL => $url,
   CURLOPT_POST => 1,
   CURLOPT_POSTFIELDS => $postvals,
   CURLOPT_RETURNTRANSFER => 1
);
curl_setopt_array($ch, $options);
$response = curl_exec($ch);
curl_close($ch);
?>

As with the GET request, we are making the call to a specified URL, but this time we are creating a POST string that we will send. In addition to the cURL options from the GET request, we use CURLOPT_CUSTOMREQUEST and CURLOPT_POST to state that we want to make a POST request and CURLOPT_POSTFIELDS to attach the data to send in the POST.

In Python, we can once again use urllib for the POST request:

import urllib

url = 'http://www.example.com/request.py'
postvals = {'first_name': 'John', 'last_name': 'Smith'}

params = urllib.urlencode(postvals)
f = urllib.urlopen(url, params)
response = f.read()

As with the GET request, we are making the request to a specific URL. This time, though, we create the object that we want to POST, encode it, and pass it along when we call urlopen(...).