:LastChangedDate: $LastChangedDate$ :LastChangedRevision: $LastChangedRevision$ :LastChangedBy: $LastChangedBy$ Handling POSTs ============== All of the previous examples have focused on ``GET`` requests. Unlike ``GET`` requests, ``POST`` requests can have a request body - extra data after the request headers; for example, data representing the contents of an HTML form. Twisted Web makes this data available to applications via the :api:`twisted.web.server.Request ` object. Here's an example web server which renders a static HTML form and then generates a dynamic page when that form is posted back to it. Disclaimer: While it's convenient for this example, it's often not a good idea to make a resource that ``POST`` s to itself; this isn't about Twisted Web, but the nature of HTTP in general; if you do this in a real application, make sure you understand the possible negative consequences. As usual, we start with some imports. In addition to the Twisted imports, this example uses the ``cgi`` module to `escape user-enteredcontent `_ for inclusion in the output. .. code-block:: python from twisted.web.server import Site from twisted.web.resource import Resource from twisted.internet import reactor import cgi Next, we'll define a resource which is going to do two things. First, it will respond to ``GET`` requests with a static HTML form: .. code-block:: python class FormPage(Resource): def render_GET(self, request): return '' This is similar to the resource used in a :doc:`previous installment ` . However, we'll now add one more method to give it a second behavior; this ``render_POST`` method will allow it to accept ``POST`` requests: .. code-block:: python ... def render_POST(self, request): return 'You submitted: %s' % (cgi.escape(request.args["the-field"][0]),) The main thing to note here is the use of ``request.args`` . This is a dictionary-like object that provides access to the contents of the form. The keys in this dictionary are the names of inputs in the form. Each value is a list containing strings (since there can be multiple inputs with the same name), which is why we had to extract the first element to pass to ``cgi.escape`` . ``request.args`` will be populated from form contents whenever a ``POST`` request is made with a content type of ``application/x-www-form-urlencoded`` or ``multipart/form-data`` (it's also populated by query arguments for any type of request). Finally, the example just needs the usual site creation and port setup: .. code-block:: python root = Resource() root.putChild("form", FormPage()) factory = Site(root) reactor.listenTCP(8880, factory) reactor.run() Run the server and visit `http://localhost:8880/form `_ , submit the form, and watch it generate a page including the value you entered into the single field. Here's the complete source for the example: .. code-block:: python from twisted.web.server import Site from twisted.web.resource import Resource from twisted.internet import reactor import cgi class FormPage(Resource): def render_GET(self, request): return '' def render_POST(self, request): return 'You submitted: %s' % (cgi.escape(request.args["the-field"][0]),) root = Resource() root.putChild("form", FormPage()) factory = Site(root) reactor.listenTCP(8880, factory) reactor.run()