.. _tw_cookbook_jqueryajaxform:

JQuery AjaxForm Widget
======================


Installation
------------

::
  
  easy_install tw.jquery


Usage
-----

The AjaxForm widget supports the following parameters:

Mandatory Parameters:
~~~~~~~~~~~~~~~~~~~~~

* **id** The id of the form. The submit action of this form triggers
    the Ajax Request.
* **fields** The form fields. The fields could be a WidgetList object
    created like this:

.. code-block:: python

    from formencode import validators
    from tw.forms.fields import TextField, TextArea, CheckBox
    from tw.api import WidgetsList

    class CommentFields(WidgetsList):
        """The WidgetsList defines the fields of the form."""

        name = TextField(validator=validators.NotEmpty())
        email = TextField(validator=validators.Email(not_empty=True),
                        attrs={'size':30})
        comment = TextArea(validator=validators.NotEmpty())
        notify = CheckBox(label="Notify me")

* **action** The url for the controller method that would handle the
    Ajax Request.

Optional Parameters:
~~~~~~~~~~~~~~~~~~~~

* **target** This is the id of the element where the output of the
    request would be rendered. (*Default:* "output")
* **type** The method to use for the request, i.e. whether GET or
    POST. (*Default:* "POST")
* **dataType** The dataType of the response, i.e. whether XML, JSON or
    SCRIPT. (*Default:* "JSON")
* **beforeSubmit** The javascript function that should be called just
    before submitting the request. This could be helpful for doing
    javascript based validations if needed. (*Default:* None)
* **success** The javascript function that should be called if the
    request succeeds. (*Default:* None)
* **clearForm** Clears the form after sending the request. (*Default:*
    True)
* **resetForm** Resets the form after sending the request. (*Default:*
    True)
* **timeout** Time in ms before the request is timed out. (*Default:*
    3000)

A simple AjaxForm widget may be instantiated as::

    from tw.jquery import AjaxForm

    ajax_form = AjaxForm(id="myAjaxForm",
                        fields=CommentFields(),
                        target="output",
                        action="do_search")


The form can then be served up to the user via a controller method
like this::
  
   @expose('mypackage.templates.myformtemplate')
   def entry(self, **kw):
       pylons.c.form = myAjaxForm
       return dict(value=kw)

In your template you need to pickup your form from the template
context for rendering. Also create a target div ("output" in this
case) to display the output::

   ${tmpl_context.form(show_labels=True, value=value)}

And here is the resulting field when viewed from a browser:

.. image:: ../images/ajaxform1.png
    :alt: example AjaxForm

The template generates the necessary javascript code to send the Ajax
Request when the form is submitted. The controller code for generating
the response would be something like::

    @expose()
    @validate(ajax_form)
    def do_search(self, **kw):
        return "<p>Recieved Data:<br/>%(name)s<br/>%(email)s<br/>%(comment)s<br/>%(notify)s<br/></p>" % kw

The output would be rendered inside a div element called *output*,
which is the default target element. This is how the page looks like
after the form has been successfully submitted:

.. image:: ../images/ajaxform2.png
    :alt: example AjaxForm


.. todo:: Difficulty: Medium. Getting output as JSON and updating a data grid
