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Wrap Ajax Operations in Widgets

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Implementing and using CompoundWidgets


In this section I’ll describe how to build compound widgets and use them. For the time being, here’s a commented CompoundWidget demo TG widget’s package. To install:

$ tar xvjf compounddemo.X.Y.tar.bz2
$ cd compounddemo
$ [sudo] python develop
$ tg-admin toolbox

And watch the examples at the toolbox’s widget browser. You can also download & install one of the provided eggs:

$ [sudo] easy_install compounddemo-X.Y-py2.N.egg
$ tg-admin toolbox

How was the egg built?

tg-admin can create the skeleton of a widget’s egg like this:

tg-admin quickstart -t tgwidget compounddemo

It’s the best way to reuse widgets among projects and to modularize your apps for easier maintenance. Best of all, they are easily re-distributed.

Once you install the resulting egg just import the widgets in your app and enjoy.

from compounddemo import MyCompound

w = MyCompound()

Example project

This demo widget’s package aims to show how to create a custom CompoundWidget and a CompoundFormField for reusing view code amongst templates and forms.

It covers:

How to define child widget’s (which, of course, can also be compound). How to initialize them at the constructor to implement a facade pattern. How to override their params and value at display time.

It doesnt cover (yet):

How to deal with input conversion/facading. Take a look at the SelectShuttle’s code for an example:


When to choose a CompoundWidget or a CompoundFormField as a base class?


You should use a CompoundFormField whenever the widget is intended for use in a form, this is, a widget that we expect to generate input for our app inside a form that’s going to be submitted.

Use a CompoundWidget otherwise, this is, widgets like a an Ajax search field or any other kind of widget that might generate input but noy by means of form submission, like in AJAX requests.

Feel free to use and modify this code for any purpose in any way you like.