Apotomo is a stateful widget component framework for Rails.
A stateful WHAT?
Well, you know that. In Rails, people tend to have fat controllers. One controller action renders the complete page. While many programmers try to separate their code into helpers, controller actions, RJS logic and partials, it is still the controller that has to care about when to update what, and how!
In Apotomo, it is the opposite. Widgets are small, autonomous components that look and feel like controllers. These tiny monsters listen to events and thus keep updating themselves on the page via AJAX. However, there’s no JavaScript for you - they’re pure Ruby.
Let’s use the famous and tiresome counter example.
class CounterCell < Apotomo::StatefulWidget transition :from => :display, :to => :increment def display respond_to_event :counterClick, :with => :increment @count = 0 render # renders display.html.erb end def increment @count += 1 # @count is simply there - that's stateful. render :view => :display end end
Since this widget calls render it surely needs a view.
<!-- I'm display.html.erb --> <h1><%= @count %></h1> <%= link_to_event "Increment me!", :type => :counterClick %>
We now plug the widget in a page.
class ExistingController < ApplicationController include Apotomo::ControllerHelper def some_action # do what you want... use_widgets do |root| root << cell(:counter, :display, 'my_first_counter') end end end
As soon as the widget is rendered it will jump to its :display state which initializes the counter and renders itself.
Speaking of rendering: how do we place the widget in our controller?
<!-- I'm some_action.html.erb --> <p> <%= render_widget 'my_first_counter' %>
Ok, so this renders the widget in our controller page.
When clicking the link it updates automatically on the screen showing the incremented value. Wow.
Yes, it is.
Apotomo got a load of features.
- Composability
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Widgets can range from small standalone components to nested widget trees like dashboards or forms. Remember that each widget can have any number of children.
- Bubbling events
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Widgets can trigger events and watch out for them. While events bubble up from their triggering source to root they can be observed, providing a way to implement loosely coupled, distributable components.
- Deep Linking
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Apotomo deals with deep links (or url fragments) out-of-the-box while using SWFAddress. Components that register for deep linking will update as soon as the deep link changes. That makes your application back-button-safe!
- Testing
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Needless to say that it is simply easier to test small components instead of fat do-it-all controllers.
Give it a try- you will love the power and simplicity of real stateful components!
Please visit apotomo.de, the official project page with lots of examples. Join the mailing list and visit us in the IRC channel. More information is here.
Copyright © 2007-2010 Nick Sutterer <apotonick@gmail.com>
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