Apotomo 1.1.1 Released – Simpler Bubbling Events!

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We released a new version for Apotomo, the widget framework for Rails. Here’s a brief overview what “1.1.1”:https://github.com/apotonick/apotomo gives us.

h3. What’s new?

* *Inheritance for @#responds_to_event@* Observers are now inherited, which makes it simpler to work with inheritance.
* *Easier global observers* @#responds_to_event@ got a new option to simplify attaching observers to root (or any other widget).

h3. Inheritance for observers

Say we had a widget for listing todo items.

class TodosWidget  :update
  
  def display
    @todos = Todo.find(:all)
    render
  end

  def update(evt)
    replace :state => :display
  end
end

As soon as a @:newTodo@ event is met the widget will redraw.

h3. Widgets and OOP

Now if we need another widget *showing completed todos*, only, we can use inheritance.

class CompletedTodosWidget < TodosWidget
  def display
    @todos = Todo.completed
    render
  end
end

All we have to overwrite is the @#display@ state to grab completed todos. Everything else
* the @responds_to_event@ observer
* the remaining state methods
* and the views
are *_inherited_* from @TodosWidget@!

In former versions, you had to _redefine_ the observers in the derived class, which was the opposite of cool.

h3. Simple global observers

Often, there are widgets on the same tree level.

class DashboardController < ApplicationController

  has_widgets do |root|
    root << widget(:todos)
    root << widget(:todo_form)

Both widgets are attached to @root@ – they’re hierarchically on the same level.

The @todo_form@ widget triggers an event when there’s a new submission.

class TodoFormWidget  :process
  
  def process(evt)
    # save the new todo
    trigger :newTodo
  end

The event will bubble from @todo_form@ to @root@ – how could the @todos@ widget observe that event in order to update?

h3. A new option for @responds_to_event@

Well, attach the observer to @root@ – you will surely catch every event there (except if you @stop!@ it somewhere),

class TodosWidget  :update,
    :passing => :root

The @:passing@ option does exactly that. As soon as the @:newTodo@ event is encountered in @root@, it will trigger the @TodosWidget#update@ state. It’s so simple.

Note that you can attach observers to _any_ widget in the tree using @:passing@.

h3. Go for it!

Let us know how those tiny changes work for you. Cheers!

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