107 lines
2.5 KiB
Text
107 lines
2.5 KiB
Text
= Hooks
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<em>Generic hooks with callbacks for Ruby.</em>
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== Introduction
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_Hooks_ lets you define hooks declaratively in your ruby class. You can add callbacks to your hook, which will be run as soon as _you_ run the hook!
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It's almost like ActiveSupport::Callbacks but 76,6% less complex. Instead, it is not more than 60 lines of code, one method compilation, no +method_missing+ and no magic.
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Also, you may pass additional arguments to your callbacks when invoking a hook.
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== Example
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Let's take... a cat.
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require 'hooks'
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class Cat
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include Hooks
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define_hook :after_dinner
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Now you can add callbacks to your hook declaratively in your class.
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after_dinner do
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puts "Ice cream for #{self}!"
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end
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after_dinner :have_a_desert # => refers to Cat#have_a_desert
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def have_a_desert
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puts "Hell, yeah!"
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end
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This will run the block and <tt>#have_a_desert</tt> from above.
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cat.run_hook :after_dinner
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# => Ice cream for #<Cat:0x8df9d84>!
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Hell, yeah!
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Callback blocks and methods will be executed with instance context. Note how +self+ in the block refers to the Cat instance.
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== Inheritance
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Hooks are inherited, here's a complete example to put it all together.
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class Garfield < Cat
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after_dinner :want_some_more
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def want_some_more
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puts "Is that all?"
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end
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end
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Garfield.new.run_hook :after_dinner
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# => Ice cream for #<Cat:0x8df9d84>!
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Hell, yeah!
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Is that all?
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Note how the callbacks are invoked in the order they were inherited.
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== Options for Callbacks
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You're free to pass any number of arguments to #run_callback, those will be passed to the callbacks.
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cat.run_hook :before_dinner, cat, Time.now
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The callbacks should be ready for receiving parameters.
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before_dinner :wash_pawns
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before_dinner do |who, when|
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...
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end
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def wash_pawns(who, when)
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Not sure why a cat should have ice cream for dinner. Beside that, I was tempted naming this gem _hooker_.
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== Installation
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gem install hooks
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== Anybody using it?
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* Hooks is already used in [Apotomo:http://github.com/apotonick/apotomo], a hot widget framework for Rails. Look at +lib/apotomo/widget.rb+ for examples and into +lib/apotomo/tree_node.rb+ to learn how modules-driven code might benefit from hooks.
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== Similar libraries
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* http://github.com/nakajima/aspectory
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* http://github.com/auser/backcall
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* http://github.com/mmcgrana/simple_callbacks
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== License
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Copyright (c) 2010, Nick Sutterer
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Released under the MIT License.
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