Flirt

This Ruby gem is a brutally simple take on the observer pattern.

Flirt acts as a single point to which events can be sent and listeners can be registered, in order to promote extreme decoupling between components.

Installation

Add this line to your application's Gemfile:

gem 'flirt'

And then execute:

$ bundle

Or install it yourself as:

    $ gem install flirt

Usage

To publish an event:

event_data = { fruit: 'apple' }
Flirt.publish :picked, event_data

To subscribe:

class MyListener
    def initialize
        Flirt.subscribe self, :picked, with: :picked_callback
    end

    def picked_callback(event_data)
        puts "The #{event_data[:fruit]} has been picked"
    end
end

To unsubscribe:

    Flirt.unsubscribe self, :picked, with: :picked_callback
end

Syntactic sugar for subscription and unsubscription has been provided in the form of a module:

class MyListener
    include Flirt::Listener

    def initialize
        subscribe_to :picked, with: :picked_callback
    end

    def before_destroy
        unsubscribe_from :picked, with: :picked_callback
    end

    def picked_callback(event_data)
        puts "The #{event_data[:fruit]} has been picked"
    end
end

or even:

class MyListener
    extend Flirt::Listener

    subscribe_to :picked, with: :picked_callback

    def self.picked_callback(event_data)
        puts "The #{event_data[:fruit]} has been picked"
    end
end

unsubscribe_from can technically be used in the class context, but probably doesn't have as much use.

Flirt defaults to 'enabled'. Switch Flirt off:

Flirt.disable

And back on again:

Flirt.enable

Enabled status affects publishing only, listeners can still be added and will be remembered. No listeners will be removed.

Disable only a set of events:

Flirt.disable only: [:pancake_cooked, :picked]

Enable only a set of events:

Flirt.enable only: [:topping_added, :pancake_flipped]

Disabling and enabling sets of events is not cumulative. The new set of events will overwrite all previous calls. For example:

Flirt.disable only: [:pancake_cooked, :picked]
Flirt.disable only: [:flipped]

The above code will leave only :flipped disabled.

Flirt.enable only: [:flipped, :picked]
Flirt.disable only: [:flipped]

The above code will also leave only :flipped disabled.

Calling Flirt.enable or Flirt.disable will clear any previously set enabled or disabled events.

Clear all listeners:

Flirt.clear

This operation cannot be undone.

Contributing

1. Fork it ( https://github.com/[my-github-username]/flirt/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request