Class: Houston::Observer

Inherits:
Object
  • Object
show all
Defined in:
lib/houston/boot/observer.rb

Defined Under Namespace

Classes: Callback, CallbackOnce, MissingParamError, UnregisteredEventError, UnregisteredParamError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Observer

Returns a new instance of Observer.



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# File 'lib/houston/boot/observer.rb', line 9

def initialize
  @async = true
  clear!
end

Instance Attribute Details

#async ⇒ Object

Returns the value of attribute async.



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# File 'lib/houston/boot/observer.rb', line 3

def async
  @async
end

Instance Method Details

#clear! ⇒ Object 



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# File 'lib/houston/boot/observer.rb', line 62

def clear!
  @observers = {}
end

#fire(event, params = {}) ⇒ Object 



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# File 'lib/houston/boot/observer.rb', line 41

def fire(event, params={})
  assert_registered! event

  unless params.is_a?(Hash)
    raise ArgumentError, "params must be a Hash" unless params.respond_to?(:to_h)
    params = params.to_h
  end

  assert_registered_params! event, params
  assert_serializable! params
  params = ReadonlyHash.new(params)

  observers_of(event).each do |callback|
    callback.call params
  end
  observers_of(:*).each do |callback|
    callback.call event, params
  end
  nil
end

#observed?(event) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/houston/boot/observer.rb', line 36

def observed?(event)
  assert_registered! event
  observers_of(event).any?
end

#off(callback, &block) ⇒ Object 



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# File 'lib/houston/boot/observer.rb', line 26

def off(callback, &block)
  if block_given?
    event = callback
    callback = observers_of(event).detect { |callback| callback.block == block }
    return nil unless callback
  end
  observers_of(callback.event).delete callback
  nil
end

#on(event, options = {}, &block) ⇒ Object 



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# File 'lib/houston/boot/observer.rb', line 14

def on(event, options={}, &block)
  assert_registered! event
  observers_of(event).push Callback.new(self, event, options, block)
  nil
end

#once(event, options = {}, &block) ⇒ Object 



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# File 'lib/houston/boot/observer.rb', line 20

def once(event, options={}, &block)
  assert_registered! event
  observers_of(event).push CallbackOnce.new(self, event, options, block)
  nil
end