Class: LiveResource::ActiveRecord::Dependency

Inherits:
Dependency
  • Object
show all
Defined in:
lib/live_resource/activerecord/dependency.rb

Constant Summary collapse

DEFAULT_EVENTS = 
[:after_commit]

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(resource, model_class, proc, *events) ⇒ Dependency

Returns a new instance of Dependency.



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# File 'lib/live_resource/activerecord/dependency.rb', line 16

def initialize(resource, model_class, proc, *events)
  @model_class = model_class

  if !events.empty?
    @events = events
  else
    @events = DEFAULT_EVENTS
  end

  super(resource, model_class, proc)
end

Instance Attribute Details

#model_class ⇒ Object (readonly)

Returns the value of attribute model_class.



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# File 'lib/live_resource/activerecord/dependency.rb', line 14

def model_class
  @model_class
end

#resource ⇒ Object (readonly)

Returns the value of attribute resource.



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# File 'lib/live_resource/activerecord/dependency.rb', line 14

def resource
  @resource
end

Class Method Details

.accepts_target?(target) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/live_resource/activerecord/dependency.rb', line 10

def self.accepts_target?(target)
  !!(target < ::ActiveRecord::Base) # The < operator returns nil instead of false
end

Instance Method Details

#observe(event) ⇒ Object 



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# File 'lib/live_resource/activerecord/dependency.rb', line 32

def observe(event)
  # Declare variables in method scope so they're preserved in the block
  dependency          = self
  subscribed_events   = @events
  target              = @model_class
  class_name          = "Observer_#{@resource.name}_dependency_on_#{@model_class}_for_#{@events.join('_')}"

  # Construct a new observer class
  dependency_observer = Class.new(::ActiveRecord::Observer) do
    observe target

    # Give it a class name otherwise ActiveRecord will explode
    @_class_name = class_name
    class << self
      def name
        @_class_name
      end
    end

    # Create callback methods on the observer class for each subscribed event
    subscribed_events.each do |event_name|
      define_method(event_name) do |*args|
        dependency.invoke(args[0], event_name)
      end
    end
  end

  # Instantiating the observer class will make it hook itself up
  dependency_observer.send :new
end

#watch ⇒ Object 



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# File 'lib/live_resource/activerecord/dependency.rb', line 28

def watch
  @events.each { |event| observe event }
end