Class: Reacto::Operations::DependOn

Inherits:
Object
  • Object
show all
Defined in:
lib/reacto/operations/depend_on.rb

Instance Method Summary collapse

Constructor Details

#initialize(trackable, key: :data, accumulator: nil) ⇒ DependOn

Returns a new instance of DependOn.



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# File 'lib/reacto/operations/depend_on.rb', line 7

def initialize(trackable, key: :data, accumulator: nil)
  @key = key
  @trackable =
    if accumulator.nil?
      trackable.first
    else
      trackable.inject(NO_VALUE, accumulator)
    end

  @lock = Mutex.new

  @close = false
  @error = nil
end

Instance Method Details

#buffer ⇒ Object 



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# File 'lib/reacto/operations/depend_on.rb', line 22

def buffer
  @buffer ||= []
end

#call(tracker) ⇒ Object 



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# File 'lib/reacto/operations/depend_on.rb', line 55

def call(tracker)
  value = ->(v) do
    if @result.nil?
      @lock.synchronize do
        buffer << v

        check_ready_and_track(tracker)
      end
    else
      tracker.on_value(
        OpenStruct.new({ value: v }.merge(@key => @result))
      )
    end
  end

  error = ->(e) do
    if @result.nil?
      @lock.synchronize do
        @error = e

        check_ready_and_track(tracker)
      end
    else
      tracker.on_error(e)
    end
  end

  close = -> do
    if @result.nil?
      @lock.synchronize do
        @close = true

        check_ready_and_track(tracker)
      end
    else
      tracker.on_close
    end
  end

  Subscriptions::OperationSubscription.new(
    tracker,
    value: value,
    error: error,
    close: close
  )
end

#check_ready_and_track(tracker) ⇒ Object 



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# File 'lib/reacto/operations/depend_on.rb', line 42

def check_ready_and_track(tracker)
  depend_value = ->(v) { @result = v }
  depend_error = ->(e) { flush(e) }
  depend_close = -> { flush }

  if @subscription.nil?
    @tracker = tracker
    @subscription = @trackable.on(
      value: depend_value, error: depend_error, close: depend_close
    )
  end
end

#flush(error = nil) ⇒ Object 



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# File 'lib/reacto/operations/depend_on.rb', line 26

def flush(error = nil)
  unless error.nil?
    @tracker.on_error(error)
    return
  end

  buffer.each do |val|
    @tracker.on_value(
      OpenStruct.new({ value: val }.merge(@key => @result))
    )
  end

  @tracker.on_close if @close
  @tracker.on_error(@error) if @error
end