Class: Listener

Inherits:
Object show all
Defined in:
lib/volt/reactive/events.rb

Overview

A listener gets returned when adding an ‘on’ event listener. It can be used to clear the event listener.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(klass, event, scope_provider, callback) ⇒ Listener

Returns a new instance of Listener.



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# File 'lib/volt/reactive/events.rb', line 10

def initialize(klass, event, scope_provider, callback)
  @klass = klass
  @event = event
  @scope_provider = scope_provider
  @callback = callback

  if DEBUG && RUBY_PLATFORM == 'opal'
    # puts "e: #{event} on #{klass.inspect}"
    @@all_events ||= []
    @@all_events << self

    # counts = {}
    # @@all_events.each do |ev|
    #   scope = (ev.scope_provider && ev.scope_provider.scope) || nil
    #
    #   # puts `typeof(scope)`
    #   if `typeof(scope) !== 'undefined'`
    #     counts[scope] ||= 0
    #     counts[scope] += 1
    #   end
    # end
    #
    # puts counts.inspect

    `window.total_listeners = window.total_listeners || 0;`
    `window.total_listeners += 1;`
    `console.log(window.total_listeners);`
  end
end

Instance Attribute Details

#klass ⇒ Object (readonly)

Returns the value of attribute klass.



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# File 'lib/volt/reactive/events.rb', line 8

def klass
  @klass
end

#scope_provider ⇒ Object (readonly)

Returns the value of attribute scope_provider.



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# File 'lib/volt/reactive/events.rb', line 8

def scope_provider
  @scope_provider
end

Instance Method Details

#call(*args) ⇒ Object 



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# File 'lib/volt/reactive/events.rb', line 48

def call(*args)
  if @removed
    # puts "Triggered on a removed event: #{@event}"
    return
  end

  if @klass.reactive?
    # Update the reactive value's current value to let it know it is being
    # followed.
    @klass.update_followers if @klass.respond_to?(:update_followers)
  end

  @callback.call(*args)
end

#inspect ⇒ Object 



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# File 'lib/volt/reactive/events.rb', line 91

def inspect
  "<Listener:#{object_id} event=#{@event} scope=#{scope.inspect}#{' internal' if internal?}>"
end

#internal? ⇒ Boolean

Returns:



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# File 'lib/volt/reactive/events.rb', line 40

def internal?
  @internal
end

#remove ⇒ Object

Removes the listener from where ever it was created.



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# File 'lib/volt/reactive/events.rb', line 64

def remove
  if @removed
    # raise "event #{@event} already removed"
    puts "event #{@event} already removed"
    return
  end

  if DEBUG && RUBY_PLATFORM == 'opal'
    @@all_events.delete(self) if @@all_events

    `window.total_listeners -= 1;`
    `console.log("Rem", window.total_listeners);`
  end


  @removed = true
  @klass.remove_listener(@event, self)

  # We need to clear these references to free the memory
  @scope_provider = nil
  @callback = nil
  # @klass2 = @klass
  @klass = nil
  # @event = nil

end

#scope ⇒ Object 



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# File 'lib/volt/reactive/events.rb', line 44

def scope
  @scope_provider && scope_provider.respond_to?(:scope) && @scope_provider.scope
end