Class: Puppeteer::Bidi::Core::EventEmitter

Inherits:
Object
  • Object
show all
Defined in:
lib/puppeteer/bidi/core/event_emitter.rb,
sig/puppeteer/bidi/core/event_emitter.rbs

Overview

EventEmitter provides event subscription and emission capabilities Similar to Node.js EventEmitter but simpler

Instance Method Summary collapse

Constructor Details

#initialize ⇒ EventEmitter

Returns a new instance of EventEmitter.



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# File 'lib/puppeteer/bidi/core/event_emitter.rb', line 11

def initialize
  @listeners = Hash.new { |h, k| h[k] = [] }
  @disposed = false
end

Instance Method Details

#dispose ⇒ void

This method returns an undefined value.

Dispose the event emitter



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# File 'lib/puppeteer/bidi/core/event_emitter.rb', line 85

def dispose
  @disposed = true
  @listeners.clear
end

#disposed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/puppeteer/bidi/core/event_emitter.rb', line 91

def disposed?
  @disposed
end

#emit(event, data = nil) ⇒ void

This method returns an undefined value.

Emit an event to all registered listeners

Parameters:

  • event (Symbol, String)
  • data (Object) (defaults to: nil) 


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# File 'lib/puppeteer/bidi/core/event_emitter.rb', line 71

def emit(event, data = nil)
  return if @disposed
  listeners = @listeners[event.to_sym].dup
  listeners.each do |listener|
    begin
      listener.call(data)
    rescue => e
      warn "Error in event listener for #{event}: #{e.message}\n#{e.backtrace.join("\n")}"
    end
  end
end

#off(event, &block) ⇒ void

This method returns an undefined value.

Remove an event listener

Parameters:

  • event (Symbol, String) 


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# File 'lib/puppeteer/bidi/core/event_emitter.rb', line 46

def off(event, &block)
  event_sym = event.to_sym
  if block
    @listeners[event_sym].delete(block)
  else
    @listeners.delete(event_sym)
  end
  self
end

#on(event) {|arg0| ... } ⇒ EventEmitter

Register an event listener

Parameters:

  • event (Symbol, String)

Yields:

Yield Parameters:

  • arg0 (Object)

Yield Returns:

  • (void)

Returns:



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# File 'lib/puppeteer/bidi/core/event_emitter.rb', line 20

def on(event, &block)
  return self if @disposed

  @listeners[event.to_sym] << block
  self
end

#once(event) {|arg0| ... } ⇒ EventEmitter

Register a one-time event listener

Parameters:

  • event (Symbol, String)

Yields:

Yield Parameters:

  • arg0 (Object)

Yield Returns:

  • (void)

Returns:



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# File 'lib/puppeteer/bidi/core/event_emitter.rb', line 31

def once(event, &block)
  return self if @disposed

  wrapper = lambda do |*args|
    off(event, &wrapper)
    block.call(*args)
  end
  on(event, &wrapper)
  self
end

#remove_all_listeners(event = nil) ⇒ void

This method returns an undefined value.

Remove all listeners for an event or all events

Parameters:

  • event (?(Symbol | String), nil) (defaults to: nil) 


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# File 'lib/puppeteer/bidi/core/event_emitter.rb', line 59

def remove_all_listeners(event = nil)
  if event
    @listeners.delete(event.to_sym)
  else
    @listeners.clear
  end
end