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Represents a trigger property that can fire events and notify listeners. Unlike other Property types, a trigger does not store a persistent value. It emits an event when fire() is called.

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Fields

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addListener

Registers a listener that is invoked when the trigger fires. 
local vmi = context:viewModel()
if vmi then
  local cannon = vmi:getTrigger('cannon')
  if cannon then
    cannon:addListener(function()
      print("cannon fired!")
    end)

    cannon:fire()
  end
end

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removeListener

Removes a previously registered listener. Always remove listeners when they are no longer needed to avoid leaks. 
function init(self: MyNode, context: Context): boolean
  local vmi = context:viewModel()
  if vmi then
    local cannon = vmi:getTrigger('cannon')
    if cannon then
      self.cannon = cannon
      self.onCannonFired = onCannonFired
      cannon:addListener(onCannonFired)
    end
  end

  return true
end

function removeCannonListener(self: MyNode)
  if self.cannon then
    self.cannon:removeListener(self.onCannonFired)
  end
end

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Methods

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fire

Fires the trigger and notifies all registered listeners. 
local vmi = context:viewModel()
if vmi then
  local cannon = vmi:getTrigger('cannon')
  if cannon then
    cannon:addListener(function()
      print("cannon fired!")
    end)

    cannon:fire()
  end
end