使用coffeescript在事件处理程序上使用闭包

Question

与此类似：Issue with Coffeescript comprehensions and closures

我知道我必须以某种方式使用闭包，但我无法弄清楚究竟是怎样的。我想添加事件处理程序，它使用字符串附加参数并使用类方法作为处理程序方法。

# Load all transport layers
@_transportLayers = {}
for protocolName, protocol of transportLayerProtocols
   @_transportLayers[protocolName] = new protocol(config)
   @_transportLayers[protocolName].on 'data', (e, protocolName) =>

        # HERE IS THE PROBLEM: 

        # This generic event handler should get the protocolName as argument
        # But the protocolName is always the last one.
        @eventHandler(e, protocolName)
        return

提前致谢。

Answer 1

您想要创建一个函数，该函数返回一个函数，关闭变量：

# Load all transport layers
@_transportLayers = {}

handlerCreater = (protocolName) =>
  (e) => @eventHandler(e, protocolName) 

for protocolName, protocol of transportLayerProtocols
  @_transportLayers[protocolName] = new protocol(config)
  @_transportLayers[protocolName].on 'data', handlerCreater protocolName