将功能作为参数传递给coffeescript

Question

I'm trying to utilize the CoffeeScript Cookbook's debounce function , but I'm struggling with how to pass the function.

Here's my code:

$('#inputID').on 'keyup', =>
    query = $('#inputID').val()
    func = => console.debug(query)
    Debounce.debounceFunction func, 300, false

The debounce function is called and the 300 and the "false" are passed just fine, but the 'func' doesn't execute.

In a separate file I have:

root = exports ? this

class Debouncer
  debounceFunction: (func, threshold, execAsap) ->
    timeout = null
    (args...) ->
        obj = this
        delayed = ->
            func.apply(obj, args) unless execAsap
            timeout = null
        if timeout
            clearTimeout(timeout)
        else if (execAsap)
            func.apply(obj,args)
        timeout = setTimeout delayed, threshold || 100

root.Debounce = new Debouncer()

Answer 1

The example in the Cookbook is misleading. You want the debouncer to return the function when registering the event handler. That way your timeout logic is run every time a keyup event occurs.

$('#inputID').on 'keyup', Debounce.debounceFunction(func, 300, false)

Try it on jsfiddle

Answer 2

It seems to me that with debounce you're just defining the function. you'll have to execute it too...

func = ->
  query = $('#inputID').val()
  console.debug(query)

debounceFunc = debounce func, 300, false

$('#inputID').on 'keyup', -> debounceFunc()