jquery-injector.coffee

@Injector =
  init: ->
    console.log("Initializing")
    @checkAndInjectjQuery()

  checkAndInjectjQuery: ->
    if jQuery?
      console.log("jQuery detected, checking version...")
      if @versionCompare(jQuery.fn.jquery, "2.0.3") < 0
        console.log("jQuery v#{jQuery.fn.jquery} too old, injecting 2.0.3...")
        @injectjQuery(true)
      else
        console.log("jQuery v#{jQuery.fn.jquery} is fine, using it.")
        @jq = window.jQuery
    else
      console.log("jQuery not found, injecting 2.0.3...")
      @injectjQuery(false)

  injectjQuery: (saveOriginal) ->
    script = document.createElement('script')
    script.src = "http://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"
    head = document.getElementsByTagName('head')[0]

    if saveOriginal
      @jq = $.noConflict(true)

    head.appendChild(script)

    @checkLoaded(saveOriginal)

  checkLoaded: (saveOriginal) ->
    window.setTimeout( =>
      if !jQuery?
        console.log("jQuery not yet loaded, retrying...")
        @checkLoaded(saveOriginal)
      else
        console.log("jQuery loaded: v#{jQuery.fn.jquery}")
        if saveOriginal
          temp = @jq
          @jq = $.noConflict(true)
          window.jQuery = temp
          window.$ = jQuery
        else
          @jq = jQuery

        @continueInitialization()
    , 500)

  continueInitialization: ->
    console.log("Do whatever you want in here.")

  versionCompare: (v1, v2) ->
    v1parts = v1.split('.')
    v2parts = v2.split('.')

    isValidPart = (x) ->
      (/^\d+$/).test(x)

    if !v1parts.every(isValidPart) || !v2parts.every(isValidPart)
      return NaN

    v1parts = v1parts.map(Number)
    v2parts = v2parts.map(Number)

    l = v1parts.length - 1
    for i in [0..l]
      if v2parts.length == i
        return 1

      if v1parts[i] == v2parts[i]
        continue

      else if v1parts[i] > v2parts[i]
        return 1

    if v1parts.length != v2parts.length
      return -1

    return 0