canoical方式計算正確的觀察到在CoffeeScript中

Question

我試着翻譯下面的代碼的CoffeeScript作爲一種實踐

function StateVM() { 
    var self = this; 

    self.state = ko.observable("stopped"); 
    self.counter = ko.observable(0); 
    self.timeStopped = ko.observable(new Date()); 
    self.timeStarted = ko.observable(new Date()); 
    self.currentTime = ko.observable(new Date()); 
    self.timeRunning = ko.computed(function(){ 
     var num = (self.currentTime() - self.timeStarted())/1000 >> 0; 
     return (num < 0) ? 0 : num; 
    }); 

    self.isStopped = ko.computed(function(){ 
     return (self.state() === "stopped"); 
    }); 

    self.isStarted = ko.computed(function(){ 
     return (self.state() === "running"); 
    }); 

$(document).ready(function(){ 
    var vm = new StateVM(); 
    ko.applyBindings(vm); 
}); 

現在我在這的CoffeeScript代碼，但我正在與問題自referentials @編譯進錯範圍：

obs = ko.observable 
cmp = ko.computed 

class StateVM 
    constructor: -> 
     state = obs "stopped" 
     counter = obs 0 
     timeStopped = obs new Date 
     timeStarted = obs new Date 
     currentTime = obs new Date 
     timeRunning = cmp -> 
      x = (@currentTime() - @timeStarted())/1000 >> 0 
      x < 0 ? 0 : x 

     isStopped = cmp -> @state() == "stopped" 
     isStarted = cmp -> @state() == "running" 

$ -> ko.applyBindings(new StateVM) 

是否有這樣做的一個典型方式是什麼？

Answer 1

好了...我知道了搜索一下工作：

https://groups.google.com/forum/?fromgroups=#!topic/knockoutjs/CTBLQthLGWU

我沒做兩件事情......一個是我沒有在構造函數聲明添加@和另一種是使用=>而不是->

obs = ko.observable 
cmp = ko.computed 

class StateVM 
    constructor: -> 
     @state = obs "stopped" 
     @counter = obs 0 
     @timeStopped = obs new Date 
     @timeStarted = obs new Date 
     @currentTime = obs new Date 
     @timeRunning = cmp => 
      x = (@currentTime() - @timeStarted())/1000 >> 0 
      x < 0 ? 0 : x 

     @isStopped = cmp => @state() == "stopped" 
     @isStarted = cmp => @state() == "running" 
     @start = (->) ; 
     @stop = (->) ; 

$ -> ko.applyBindings(new StateVM)