設置ko只在加載時計算並保存

Question

我有兩個敲除變量'Frequency'和'FrequencyText'，它們只是與頻率相關的文本描述。

在我的模型，我有：

self.Frequency = ko.observable(); 
    self.FrequencyText = ko.computed(function() { 
    var description; 
    switch (self.Frequency()) { 
     case "1": 
      description = "Once"; 
      break; 
     case "2": 
      description = "Twice"; 
      break; 
     case "3": 
      description = "Three Times"; 
      break; 
     default: 
      description = ""; 
      break; 
     } 
     return description; 
    }, this); 

    //Ajax call 
    GetAjax.done(function (data) { 
     self.Frequency(data.Frequency); 
    }); 

頻率由阿賈克斯加載和FrequencyText隨之移動。但是，如果用戶使用單選按鈕改變頻率，文本也會改變，我只希望在頻率保存到配置文件時更改頻率。所以我想在頁面加載時進行設置，並且如果他們保存了任何更改，就再次設置它。要做到這一點，我可以把它改成這樣的：

self.Frequency = ko.observable(); 
self.FrequencyText = ko.observable(); 


GetAjax.done(function (data) { 
     self.Frequency(data.Frequency); 
     self.FrequencyText(ko.computed(function() { 
     var description; 
      switch (self.Frequency()) { 
      case "1": 
       description = "Once"; 
       break; 
      case "2": 
       description = "Twice"; 
       break; 
      case "3": 
       description = "Three Times"; 
       break; 
      default: 
       description = ""; 
       break; 
      } 
      return description; 
      }, this)); 
    }); 

因此，它只能從JSON數據集（等負載），但是標識要重複所有的代碼在保存功能非常新的頻率。

我試圖離開ko.computed功能訪問Ajax像第一個例子，只是把它傳遞參數上載和提交更新它喜歡：

self.FrequencyText = ko.computed(function (newFrequency) { 
     //switch logic 
    }); 

但它說我有使用write：語句來使用參數。這就是我陷入困惑並來到這裏的地步。有關如何清理這一點的任何幫助？

Answer 1

在這種情況下，我不會使用計算的，而是通過標準函數手動更新的observable。

self.Frequency = ko.observable(); 
self.FrequencyText = ko.observable(""); 

GetAjax.done(function (data) { 
    self.Frequency(data.Frequency); 
    self.UpdateFrequencyText(data.Frequency); 
}); 

self.UpdateFrequencyText = function(frequency){ 
    var description; 
    switch (frequency) { 
     case "1": 
      description = "Once"; 
      break; 
     case "2": 
      description = "Twice"; 
      break; 
     case "3": 
      description = "Three Times"; 
      break; 
     default: 
      description = ""; 
      break; 
    } 
    self.FrequencyText(description); 
}