淘汰賽擴展器不能同時工作

Question

我有一些擴展代碼，我希望能夠同時使用。一旦我嘗試用範圍擴展數字，問題就不起作用。

ko.extenders.numeric = function (target, precision) { 
      //create a writable computed observable to intercept writes to our observable 
      var result = ko.pureComputed({ 
       read: target, //always return the original observables value 
       write: function (newValue) { 
        var current = target(), 
         roundingMultiplier = Math.pow(10, precision), 
         newValueAsNum = isNaN(newValue) ? 0 : parseFloat(+newValue), 
         valueToWrite = Math.round(newValueAsNum * roundingMultiplier)/roundingMultiplier; 

        //only write if it changed 
        if (valueToWrite !== current) { 
         target(valueToWrite); 
        } else { 
         //if the rounded value is the same, but a different value was written, force a notification for the current field 
         if (newValue !== current) { 
          target.notifySubscribers(valueToWrite); 
         } 
        } 
       } 
      }).extend({ notify: 'always' }); 

      //initialize with current value to make sure it is rounded appropriately 
      result(target()); 

      //return the new computed observable 
      return result; 
     }; 

這裏是另一個擴展...

ko.extenders.range = function (target, intRange) { 
     //create a writeable computed observable to intercept writes to our observable 
     var result = ko.computed({ 
      read: target, //always return the original observables value 
      write: function (newValue) { 
       alert(target()); 
       var current = target(), 
        newValueAsNum = isNaN(newValue) ? 0 : parseInt(+newValue, 10), 
        valueToWrite = newValueAsNum; 

       if (newValueAsNum < intRange.min) { 
        valueToWrite = intRange.min; 
       } 

       if (newValueAsNum > intRange.max) { 
        valueToWrite = intRange.max; 
       } 
       //only write if it changed 
       if (valueToWrite !== current) { 
        target(valueToWrite); 
       } else { 
        //if the tested value is the same, but a different value was written, force a notification for the current field 
        if (newValue !== current) { 
         target.notifySubscribers(valueToWrite); 
        } 
       } 
      } 
     }).extend({ notify: 'always' }); 

     //initialize with current value to make sure it is rounded appropriately 
     result(target()); 

     //return the new computed observable 
     return result; 
    }; 

這裏是我的小提琴https://jsfiddle.net/xequence/0nL09w55/

這裏是違規實施

var InitializePanelsApplicantViewModel = function() { 
     this.CoverageLimit = ko.observable('').extend({required: true}).extend({numeric: 2}), 
     this.CoverageLimitFailWhyCry = ko.observable('').extend({required: true}).extend({numeric: 2}).extend({range : 500}); 
     };   

     $(function(){ 
var masterVM = (function() { 
this.InitializePanelsApplicantViewModel = new InitializePanelsApplicantViewModel(); 
})(); 

ko.applyBindings(masterVM); 
}); 

Answer 1

請參閱this fiddle我認爲這顯示了你想要的行爲。

我已經簡化的例子的位和進行了如下修改：

• 的範圍擴展期待一個對象與min 和max性質。我改變了這個，所以調用extend傳遞對象而不僅僅是一個數字值。

• 數字擴展器使用的是ko.pureComputed而不是ko.computed。由於該功能有副作用，我認爲你應該使用ko.computed。有關詳情，請參閱knockout.js docs page。

• 範圍擴展器使用的是parseInt，它覆蓋了在數字擴展器中完成的任何舍入。兩者現在都使用parseFloat。