通过dom-repeat函数设置属性更改不会反映在UI中-Polymer [英] Property change not reflecting in UI when its set from dom-repeat's function - Polymer

问题描述

我有对象数组和一个属性，我的dom-repeat结构如下所示

I have array of objects and a property, my dom-repeat structure is like as below

     <template is="dom-repeat" items="{{arrayOfObj}}">              //first dom repeat      
       <span>[[myProperty]]<span> //here also its not updating      
        <template is="dom-if" if="[[_checkSomeCondition()]]">    //calling method from dom-if
          <span>[[myProperty]]<span>     //here its not getting updated value
        </template>
     </template>

我有一个财产

 properties:{
 myProperty:{
  type:Boolean
 }
}

每次重复执行dom-repeat时都会调用我的函数

my function is called each time when dom-repeat iterates

 _checkSomeCondition:function() {  //I'll check and set property
  if(some condition){
     this.myProperty = true;
     return true;
   }
   else{
     this.myProperty = false;
     return true;
   }
 console.log(this.myProperty); //I'll get the updated value on console
}

但是它在屏幕上没有改变！它将显示它在_checkSomeCondition内首次设置的任何数据！但是在控制台中更新

but its not changing in screen!! It will display whatever data it set first time inside _checkSomeCondition !! but in console its updating

为了进行测试，我插入了一个按钮，并在点击该按钮后渲染了所有dom-repeat之后，我调用了一些函数，当我更改值时，它会无处不在

For testing I inserted a button and after all dom-repeat rendered on tapping that button I called some function ,there when I changed value it get reflected everywhere

    this.myProperty = true;

但是当在dom-repeat调用的函数中更改值时为什么它不起作用?我尝试了所有三种更新对象的方法

but why its not working when value is changed inside a function which is called by dom-repeat?? I tried all 3 ways of updating a object

柱塞: https://plnkr.co/edit/iAStve97dTTD9cv6iygX?p=preview

推荐答案

通过this.myValue ='somevalue';设置变量.将不会更新绑定.

Setting a variable via this.myValue = 'somevalue'; won't update binding.

最好通过this.set('variablename', 'variablevalue');

通过this.variablename = 'variablevalue'; this.notifyPath('variablename'设置属性后，您还可以；

You could also, after setting a property via this.variablename = 'variablevalue'; this.notifyPath('variablename');

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