触发NG-模式。$格式化以编程方式运行 [英] Trigger ng-model.$formatters to run programatically

问题描述

我想使用 ngModel。$格式化 ，能够在一台服务器负载的依赖，尽快格式的数据。对于我来说，它需要加载一个查找表去从一种ID来另一个。 $ modelValue 商店一件事 $ viewValue 显示另一个。 pretty直接的东西。

诀窍是，如果没有加载我的查找表，我不能做格式化成$ viewValue。

在我的数据负载，我需要做到以下几点：

• ngModel。$ formatters.push（myFormatter）


• 告诉ngModel，开始从 $ modelValue管道 - ＆GT; $格式化 - ＆GT; $ viewValue

$渲染（）不工作，这只是移动从 $ viewValue 的值到UI控件。
$ rollbackViewValue（）看起来很有希望，但是这只是一个不稳定的版本（的 1.3.0-beta.18 ）。

code样品：<​​/ P>

  mappingTable.load（）。然后（功能（数据）{
  mappingData =数据;
  ngModel $ formatters.push（myFormatter）。 //需要mappingData以功能
  // TODO：告诉ngModel运行到$ $现有的格式化modelValue计算新的$ viewValue和$使其
  //ngModel.$render（）//不工作，只放$ viewValue中的DOM元素。
}）;
 

解决方案

纵观code代表ngModelController，看来你偶然发现（设置 $ modelValue 到任何东西比目前的实际模型值等）是这样做的接受的方式。正如你所说，你设置的值不使用：它只是触发更新。首先检查其电流值，以确保它实际上改变（或使用的可能性极小值）。

 如果（ngModel。$ modelValue =='巴'）
    ngModel $ modelValue ='富'。
其他
    。ngModel $ modelValue ='吧';
 

下面是一个<一个href=\"http://stackoverflow.com/questions/13995414/have-formatters-be-called-when-view-is-first-populated\">related问题。

此外，还有看起来像一个正式的积极拉动申请 这样做的方式是即将到来的。

它的工作原理的原因是ngModelController设置了一个 $观看运行每个消化周期比较 $ modelValue 该值NG-模式势必。如果它们不匹配时，会触发 $格式化管道。

I'd like a custom control that uses ngModel.$formatters to be able to format data as soon as a server dependency loads in. In my case, it needs to load a lookup table to go from one kind of id to another. $modelValue stores one thing $viewValue displays another. Pretty straight-forward stuff.

The trick is that if my lookup table isn't loaded, I can't do the formatting into a $viewValue.

Once my data loads, I need to do the following:

• ngModel.$formatters.push(myFormatter)
• Tell ngModel to start the pipeline from $modelValue -> $formatters -> $viewValue

$render() doesn't work, this just moves the value from $viewValue into the UI control. $rollbackViewValue() looks promising, but that's only in an unstable version (1.3.0-beta.18).

Code Sample:

mappingTable.load().then(function(data){
  mappingData = data;
  ngModel.$formatters.push(myFormatter); // needs mappingData in order to function
  // TODO: Tell ngModel to run the existing $modelValue through $formatters to calculate a  new $viewValue and $render it
  //ngModel.$render() // doesn't work, only puts the $viewValue in the DOM element.
});

解决方案

Looking at the code for ngModelController, it appears that what you stumbled upon (setting $modelValue to anything other than the current actual model value) is the accepted way to do this. As you say, the value you set is not used: it just triggers the update. Check its current value first to make sure it actually changes (or use a very unlikely value).

if (ngModel.$modelValue == 'bar')
    ngModel.$modelValue = 'foo';
else
    ngModel.$modelValue = 'bar';

Here is a related question.

Also, there is an active pull request that looks like an "official" way of doing this is forthcoming.

The reason it works is that ngModelController sets up a $watch that runs every digest cycle that compares $modelValue to the value that ng-model is bound to. If they don't match, it triggers the $formatters pipeline.

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