如何使用$ watchGroup与对象的相等或深观看该组中的属性？

问题描述

我想只要3范围内的变量已经改变了指令重新呈现HTML。前两个都只是整数，第三个是一个数组。

我们有 $ watchGroup 看几个变量，我们有 $观看与 objectEquality 作为第三个参数，我们有 $ watchCollection 这就好比 $观看，但与 objectEquality 暗示的保证。

有没有写一个类似的$表的方式？

  $ $范围watchGroup（['数字1'，'编号2'，'myArray的']，回调，真正的）。 //如此objectEquality
 

解决方案

嘛，好像watchGroup不支持深手表。所以，很可能你可以做一个黑客，通过与来自手表的功能传递价值观的阵列注册匿名深刻的观察家。

  $范围。$表（函数（）{
     返回['数字1'，'编号2'，'myArray的']图。（angular.bind（$范围，$范围$ EVAL））;
  }，功能（newV）{
      的console.log（newV）;
  }，真正）;
 

或只是从任何继承范围添加此功能的rootScope效用函数和访问它。

  .RUN（函数（$ rootScope）{
  $ rootScope.deepWatchGroup =功能（EXP，回调）{
    如果收益率（angular.isArray（EXP）|| $ thisScope手表！）; //或者记录一些错误，如果阵列不是传入或上下文是不是一个真正的范围对象   VAR thisScope =这个，//获取范围
        evalFunc = angular.bind（thisScope，thisScope $ EVAL）; //一个必然的eval FUNC     thisScope。$表（函数（）{
        返回exp.map（evalFunc）; //返回评估值数组
     }回调，真正的）;
   }
}）;
 

和从你的控制器做的：

  $ scope.deepWatchGroup（['数字1'，'编号2'，'myArray的']，功能（newV）{
  的console.log（newV）;
}）;
 

I want a directive to re-render HTML whenever three scope variables have changed. The first two are just integers, the third is an array.

We have $watchGroup to watch several variables, we have $watch with objectEquality as a third parameter, and we have $watchCollection which is like $watch, but with objectEquality implied.

Is there a way to write a $watch similar to this?

$scope.$watchGroup(['number1', 'number2', 'myArray'], callback, true); // true for objectEquality

解决方案

Well it seems like watchGroup does not support a deep watch. So probably you can do a hack, by registering an anonymous deep watcher with array of values being passed in from the watch function.

$scope.$watch(function(){
     return ['number1','number2','myArray'].map(angular.bind($scope, $scope.$eval));
  }, function(newV){
      console.log(newV);
  },true);

Demo

or just add this function as utility function on the rootScope and access it from any inherited scopes.

.run(function($rootScope){
  $rootScope.deepWatchGroup = function(exp, callback){
    if(!angular.isArray(exp) || !thisScope.$watch) return; //Or log some error if array is not passed in or the context is not really a scope object

   var thisScope = this, //get scope
        evalFunc = angular.bind(thisScope, thisScope.$eval); //and a bound eval func

     thisScope.$watch(function(){
        return exp.map(evalFunc); //return array of evaluated values
     }, callback,true);
   }
});

and from your controller do:

$scope.deepWatchGroup(['number1','number2','myArray'],function(newV){
  console.log(newV);
});

Demo

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