AngularJs $ watchGroup - 这当然pression组中的最后更改？

问题描述

使用 $ watchGroup ，我怎么能确定前pression组中被更改

  $范围。$ watchGroup（['减速'，'本'，'月'，'十六进制']，功能（newValues​​，oldValues​​，范围）{
       last_changed =？ //返回该记录在此运行改变了... ...
       如果（last_changed =='减速'）//那么什么
       如果（last_changed =='本'）//那么什么
       如果（last_changed =='十月'）//那么什么
       如果（last_changed =='十六进制'）//那么什么
    }）;
 

结果
编辑1： -
结果--->问题是我无法从newValues​​取消绑定n_vals。

  VAR n_vals = [];
 $范围。$ watchGroup（['减速'，'本'，'月'，'十六进制']，功能（newValues​​，oldValues​​，范围）{
  LAST_UPDATED = changed_one（newValues​​，n_vals）; // LAST_UPDATED EXP
    n_vals = newValues​​;
 }）;
 

解决方案： -

  n_vals = angular.copy（newValues​​）;
 

看下面的链接：结果
在角

解决方案

角报价 $ watchGroup （自1.3）

基本上它返回的范围变量属性oldValue＆安培;为newValue的方式如何，我们在推它 watchGroup 。

使用范围变量的指数来获得其相应的newval和OLDVAL像下面

有关获得的 newValues​​各自范围变量

newValues​​ [0] 为newValue [1] newValues​​ [2] newValues​​ [3]

有关获得的 oldValues​​各自范围变量

oldValues​​ [0] oldValues​​ [1] oldValues​​ [2] oldValues​​ [3]

  $范围。$ watchGroup（['十二月'，'本'，'十月'，'十六进制']，功能（newValues​​，oldValues​​，范围）{
    的console.log（newValues​​ [指数]）; //把指数值为0（DEC），1（槽），2（OCT）或3（十六进制）
    的console.log（oldValues​​ [指数]）; //把指数值为0（DEC），1（槽），2（OCT）或3（十六进制）
}）;
 

Edit 1

To catch which variable has updated last, You can try below code.

    var arrayOfValues = ['dec', 'bin', 'oct', 'hex'];
    $scope.$watchGroup(arrayOfValues, function(newValues, oldValues, scope) {
        var last_changed;
        if (newValues[0] != oldValues[0]) //or simply consider it as 'dec'
            last_changed = arrayOfValues[0];
        if (newValues[1] != oldValues[1]) //or simply consider it as 'bin'
            last_changed = arrayOfValues[1];
        if (newValues[2] != oldValues[2]) //or simply consider it as 'oct'
            last_changed = arrayOfValues[2];
        if (newValues[3] != oldValues[3]) //or simply consider it as 'hex'
            last_changed = arrayOfValues[3];
        //above logic could simply avoid the below conditional logic(refer comment above in front of if condition)
        if(angular.isDefined(last_changed)){
            //Your logic will come here as per your question
            if(last_changed=='dec') //then something
            if(last_changed=='bin') //then something
            if(last_changed=='oct') //then something
            if(last_changed=='hex') //then something
        }
    });

Edit 2:

I would simply like to minimized the code like below.

var arrayOfValues = ['dec', 'bin', 'oct', 'hex'];
//generic method which will tell you which variable has been updated
$scope.checkWhichVariableHasUpdated = fucntion(watchGroupList, newValuesObj, oldValuesObj) {
    var _lastUpdatedValue;
    angular.forEach(watchGroupList, function(value, index) {
        if (newValuesObj[index] != oldValuesObj[index])
            _lastUpdatedValue = value;
    });
    return _lastUpdatedValue;
};

$scope.mySwitchFunction = function(changedVariable) {
    switch (changedVariable) {
        case 'dec':
            //do something when dec
            break;
        case 'bin':
            //do something when bin
            break;
        case 'oct':
            //do something when oct
            break;
        case 'hex':
            //do something when hex
            break;
    }

};

$scope.$watchGroup(arrayOfValues, function(newValues, oldValues, scope) {
    var last_changed = $scope.checkWhichVariableHasUpdated(arrayOfValues, newValues, oldValues);
    if (angular.isDefined(last_changed)) {
        $scope.mySwitchFunction(last_changed)
    }
});

I believe now you are more cleared on what you want.

Thanks.

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