javascript - angularjs $watch 无法检测对象中属性的更改

Question

我正在为 $scope 对象设置监视，除非整个值发生更改，否则不会触发 $watch 更改事件

示例:

//Some where in .run function i set rootScope and set $watch too.
$rootScope.config = {date:'11/4/2015',moreValues:'etc'};

//setting $watch
$rootScope.$watch('config',function(new,old) {
console.log('config value changed :)',new);
});

//----->Inside Controller----------

//NOw THIS WILL NOT TRIGGER $watch
$rootScope.config.date = 'another day';

//Same as this, it will also not trigger $watch
var temp = $rootScope.config;
temp.date = 'another day';
$rootScope.config = temp;

//YET THIS WILL WORK JUST FINE :) AND WILL TRIGGER $watch
var temp = angular.copy($rootScope.config);
temp.date = 'another day';
$rootScope.config = temp;

有人可以告诉我为什么会出现这种行为吗？有没有更好的方法在对象属性更改时触发 $watch ？

Answer 1

您可以使用 $watchCollection，或将第三个参数传递为 true

$rootScope.$watch('config',function(value,old) {
console.log('config value changed :)',value);
}, true);

或

$rootScope.$watchCollection('config',function(value,old) {
console.log('config value changed :)',value);
});

• Scope $watch() vs. $watchCollection() In AngularJS