Angular.copy inside promise with angularjs - angularjs

Question

I need to make a copy of an object, but this object is inside a promise.
When I modify the object a, the object b is modified too.
I know that it can be due to async mode with promise, but I can not figure out it.
Simplifying my code, I have something like this:
The promise:
$scope.search = function () {
DocumentFactory.getDocuments(dataParams).then(function (data) {
makeFacets(data);
},
function (data) {
$scope.errorMessages.search = true;
});
};
It will search into many topics and will return some of them.
Then I create an array with that topics:
var makeFacets = function(data) {
$scope.topics=[];
$scope.topics[0] ={father: "General", label:""};
$scope.topics[1] ={father: "International", label:""};
$scope.topics[2] ={father: "Crime", label:""};
$scope.topics[3] ={father: "NonLegal", label:""};
[...]
};
Once I have the object, I use it to show that topics and also to filter inside that topics:
<div class="filter-box">
<input type="input" class="form-control" ng-model="filter.topic" ng-change="test1()">
</div>
<div class="filter-name" ng-repeat="data in topics">
<span>{{data.label}}</span>
</div>
My last step is try to filter inside that topics, to do that, I need to make a copy of the topics.
$scope.allTopics = [];
$scope.test1 = function(){
if($scope.allTopics.length === 0){
angular.copy($scope.topics, $scope.allTopics);
}
$scope.topics = $scope.allTopics;
var filter = $scope.filter.topic;
if(filter.length>=3){
for(var i = 0; i<$scope.topics.length; i++){
if($scope.topics[i].children !== undefined){
for(var j = 0; j<$scope.topics[i].children.length; j++){
if($scope.topics[i].children[j].label.toLowerCase().indexOf(filter.toLowerCase()) === -1){
$scope.topics[i].children.splice(j, 1);
}
}
}
}
}
};
This is not working, of course. I have tried a lot of things more but no one is working.
Also I have tried to add the copy here:
$scope.search = function () {
DocumentFactory.getDocuments(dataParams).then(function (data) {
makeFacets(data);
$scope.allTopics = [];
angular.copy($scope.topics, $scope.allTopics);
},
function (data) {
$scope.errorMessages.search = true;
});
};
All time I modify the topics object, the all Topics object is also modified.

Answer 1

The issue is that you are doing an assignment after calling copy. Thus, the two variables reference the same object leading to the problem you observe. Just leave out the assignment after you have copied it or do a copy instead of an assignment.
if($scope.allTopics.length === 0){
angular.copy($scope.topics, $scope.allTopics);
}
$scope.topics = $scope.allTopics; // <-- this assignment is wrong
Note you can also use copy in a more assignment-like fashion:
$scope.topics = angular.copy($scope.allTopics);