用AngularJS深度合并对象

Z时代
2024-01-10
分类：问答

通常我会使用浅拷贝对象 angular.extend()

这是一个例子：

var object1 = {
  "key": "abc123def456",
  "message": {
    "subject": "Has a Question",
    "from": "example1@example.com",
    "to": "example2@example.com"
   }
};
var object2 = {
  "key": "00700916391"
};
console.log(angular.extend({}, object1, object2));

将给我们：

{
 "key": "00700916391",
 "message": {
   "subject": "Has a Question",
   "from": "example1@example.com",
   "to": "example2@example.com"
  }
}

但是，如果我想合并对象以使父键不会被子对象覆盖，该怎么办：

var object1 = {
  "key": "abc123def456",
  "message": {
    "subject": "Has a Question",
    "from": "example1@example.com",
    "to": "example2@example.com"
   }
};
var object2 = {
  "key": "00700916391",              //Overwrite me
  "message": {                       //Dont overwrite me!
    "subject": "Hey what's up?",     //Overwrite me
    "something": "something new"     //Add me
   }
};
console.log(merge(object1, object2));

将给我们：

{ "key": "00700916391", "message": { "subject": "Hey what's up?", "from": "example1@example.com", "to": "example2@example.com", "something": "something new" } }

是否有一个Angular函数已经执行了我不知道的深度合并？

如果不是，则有一种本机方法可以在javascript中递归地执行n个级别的操作。

回答：

用途angular.merge：

不同于extend()，merge()递归地进入源对象的对象属性，执行深层复制。

angular.merge(object1, object2); // merge object 2 into object 1

没有理由不应该使用简单的递归算法：)

假设它们都是JSON.stringify或类似结果：

function merge(obj1,obj2){ // Our merge function
    var result = {}; // return result
    for(var i in obj1){      // for every property in obj1 
        if((i in obj2) && (typeof obj1[i] === "object") && (i !== null)){
            result[i] = merge(obj1[i],obj2[i]); // if it's an object, merge   
        }else{
           result[i] = obj1[i]; // add it to result
        }
    }
    for(i in obj2){ // add the remaining properties from object 2
        if(i in result){ //conflict
            continue;
        }
        result[i] = obj2[i];
    }
    return result;
}