javascript - 使用 AngularJS 深度合并对象

Question

通常对于浅拷贝对象我会使用angular.extend()

举个例子:

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));

会给我们:

{
 "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便父键不被子对象覆盖怎么办:

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));

会给我们:

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

• 是否有 Angular 函数已经进行了我不知道的深度合并？

• 如果没有，是否有一种 native 方法可以在 javascript 中递归执行 n 级深度？

Answer 1

Angular 1.4 或更高版本

使用angular.merge :

Unlike extend(), merge() recursively descends into object properties of source objects, performing a deep copy.

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

---

旧版本的 Angular:

简单的递归算法没有理由不能工作:)

假设它们都是 JSON.stringify 或类似的结果:

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;
}

Here is a working fiddle

(注意，这里不处理数组)