Explication détaillée d'exemples de code d'utilisation spécifiques sur la façon de fusionner des objets dans Node.js

Dans Node.js, nous pouvons fusionner deux objets via l'extension du trait de soulignement ou la fusion de lodash, mais comment gérer des objets complexes comme les suivants ?

Node.js fusionne deux objets complexes

Par exemple, il y a les deux objets suivants :

var obj1 = {
 "name" : "myname",
 "status" : 0,
 "profile": { "sex":"m", "isactive" : true},
 "strarr":["one", "three"],
 "objarray": [
 {
  "id": 1,
  "email": "a1@me.com",
  "isactive":true
 },
 {
  "id": 2,
  "email": "a2@me.com",
  "isactive":false
 }
 ]
};

var obj2 = {
 "name" : "myname",
 "status" : 1,
 "newfield": 1,
 "profile": { "isactive" : false, "city": "new York"},
 "strarr":["two"],
 "objarray": [
 {
  "id": 1,
  "isactive":false
 },
 {
  "id": 2,
  "email": "a2modified@me.com"
 },
 {
  "id": 3,
  "email": "a3new@me.com",
  "isactive" : true
 }
 ]
};

J'espère que le résultat fusionné sera le suivant :

{ name: 'myname',
 status: 1,
 profile: { sex: 'm', isactive: false, city: 'new York' },
 strarr: [ 'one', 'three', 'two' ],
 objarray: 
 [ { id: 1, email: 'a1@me.com', isactive: false },
 { id: 2, email: 'a2modified@me.com', isactive: false },
 { id: 3, email: 'a3new@me.com', isactive: true } ],
newfield: 1 }

Nous ne pouvons pas obtenir le résultat ci-dessus grâce aux méthodes existantes de soulignez ou lodash, alors vous ne pouvez écrire du code que vous-même pour y parvenir.

function mergeObjs(def, obj) {
 if (!obj) {
 return def;
 } else if (!def) {
 return obj;
 }

 for (var i in obj) {
 // if its an object
 if (obj[i] != null && obj[i].constructor == Object)
 {
  def[i] = mergeObjs(def[i], obj[i]);
 }
 // if its an array, simple values need to be joined. Object values need to be remerged.
 else if(obj[i] != null && (obj[i] instanceof Array) && obj[i].length > 0)
 {
  // test to see if the first element is an object or not so we know the type of array we're dealing with.
  if(obj[i][0].constructor == Object)
  {
  var newobjs = [];
  // create an index of all the existing object IDs for quick access. There is no way to know how many items will be in the arrays.
  var objids = {}
  for(var x= 0, l= def[i].length ; x < l; x++ )
  {
   objids[def[i][x].id] = x;
  }

  // now walk through the objects in the new array
  // if the ID exists, then merge the objects.
  // if the ID does not exist, push to the end of the def array
  for(var x= 0, l= obj[i].length; x < l; x++)
  {
   var newobj = obj[i][x];
   if(objids[newobj.id] !== undefined)
   {
   def[i][x] = mergeObjs(def[i][x],newobj);
   }
   else {
   newobjs.push(newobj);
   }
  }

  for(var x= 0, l = newobjs.length; x<l; x++) {
   def[i].push(newobjs[x]);
  }
  }
  else {
  for(var x=0; x < obj[i].length; x++)
  {
   var idxObj = obj[i][x];
   if(def[i].indexOf(idxObj) === -1) {
    def[i].push(idxObj);
   }
  }
  }
 }
 else
 {
  def[i] = obj[i];
 }
 }
 return def;}

En améliorant légèrement le code ci-dessus, nous pouvons ajouter automatiquement des valeurs de type Number pendant le processus de fusion.

function merge(def, obj) {
 if (!obj) {
  return def;
 }
 else if (!def) {
  return obj;
 }

 for (var i in obj) {
  // if its an object
  if (obj[i] != null && obj[i].constructor == Object)
  {
   def[i] = merge(def[i], obj[i]);
  }
  // if its an array, simple values need to be joined. Object values need to be re-merged.
  else if(obj[i] != null && (obj[i] instanceof Array) && obj[i].length > 0)
  {
   // test to see if the first element is an object or not so we know the type of array we're dealing with.
   if(obj[i][0].constructor == Object)
   {
    var newobjs = [];
    // create an index of all the existing object IDs for quick access. There is no way to know how many items will be in the arrays.
    var objids = {}
    for(var x= 0, l= def[i].length ; x < l; x++ )
    {
     objids[def[i][x].id] = x;
    }

    // now walk through the objects in the new array
    // if the ID exists, then merge the objects.
    // if the ID does not exist, push to the end of the def array
    for(var x= 0, l= obj[i].length; x < l; x++)
    {
     var newobj = obj[i][x];
     if(objids[newobj.id] !== undefined)
     {
      def[i][x] = merge(def[i][x],newobj);
     }
     else {
      newobjs.push(newobj);
     }
    }

    for(var x= 0, l = newobjs.length; x<l; x++) {
     def[i].push(newobjs[x]);
    }
   }
   else {
    for(var x=0; x < obj[i].length; x++)
    {
     var idxObj = obj[i][x];
     if(def[i].indexOf(idxObj) === -1) {
      def[i].push(idxObj);
     }
    }
   }
  }
  else
  {
   if (isNaN(obj[i]) || i.indexOf(&#39;_key&#39;) > -1){
    def[i] = obj[i];
   }
   else{
    def[i] += obj[i];
   }
  }
 }
 return def;
}

Par exemple, il y a les deux objets suivants :

var data1 = {
 "_id" : "577327c544bd90be508b46cc",
 "channelId_info" : [
 {
  "channelId_key" : "0",
  "secondLevel_group" : [
  {
   "secondLevel_key" : "568cc36c44bd90625a045c60",
   "sender_group" : [
   {
    "sender_key" : "577327c544bd90be508b46cd",
    "sender_sum" : 40.0
   }
   ],
   "senders_sum" : 40.0
  }
  ],
  "channelId_sum" : 40.0
 }
 ],
 "car_sum" : 40.0
};

var data2 = {
 "_id" : "577327c544bd90be508b46cc",
 "channelId_info" : [
 {
  "channelId_key" : "0",
  "secondLevel_group" : [
  {
   "secondLevel_key" : "568cc36c44bd90625a045c60",
   "sender_group" : [
   {
    "sender_key" : "577327c544bd90be508b46cd",
    "sender_sum" : 20.0
   },
   {
    "sender_key" : "5710bcc7e66620fd4bc0914f",
    "sender_sum" : 5.0
   }
   ],
   "senders_sum" : 25.0
  },
  {
   "secondLevel_key" : "55fbeb4744bd9090708b4567",
   "sender_group" : [
   {
    "sender_key" : "5670f993a2f5dbf12e73b763",
    "sender_sum" : 10.0
   }
   ],
   "senders_sum" : 10.0
  }
  ],
  "channelId_sum" : 35.0
 },
 {
  "channelId_key" : "1",
  "secondLevel_group" : [
  {
   "secondLevel_key" : "568cc36c44bd90625a045c60",
   "sender_group" : [
   {
    "sender_key" : "577327c544bd90be508b46cd",
    "sender_sum" : 20.0
   }
   ],
   "senders_sum" : 20.0
  }
  ],
  "channelId_sum" : 20.0
 }
 ],
 "car_sum" : 55.0
};

Le résultat après fusion est la suivante :

{
 "_id": "577327c544bd90be508b46cc",
 "channelId_info": [
  {
   "channelId_key": "0",
   "secondLevel_group": [
    {
     "secondLevel_key": "568cc36c44bd90625a045c60",
     "sender_group": [
      {
       "sender_key": "577327c544bd90be508b46cd",
       "sender_sum": 60
      },
      {
       "sender_key": "5710bcc7e66620fd4bc0914f",
       "sender_sum": 5
      }
     ],
     "senders_sum": 65
    },
    {
     "secondLevel_key": "55fbeb4744bd9090708b4567",
     "sender_group": [
      {
       "sender_key": "5670f993a2f5dbf12e73b763",
       "sender_sum": 10
      }
     ],
     "senders_sum": 10
    }
   ],
   "channelId_sum": 75
  },
  {
   "channelId_key": "1",
   "secondLevel_group": [
    {
     "secondLevel_key": "568cc36c44bd90625a045c60",
     "sender_group": [
      {
       "sender_key": "577327c544bd90be508b46cd",
       "sender_sum": 20
      }
     ],
     "senders_sum": 20
    }
   ],
   "channelId_sum": 20
  }
 ],
 "car_sum": 95
}

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