根据JavaScript中的条件合并两个嵌套的JSON对象

Question

I'm trying to figure out how to merge two JSON objects and create a merged object based on conditionals.

I want to loop through leadlistArray, get the rules.id for each entry and match it against rulesArray. The final outcome should be the finalArray.

leadlistArray = {
 "status": "success",
 "data": {
  "leadlists": [
   {
    "rules": [
     {
      "$oid": "53866d4d1fd21c3cc41f52da"
     }
    ],
    "name": "List 1: only general rule"
   },
   {
    "rules": [
     {
      "$oid": "53866d4d1fd21c3cc41f52da"
     },
     {
      "$oid": "53866d9c1fd21c3cc79bf7ce"
     },
     {
      "$oid": "53866d9c1fd21c3cc79bf2cd"
     }
    ],
    "name": "List 2: general and web-based rule"
   },
   {
    "rules": [
     {
      "$oid": "53866d9c1fd21c3cc79bf7ce"
     }
    ],
    "name": "List 3: only web-based rule"
   }
  ]
 }
}

Rules array:

rulesArray = {
 "status": "success",
 "data": {
  "rules": [
   {
    "description": "optimizely no!",
    "start_time": "",
    "values": [
     "optimizely"
    ],
    "end_time": "",
    "operator": "",
    "_id": {
     "$oid": "53866d4d1fd21c3cc41f52da"
    },
    "type": 0,
    "condition": 1
   },
   {
    "description": "google_plus no!",
    "start_time": "",
    "values": [
     "google_plus"
    ],
    "end_time": "",
    "operator": "",
    "_id": {
     "$oid": "53866d9c1fd21c3cc79bf2cd"
    },
    "type": 1,
    "condition": 1
   },
   {
    "description": "google_plus yes!",
    "start_time": "",
    "values": [
     "google_plus"
    ],
    "end_time": "",
    "operator": "",
    "_id": {
     "$oid": "53866d9c1fd21c3cc79bf7ce"
    },
    "type": 1,
    "condition": 0
   }
  ]
 }
}

the finalArray should, for each list, group the rules descriptions by rule type:

finalArray = [
    {'name': 'List 1: only general rule'
    ,'rules':
        {0: [
            {'description': 'optimizely no!'}
        ]}
    },
    {'name': 'List 2: general and web-based rule'
    ,'rules': 
        {0: [
            {'description': 'optimizely no!'}
        ], 1: [
            {'description': 'google_plus yes!'},
            {'description': 'google_plus no!'}
        ]}
    },
    {'name': 'List 3: only web-based rule'
    ,'rules': {
        1: [
            {'description': 'google_plus yes!'}
        ]}
    }
]

Answer 1

Try this http://jsfiddle.net/eN52v/

var rules = rulesArray.data.rules
    .reduce(function(acc, item){
        return acc[item._id.$oid] = {
            description: item.description, 
            type: item.type}, acc; 
    }, {}), //cache rules by id to avoid array lookups.

    finalArray = leadlistArray.data.leadlists.map(function(item) {
        return {
            name: item.name, 
            rules: item.rules.reduce(function(acc, rule){ //Why not an array?
                var ruleDesc = rules[rule.$oid],
                    type = ruleDesc.type;

                (acc[type] || (acc[type] = [])).push({description: ruleDesc.description});
                return acc;}, {})    
        }});