使用lodash中的键值合并一个对象数组？

Question

我正在使用node.js和lodash。

我有这样的数据：

[ 
    { 
    to: [ 'foo@bar.com', 'foo1@bar.com' ], 
    submittedSubs: [ [Object] ] 
    }, 
    { 
    to: [ 'foo@bar.com', 'foo2@bar.com' ], 
    submittedSubs: [ [Object], [Object], [Object] ] 
    } 
] 

我希望把它变成在那里它是由to

[ 
    { 
    to: 'foo@bar.com', 
    submittedSubs: [ [Object],[Object], [Object], [Object] ] 
    }, 
    { 
    to: 'foo1@bar.com', 
    submittedSubs: [ [Object] ] 
    }, 
    { 
    to: 'foo2@bar.com', 
    submittedSubs: [ [Object], [Object], [Object] ] 
    } 
] 

我该怎么做“分类”像这样的数据？

我已经试过这样：

spam[0].to.push('foo@bar.com'); 
spam[0].to.push('foo1@bar.com'); 
spam[1].to.push('foo@bar.com'); 
spam[1].to.push('foo2@bar.com'); 

console.log('data is',spam); 

var byUser=[]; 
_.each(spam, function(data){ 
    _.each(data.to,function(addr){ 
     byUser.push({to:addr,submittedSubs:data.submittedSubs}); 
    }); 
}); 
console.log('attempt',_.merge(byUser)); 

但是，这给了我这样的：

[ { to: 'foo@bar.com', submittedSubs: [ [Object] ] }, 
{ to: 'foo1@bar.com', submittedSubs: [ [Object] ] }, 
{ to: 'foo@bar.com', submittedSubs: [ [Object], [Object], [Object] ] }, 
{ to: 'foo2@bar.com', submittedSubs: [ [Object], [Object], [Object] ] } ] 

Answer 1

这会为你工作：

var unique = {}; 
byUser.forEach(function(user) { 
    unique[user.to] = unique[user.to] || []; 
    unique[user.to] = unique[user.to].concat(user.submittedSubs); 
}); 
unique = Object.keys(unique).map(function (key, i) { 
    return {to: key, submittedSubs: unique[key]}; 
}); 

/* 
[ { to: 'foo@bar.com', submittedSubs: [ [Object] ] }, 
{ to: 'foo1@bar.com', submittedSubs: [ [Object] ] }, 
{ to: 'foo2@bar.com', submittedSubs: [ [Object], [Object], [Object], [Object] ] } ] 
*/ 

---

我站在因此这应该可以通过电话来实现_.uniq的后退功能，但我无法按照您需要的方式工作。

你应该能够最终阵列上使用_.uniq从lodash：

_.uniq(byUser, "to"); 

/* 
[ { to: 'foo@bar.com', submittedSubs: [ [Object] ] }, 
{ to: 'foo1@bar.com', submittedSubs: [ [Object] ] }, 
{ to: 'foo2@bar.com', submittedSubs: [ [Object], [Object], [Object] ] } ] 
*/ 

Answer 2

我想有一些不错的lodash设施，以缩短这个了一点，但这里有一个香草JS的解决方案：

var data = [ 
    { 
    to: [ 'foo@bar.com', 'foo1@bar.com' ], 
    submittedSubs: [{ id: 'sub1' }] 
    }, 
    { 
    to: [ 'foo@bar.com', 'foo2@bar.com' ], 
     submittedSubs: [{ id: 'sub2' }, { id: 'sub3' }, { id: 'sub4' }] 
    } 
]; 

var emailSubsMap = data.reduce(function(result, record) { 
    record.to.forEach(function(email) { 
     result[email] = (result[email] || []) 
      .concat(record.submittedSubs); 
    }); 
    return result; 
}, {}); 

var formatted = Object.keys(emailSubsMap).map(function(email) { 
    return { to: email, submittedSubs: emailSubsMap[email] }; 
}).sort(function(a, b) { 
    return a.to <= b.to ? -1 : 1; 
}); 

console.log(JSON.stringify(formatted)); 

（格式化）控制台输出：

[ 
    { 
     "to": "foo1@bar.com", 
     "submittedSubs": [ 
      { "id": "sub1" } 
     ] 
    }, 
    { 
     "to": "foo2@bar.com", 
     "submittedSubs": [ 
      { "id": "sub2" }, 
      { "id": "sub3" }, 
      { "id": "sub4" } 
     ] 
    }, 
    { 
     "to": "foo@bar.com", 
     "submittedSubs": [ 
      { "id": "sub1" }, 
      { "id": "sub2" }, 
      { "id": "sub3" }, 
      { "id": "sub4" } 
     ] 
    } 
] 

请注意，我只是为了测试目的而模拟了submittedSubs对象的外观。

JSFiddle Example

约分拣一对夫妇的注意事项：

• 我的第一个版本不正确排序......它已经更新。 :)
• 您请求的排序方法不遵循JavaScript的“本机”字符串排序顺序。例如，['foo@bar.com', 'foo2@bar.com', 'foo1@bar.com'].sort() --> ['foo1@bar.com','foo2@bar.com','foo@bar.com']，所以如果您真的想要foo@bar.com来到foo1@bar.com之前，您需要更详细地定义排序标准。