Question

在我的角度应用程序中，我得到的响应如下。

[{
    "proposalId": "cc0bcd90-fc75-4c73-bd66-799b37330fb5",
    "proposalGpId": "cc0bcd90-fc75-4c73-bd66-799b37380fb5",
    "eventId": "17e69ea1-54da-11e7-9469-985aebe2005e",
    "listingId": "pdf19f7e1-5f2b-4d02-a48d-3b6d0189b5d1",
    "status": "Approved"
}, {
    "proposalId": "cc0bcd90-fc75-4c73-bd66-799b373306b5",
    "proposalGpId": "cc0bcd90-fc75-4c73-bd66-799b37380fb5",
    "eventId": "17e69ea1-54da-11e7-9469-985aebe2005e",
    "listingId": "pdf19f7e1-5f2b-4d02-a48d-3b6d0189b5d1",
    "status": "Approved"
}]

我在应用程序上有两个类，

ProposalGroup.ts

export class ProposalGroup {
    eventId: string;
    proposalGpId: string;
    proposals: Proposal[];
}

Proposal.ts

export class Proposal {
    proposalId: string;
    listingId: Date;
    eventId: Price;
    status: string;
}

我需要从上面的JSON中创建一个ProposalGroups数组，什么时候提案具有相同的listingId它应该被分组。

我想生成 output ，如下所示，

[{
    "eventId": "17e69ea1-54da-11e7-9469-985aebe2005e",
    "proposals": [{
        "proposalId": "cc0bcd90-fc75-4c73-bd66-799b37330fb5",
        "proposalGpId": "cc0bcd90-fc75-4c73-bd66-799b37380fb5",
        "eventId": "17e69ea1-54da-11e7-9469-985aebe2005e",
        "listingId": "pdf19f7e1-5f2b-4d02-a48d-3b6d0189b5d1",
        "status": "approved"
    }, {
        "proposalId": "cc0bcd90-fc75-4c73-bd66-799b373306b5",
        "proposalGpId": "cc0bcd90-fc75-4c73-bd66-799b37380fb5",
        "eventId": "17e69ea1-54da-11e7-9469-985aebe2005e",
        "listingId": "pdf19f7e1-5f2b-4d02-a48d-3b6d0189b5d1",
        "status": "approved"
    }]
}]

这是我尝试使用lodash，

const grouped = _.groupBy(this.proposals, (proposal: Proposal) => proposal.listingId);

但上面给出了一本字典。

Answer 1

var proposals = [{
    "proposalId": "cc0bcd90-fc75-4c73-bd66-799b37330fb5",
    "proposalGpId": "cc0bcd90-fc75-4c73-bd66-799b37380fb5",
    "eventId": "17e69ea1-54da-11e7-9469-985aebe2005e",
    "listingId": "pdf19f7e1-5f2b-4d02-a48d-3b6d0189b5d1",
    "status": "Approved"
}, {
    "proposalId": "cc0bcd90-fc75-4c73-bd66-799b373306b5",
    "proposalGpId": "cc0bcd90-fc75-4c73-bd66-799b37380fb5",
    "eventId": "17e69ea1-54da-11e7-9469-985aebe2005e",
    "listingId": "pdf19f7e1-5f2b-4d02-a48d-3b6d0189b5d1",
    "status": "Approved"
}];

console.log('proposals : ', _.chain(/*this.*/proposals)

    .groupBy("listingId")
    .transform((result, value, key)=>{
        result.push({"listingId": key, proposals: value});
    }, [])
    .value()
);

.as-console-wrapper { max-height: 100%!important; top: 0; }

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

这会将字典转换为对象数组。

Answer 2

将组分组，然后将组映射到新数组：

const proposals = [{"proposalId":"cc0bcd90-fc75-4c73-bd66-799b37330fb5","proposalGpId":"cc0bcd90-fc75-4c73-bd66-799b37380fb5","eventId":"17e69ea1-54da-11e7-9469-985aebe2005e","listingId":"pdf19f7e1-5f2b-4d02-a48d-3b6d0189b5d1","status":"Approved"},{"proposalId":"cc0bcd90-fc75-4c73-bd66-799b373306b5","proposalGpId":"cc0bcd90-fc75-4c73-bd66-799b37380fb5","eventId":"17e69ea1-54da-11e7-9469-985aebe2005e","listingId":"pdf19f7e1-5f2b-4d02-a48d-3b6d0189b5d1","status":"Approved"}];

const result = _(proposals)
  .groupBy('listingId') // group by listingId
  .map((proposals, listingId) => (({
    eventId: proposals[0].eventId, // omit this if you don't want the eventId
    listingId, // omit it if you don't want the listingId
    proposals
  })))
  .value();
  
console.log(result);

.as-console-wrapper { max-height: 100%!important; top: 0; }

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

按ID分组并从分组数据创建数组

2 个答案: