按ID分组并根据分组的数据创建一个数组

Question

在我的有角度的应用程序中，我得到如下响应。

[{
    "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[];
}

提案

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

我需要根据上述JSON创建一个ProposalGroups数组，当投标具有相同的listingId时，应将其分组。

我想生成如下output ，

[{
    "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"
    }]
}]

这就是我尝试使用lodash的方式，

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

但是上面给出了一个字典。

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

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>