RxJs groupBy 带有一个对象数组,每个对象都有键和值数组 [英] RxJs groupBy with an array of objects each having key and values array
问题描述
所以要求是这样的:我得到了一个对象数组(例如数组)
<预><代码>[{ empDept:'工程',empLoc:'浦那',empName:'约翰'},{ empDept:'工程',empLoc:'孟买',empName:'哈利'},{ empDept:'人力资源',empLoc:'浦那',empName:'丹尼斯'},{ empDept: '金融', empLoc: '孟买', empName: '猫王' },]我将有一个函数,该函数将接受属性名称作为参数,员工列表将根据该名称进行分组.所以如果输入参数值为'empDept',那么我想要的结果如下:
<预><代码>[{键:'工程',值: [{ empDept:'工程',empLoc:'浦那',empName:'约翰'},{ empDept:'工程',empLoc:'孟买',empName:'哈利'},]},{键:'人力资源',值: [{ empDept:'人力资源',empLoc:'浦那',empName:'丹尼斯'},]},{关键:'财务',值: [{ empDept: '金融', empLoc: '孟买', empName: '猫王' },]}]我正在使用 RxJs groupBy 操作符来实现这一点.我已经尝试了下面的代码,但它似乎没有给出想要的结果:
this.groupedEmployees$ =雇员$.pipe(groupBy(person => person.empDept),mergeMap(group => of({ key: group.key, values: group.pipe(mergeMap(x => toArray())) })),);
感谢您的帮助.
如果你真的想坚持使用 RxJS,你可以使用这段代码:
import { from } from 'rxjs';import { groupBy, mergeMap, reduce, toArray } from 'rxjs/operators';const groupedEmployees$ = from([{ empDept:'工程',empLoc:'浦那',empName:'约翰'},{ empDept:'工程',empLoc:'孟买',empName:'哈利'},{ empDept:'人力资源',empLoc:'浦那',empName:'丹尼斯'},{ empDept:'金融',empLoc:'孟买',empName:'猫王'}]).管道(groupBy(person => person.empDept),合并映射(组 => 组.管道(减少((acc,cur)=> {acc.values.push(cur);返回acc;},{ 键:group.key,值:[]}))),toArray());groupedEmployees$.subscribe(console.log);
So the requirement is like: I got a array of objects (e.g. Array)
[
{ empDept: 'Engineering', empLoc: 'Pune', empName: 'John' },
{ empDept: 'Engineering', empLoc: 'Mumbai', empName: 'Harry' },
{ empDept: 'HR', empLoc: 'Pune', empName: 'Denis' },
{ empDept: 'Finance', empLoc: 'Mumbai', empName: 'Elvis' },
]
I will have a function which will accept the name of the property as a parameter, on which the employee list will be grouped. So if the input parameter value is 'empDept', then I want the result as below:
[
{
key: 'Engineering',
values: [
{ empDept: 'Engineering', empLoc: 'Pune', empName: 'John' },
{ empDept: 'Engineering', empLoc: 'Mumbai', empName: 'Harry' },
]
},
{
key: 'HR',
values: [
{ empDept: 'HR', empLoc: 'Pune', empName: 'Denis' },
]
},
{
key: 'Finance',
values: [
{ empDept: 'Finance', empLoc: 'Mumbai', empName: 'Elvis' },
]
}
]
I'm using the RxJs groupBy operator to achieve this. I have tried the below code, but it doesn't seem to give the desired result:
this.groupedEmployees$ = employees$.pipe(
groupBy(person => person.empDept),
mergeMap(group => of({ key: group.key, values: group.pipe(mergeMap(x => toArray())) })),
);
Appreciate your help.
If you really want to stick with RxJS, you can use this piece of code:
import { from } from 'rxjs';
import { groupBy, mergeMap, reduce, toArray } from 'rxjs/operators';
const groupedEmployees$ = from([
{ empDept: 'Engineering', empLoc: 'Pune', empName: 'John' },
{ empDept: 'Engineering', empLoc: 'Mumbai', empName: 'Harry' },
{ empDept: 'HR', empLoc: 'Pune', empName: 'Denis' },
{ empDept: 'Finance', empLoc: 'Mumbai', empName: 'Elvis' }
]).pipe(
groupBy(person => person.empDept),
mergeMap(group => group
.pipe(
reduce((acc, cur) => {
acc.values.push(cur);
return acc;
},
{ key: group.key, values: [] }
)
)
),
toArray()
);
groupedEmployees$.subscribe(console.log);
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