角度6管道RxJs运算符可链接3个相关的可观测对象

问题描述

我有3个依赖的Rest API资源(可以说是可观察的)，如下所示:

I have 3 dependent Rest API resources (lets say observables) like this:

第一个可观察对象将一项作为用户数组生成，如下所示:

1st observable produces one item as array of users, like this:

getUsers(): Observable<User[]>
    [
      {
        "id": 1,
        "name": "Peter",
        "surname": "Smith"
      },
      {
        "id": 2,
        "name": "John",
        "surname": "Wayne"
      },
      ...
    ]

第二个可观察对象可用于获取分配给用户的地址，因此输入参数为用户ID，并以地址数组的形式返回一项:

2nd observable can be used to fetch addresses assigned to user, so the input parameter is User ID, and returns a one item as array of addresses:

getUserAddresses(user_id: string): Observable<Address[]>
    [
      {
        "id": 1,
        "city": "London",
        "street": "Wicombe 34"
      },
      {
        "id": 2,
        "city": "Paris",
        "street": "La fever 20"
      },
      ...
    ]

第三观察者可用于获取分配给用户的公司，因此输入参数为用户ID，并以公司数组的形式返回一个项目:

3rd observable can be used to fetch companies assigned to user, so the input parameter is User ID, and returns a one item as array of companies:

getUserCompanies(user_id: string): Observable<Company[]>
    [
      {
        "id": 1,
        "name": "Fintch CO",
        "state": "France"
      },
      {
        "id": 2,
        "name": "C&C inc.",
        "state": "USA"
      },
      ...
    ]

---

我想将这三个可观察值链接到一个，将其作为一项再次产生结果，其中将包含用户数组及其附加地址数组和公司数组，如下所示:

---

I want to chain these 3 observables into one which will produce the result again as one item, that will contain array of users with their additional addresses arrays and companies array, like following:

    [
      {
        "id": 1,
        "name": "Peter",
        "surname": "Smith",
        "addreesses":
               [
                 {
                   "id": "1",
                   "city": "London",
                   "street": "Wicombe 34"
                 },
                 {
                   "id": "2",
                   "city": "",
                   "street": "La fever 20"
                 }
               ],
        "companies":
               [
                 {
                   "id": "1",
                   "name": "Fintch CO",
                   "state": "France"
                 },
                 {
                   "id": "2",
                   "name": "C&C inc.",
                   "state": "USA"
                 }
               ]
        }
      },
      {
        "id": 2,
        "name": "John",
        "surname": "Wayne",
        "addresses": [...],
        "companies": [...],
      },
      ...
    ]

使用RxJ 6在Angular 6中如何实现类似的运算符组合?非常感谢您的建议.

How should look like the operators composite to achieve that in Angular 6 with RxJs 6?Thanks a lot for advice.

推荐答案

类似的方法可能有效

getUsers()
.pipe(
  switchMap(users => from(users)),
  mergeMap(user => forkJoin(getAddresses(user.id), getCompanies(user.id))
                   .pipe(map(data => ({user, addresses: data[0], companies: data[1] })))
  tap(data => data.user.addresses = data.addresses),
  tap(data => data.user.companies = data.companies),
  map(data => data.user),
  toArray()
  )
)

此处.

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