如何将可观察对象与角度数组匹配

Question

Here's the code:

//this is the code that I tried it return undefined
this.server$.subscribe(param => {
      console.log(param);
      const sample = param.find(x => x === data.server);
      console.log(sample);
    });

return this.fb.group({
  server: [data && data['server'] || '', [Validators.required, Validators.email]],
});

The data of this.server$ observable:

[{
code: "S1"
createdBy: "admin"
id: "1cUMlNRSamZHD"
name: "Server1"
status: "ACTIVE"
timeCreated: "2019-09-13 17:02:33"
timeUpdated: "2019-09-19 14:38:41"
},{
code: "S2"
createdBy: "admin"
id: "w1lPuzJ8iJQp"
name: "Server2"
status: "ACTIVE"
timeCreated: "2019-08-30 15:24:44"
timeUpdated: "2019-12-10 16:54:17"
},{
code: "S3"
createdBy: "admin"
id: "HIEkQKjpM54V"
name: "Server3"
status: "ACTIVE"
timeCreated: "2019-08-05 11:00:59"
timeUpdated: "2019-08-05 11:00:59"
},{
code: "S4"
createdBy: "admin"
id: "1foD7MVZRwYzr"
name: "Server4"
status: "ACTIVE"
timeCreated: "2019-08-30 21:06:23"
timeUpdated: "2019-12-10 16:54:22"
}]

For example It click the data to update. Then the value of data.server

    server :[{
    id: 1foD7MVZRwYzr,
    code: S4,
    name: Server4
    },{
    id: HIEkQKjpM54V,
    code: S3,
    name: Server3
    }]

What I want here is.

When it click the item where it has two server or 1.

It should find it in the observable.

And it will display in the nz-select multiple

<nz-select formControlName="server" name="server" nzPlaceHolder="Select server(s)" [nzMode]="'multiple'" nzAllowClear>
              <nz-option *ngFor="let server of (server$ | async)" [nzLabel]="server.name" [nzValue]="server"></nz-option>
            </nz-select>

It should display on the nz-select Server4 and Server3

const server = this.server$.value.filter(param => data.server.find(x => x.id === param.id));

I tried this it work, but it doesn't display on the nz-select

Answer 1

You need to declare a variable which stores a response:

TypeScript:

fooData;

this.server$.subscribe(param => {
  console.log(param);
  this.fooData = param.find(x => x === data.server);
  console.log(this.fooData);
});

HTML:

<nz-select 
    formControlName="server" name="server" 
    nzPlaceHolder="Select server(s)" [nzMode]="'multiple'" nzAllowClear>
    <nz-option 
        *ngFor="let server of fooData" 
        [nzLabel]="server.name" [nzValue]="server">
    </nz-option>
</nz-select>

Or if you want to use async pipe, then you do need to call subscribe method as async pipe does it:

server$

ngOnInit() {
    this.server$ = this.someApMethod.getAll();
}

HTML:

<nz-select formControlName="server" name="server" 
    nzPlaceHolder="Select server(s)" [nzMode]="'multiple'" nzAllowClear>
    <nz-option *ngFor="let server of (server$ | async)" [nzLabel]="server.name" 
        [nzValue]="server">
    </nz-option>
</nz-select>