Angular 7 - 重新加载/刷新数据不同的组件

Question

如何在组件 2 发生更改时刷新不同组件 1 中的数据。这两个组件不在同一父节点下。

customer.service.ts

export class UserManagementService extends RestService {

  private BASE_URL_UM: string = '/portal/admin';

  private headers = new HttpHeaders({
    'Authorization': localStorage.getItem('token'),
    'Content-Type': 'application/json'
  });

  constructor(protected injector: Injector,
    protected httpClient: HttpClient) {
    super(injector);
  }
  getEapGroupList(): Observable < EapGroupInterface > {
    return this.get < GroupInterface >
      (this.getFullUrl(`${this.BASE_URL_UM}/groups`), {
        headers: this.headers
      });
  }

  updateGroup(body: CreateGroupPayload): Observable < CreateGroupPayload > {
    return this.put < GroupPayload >
      (this.getFullUrl(`${this.BASE_URL_UM}/group`), body, {
        headers: this.headers
      });
  }
}

Component1.ts

export class UserGroupComponent implements OnInit {

  constructor(private userManagementService: UserManagementService) {}

  ngOnInit() {
    this.loadGroup();
  }

  loadGroup() {
    this.userManagementService.getEapGroupList()
      .subscribe(response => {
        this.groups = response;
      })
  }

}

<mat-list-item *ngFor="let group of groups?.groupList" role="listitem">
  <div matLine [routerLink]="['/portal/user-management/group', group.groupCode, 'overview']" [routerLinkActive]="['is-active']">
    {{group.groupName}}
  </div>
</mat-list-item>
<mat-sidenav-content>
  <router-outlet></router-outlet>
</mat-sidenav-content>

component2.ts

setPayload() {
  const formValue = this.newGroupForm.value
  return {
    'id': '5c47b24918a17c0001aa7df4',
    'groupName': formValue.groupName,
  }
}

onUpdateGroup() {
    this.userManagementService.updateGroup(this.setPayload())
      .subscribe(() => {
          console.log('success);
          })
      }

当我在 component1 中更新 onUpdateGroup() api 时，loadGroup() 应该在 component2 中刷新

Answer 1

将检索数据的代码移至服务，以便服务维护组。

然后将组件 1 中的数据包装在一个 getter 中:

get groups() {
  return this.userManagementService.groups
}

然后每次数据发生变化时，Angular 的依赖注入(inject)会自动调用 getter 并获取最新的值。

修改后的服务

export class UserManagementService extends RestService {
  groups;
  private BASE_URL_UM: string = '/portal/admin';

  private headers = new HttpHeaders({
    'Authorization': localStorage.getItem('token'),
    'Content-Type': 'application/json'
  });

  constructor(protected injector: Injector,
    protected httpClient: HttpClient) {
    super(injector);

    // Get the data here in the service
    this.loadGroup();
  }

  getEapGroupList(): Observable < EapGroupInterface > {
    return this.get < GroupInterface >
      (this.getFullUrl(`${this.BASE_URL_UM}/groups`), {
        headers: this.headers
      });
  }

  loadGroup() {
    this.getEapGroupList()
      .subscribe(response => {
        this.groups = response;
      })
  }

  updateGroup(body: CreateGroupPayload): Observable < CreateGroupPayload > {
    return this.put < GroupPayload >
      (this.getFullUrl(`${this.BASE_URL_UM}/group`), body, {
        headers: this.headers
      }).pipe(
         // Reget the data after the update
         tap(() => this.loadGroup()
      );
  }
}

修订后的组件 1

export class UserGroupComponent implements OnInit {
    get groups() {
      return this.userManagementService.groups
    }

  constructor(private userManagementService: UserManagementService) {}

  ngOnInit() {

  }
}

注意:此代码未经过语法检查!

我这里有一个类似的工作示例:https://github.com/DeborahK/Angular-Communication/tree/master/APM-FinalWithGetters

(检查 product-shell 文件夹文件和 product.service.ts)