从外部 API 连接 DataSource

请注意导入所有必需的库。

此示例使用 angular-in-memory-web-api 中的 InMemoryDbService 来提供来自模拟 API 的 JSON 数据。

现场演示

service.ts：

import { Injectable }    from '@angular/core';
import { Headers, Http } from '@angular/http';
import 'rxjs/add/operator/toPromise';

@Injectable()
export class AppState {
  
  private headers = new Headers({'Content-Type': 'application/json'});
  private apiUrl = 'api/data';
  
  constructor(private http: Http) { }
  
  fetchFilterFields() {
    console.log(this.apiUrl);
    return this.http.get(this.apiUrl)
               .toPromise()
               .then(response => response.json().data)
               .catch(this.handleError);
  }
  
  private handleError(error: any): Promise<any> {
    console.error('An error occurred', error); // for demo purposes only
    return Promise.reject(error.message || error);
  }

}

component.ts：

import {Component} from '@angular/core';
import {DataSource} from '@angular/cdk';
import {BehaviorSubject} from 'rxjs/BehaviorSubject';
import {Observable} from 'rxjs/Observable';
import 'rxjs/add/observable/merge';

import { AppState } from './shared.service';

@Component({
  selector: 'md-table-example',
  templateUrl: 'select-form-example.html',
  styleUrls: ['select-form-example.css']
})
export class SelectFormExample implements OnInit {
  
  displayedColumns = ['id', 'name'];
  dataSource: ExampleDataSource | null;
  
  constructor(private appState: AppState){ }
  
  ngOnInit(){
    this.dataSource = new ExampleDataSource(this.appState);
  }
  
}

export interface UserData {
  id: string;
  name: string;
}

export class ExampleDataSource extends DataSource<any> {
  constructor(private appState: AppState) {
    super();
  }
  
  subject: BehaviorSubject<Hero[]> = new BehaviorSubject<Hero[]>([]);

  connect(): Observable<Hero[]> {
      console.log('connect');
      if (!this.subject.isStopped)
          this.appState.fetchFilterFields()
              .then(res => {
                  this.subject.next(res)
              });
      return Observable.merge(this.subject);
  }

  disconnect() {
      this.subject.complete();
      this.subject.observers = [];
  }
}

component.html：

<h2> Material Table </h2>

<div *ngIf="dataSource" class="example-container mat-elevation-z8">
  <md-table #table [dataSource]="dataSource">

    <!-- ID Column -->
    <ng-container cdkColumnDef="id">
      <md-header-cell *cdkHeaderCellDef> ID </md-header-cell>
      <md-cell *cdkCellDef="let row"> {{row.id}} </md-cell>
    </ng-container>

    <!-- Name Column -->
    <ng-container cdkColumnDef="name">
      <md-header-cell *cdkHeaderCellDef> Name </md-header-cell>
      <md-cell *cdkCellDef="let row"> {{row.name}} </md-cell>
    </ng-container>

    <md-header-row *cdkHeaderRowDef="displayedColumns"></md-header-row>
    <md-row *cdkRowDef="let row; columns: displayedColumns;"></md-row>
  </md-table>
</div>

以供参考：

存储器内数据 -service.ts：

import { InMemoryDbService } from 'angular-in-memory-web-api';
export class InMemoryDataService implements InMemoryDbService {
  createDb() {
    const data = [
      { id: 1,  name: 'Ironcast' },
      { id: 2, name: 'Mr. Nice' },
      { id: 3, name: 'Narco' },
      { id: 4, name: 'Bombasto' },
      { id: 5, name: 'Celeritas' },
      { id: 6, name: 'Magneta' },
      { id: 7, name: 'RubberMan' },
      { id: 8, name: 'Dynama' },
      { id: 9, name: 'Dr. IQ' },
      { id: 10, name: 'Magma' },
      { id: 11, name: 'Tornado' }
    ];
    return {data};
  }
}