Angular Material 2 数据表连接到 AngularFire2 或 Firebase 服务？

Question

我希望它只是即插即用 :-) 我已经为此折腾了几个小时，但我的小实验都没有成功。 md数据表是新的，所以网上几乎没有什么神学知识。找到一种将 Firebase 连接到表格的好方法将是一个好的开始。有什么想法吗？

目前我有这个设置。我的代码在没有带有标准 Angular 设置和代码的表的情况下运行良好，使用 ngFor 并从模板创建列表。因此代码使用 AngularFire 2 从 Firebase 传送数据。尝试新的 md 数据表是问题所在。

首先，模板不会呈现。我知道我已经正确设置了 NgModule，所以我怀疑数据源没有连接并产生了这个错误。这是 Chrome 控制台中的错误。

Template parse errors:
Can't bind to 'dataSource' since it isn't a known property of 'md-table'.
1. If 'md-table' is an Angular component and it has 'dataSource' input, then verify that it is part of this module.

除了我更改了模板绑定(bind)之外，我的 members-search.component.html 看起来与官方文档相同:

<md-table #table [dataSource]="dataSource">

<ng-container cdkColumnDef="memberName">
    <md-header-cell *cdkHeaderCellDef> Name </md-header-cell>
    <md-cell *cdkCellDef="let row"> {{member.firstName}} {{ member?.lastName }} </md-cell>
</ng-container>

members-search.component.ts 具有以下相关部分:

import { DataSource } from '@angular/cdk';

@Injectable()
export class MembersAdminService {

  private members$: FirebaseListObservable<Member[]>;
  private dataSource: DataSource<any>;

  constructor(
      private af: AngularFireDatabase,
      @Inject(FirebaseApp) fb) {
        this.members$ = af.list('Members');
  }

我将这些数据表函数放到了 members-search.service.ts 中的工作代码中，并在 connect() 中使用了我一直在该服务的其他地方使用的相同代码。

// md table dataSource functions.
  public connect(): FirebaseListObservable<any> {
    return this.af.list('Members', {
        query: {
            orderByChild: 'lastName'
        }
    });
    // return this._exampleDatabase.dataChange;
  }

  public disconnect() {}

数据表文档和 plunker 在组件中创建数据源和数据库，但如果我已经拥有 Firebase，那么其中大部分似乎都不是必需的。我正在学习所有这些，所以我远不是任何方面的专家，也许我遗漏了一些东西。

如果您之前没有接触过这个新设置，那么这里是文档。 md 表建立在 cdk 表之上，为 cdk 表提供样式。

https://material.angular.io/components/table/overview

https://material.angular.io/guide/cdk-table

Answer 1

我添加了在使用 MD 数据表的 MD 分页器时连接到 Firebase 的代码。 Paginator 使服务中的代码更加复杂。大多数代码都在它所属的服务中。享受吧!

成员-admin.service.ts

import { AngularFireDatabase, FirebaseListObservable } from 'angularfire2/database';
import { FirebaseApp } from 'angularfire2';
import { Inject, Injectable } from '@angular/core';

import { MemberModel } from './member-admin.model';
import { SuccessService } from '../../../shared/success.service';

// Data Table imports.
import { MdPaginator } from '@angular/material';
import { DataSource } from '@angular/cdk';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/of';
import { BehaviorSubject } from 'rxjs/BehaviorSubject';
import 'rxjs/add/operator/startWith';
import 'rxjs/add/observable/merge';
import 'rxjs/add/observable/combineLatest';
import 'rxjs/add/operator/map';


@Injectable()
export class MembersAdminService {

  private membersData$: FirebaseListObservable<MemberModel[]>;

  constructor(
    public af: AngularFireDatabase,
    private successService: SuccessService,

    // For Create and Update functions.
    @Inject(FirebaseApp) fb) {
      this.membersData$ = af.list('Members');
    }

// ... CRUD stuff not relevant to the MD Table ...


// *** MD DATA TABLE SERVICES. ***


@Injectable()
export class MemberDatabase {

    /* Stream that emits whenever the data has been modified. */
    public dataChange: BehaviorSubject<MemberModel[]> = new BehaviorSubject<MemberModel[]>([]);
    get data(): MemberModel[] {
        return this.dataChange.value; }

    // Connection to remote db.
    private database = this.memberAdminService.af.list('Members', {
        query: {
            orderByChild: 'lastName'
        }
    });
    public getMembers(): FirebaseListObservable<MemberModel[]> {
        return this.database;
    }


    constructor(private memberAdminService: MembersAdminService) {
        this.getMembers()
            .subscribe(data => this.dataChange.next(data));
    }
}


@Injectable()
export class MembersAdminSource extends DataSource<MemberModel> {


    constructor(
        private memberDatabase: MemberDatabase,
        private paginator: MdPaginator) {
        super();
    }


    /** Connect function called by the table to retrieve one stream containing the data to render. */
    connect(): Observable<MemberModel[]> {

      const displayDataChanges = [
          this.memberDatabase.dataChange,
          this.paginator.page,
      ];

      return Observable
          .merge(...displayDataChanges) // Convert object to array with spread syntax.
          .map(() => {
              const dataSlice = this.memberDatabase.data.slice(); // Data removed from viewed page.

              // Get the page's slice per pageSize setting.
              const startIndex = this.paginator.pageIndex * this.paginator.pageSize;

              const dataLength = this.paginator.length;  // This is for the counter on the DOM.

              return dataSlice.splice(startIndex, this.paginator.pageSize);
          });
    }
    disconnect() {}
}

所有成员.component.ts

在 ngOnInit 和类属性中进行了一些重构。

import { Component, OnInit, ViewChild } from '@angular/core';
import { Router } from '@angular/router';
import { Subject } from 'rxjs/Subject';

// For MD Data Table.
import { MdPaginator } from '@angular/material';
import { MembersAdminService, MembersAdminSource, MemberDatabase } from './member-admin.service';

import { ConfirmService } from '../../../shared/confirm.service';
import { MemberModel } from './member-admin.model';


@Component({
  selector: 'app-all-members',
  templateUrl: './all-members.component.html'
})


export class AllMembersComponent implements OnInit {

  membersData: MemberModel[];
  private result: boolean;
  allMembers: MemberModel[];

  // For search
  startAt = new Subject();
  endAt = new Subject();
  lastKeypress: 0;

    // For MD data table.

  // private memberDatabase = new MemberDatabase();  // Requires a param but? Moved to constructor.
  private dataSource: MembersAdminSource | null;
  private displayedColumns = [
      'firstName',
      'lastName',
      'mainSkillTitle',
      'mainSkills',
      'delete',
      'key'
  ];

  @ViewChild(MdPaginator)
  paginator: MdPaginator;

  public dataLength: any; // For member counter on DOM.

  constructor(
      private membersAdminService: MembersAdminService,
      private memberDatabase: MemberDatabase,
      private router: Router,
      private confirmService: ConfirmService
  ) {}

  ngOnInit() {

      this.memberDatabase.getMembers()
          .subscribe(members => {
              this.dataSource = new MembersAdminSource(this.memberDatabase, this.paginator);
              this.dataLength = members;
          });
    }

所有成员.component.html

请注意，我在行中有用于删除和编辑的按钮，它们工作正常。诀窍是您需要隐藏列中的数据库 key 。

<md-table #table [dataSource]="dataSource">

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

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

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

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

      <!-- Delete Buttons Column -->
      <ng-container cdkColumnDef="delete">
        <md-header-cell *cdkHeaderCellDef> Delete / Edit </md-header-cell>
        <md-cell *cdkCellDef="let row">
          <button (click)="deleteMember(row.$key)">Delete</button>
          <button (click)="goToDetailPage(row.$key)">Edit</button>
        </md-cell>
      </ng-container>

      <!-- Database key Column -->

      <ng-container cdkColumnDef="key">
        <md-header-cell *cdkHeaderCellDef class="hiddenField"> Key </md-header-cell>
        <md-cell *cdkCellDef="let row" class="hiddenField"> {{row.$key}} </md-cell>
      </ng-container>


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


    </md-table>
    <md-paginator #paginator
                  [length]="dataLength?.length"
                  [pageIndex]="0"
                  [pageSize]="5"
                  [pageSizeOptions]="[5, 10, 25, 100]">
    </md-paginator>