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我在不重新加载整个站点的情况下更新子组件时遇到问题。

结构父组件是：

父组件：

<div class="overview">
  <div class="vehicle-img">
    <img src={{vehicleImg}} />
  </div>
  <div class="board">
    <div class="board-column company-overview">
      <div class="board-column-header">{{ "COMPANY_OVERVIEW.TITLE" | translate}}</div>
      <div class="board-column-content">
        <app-company-overview [companyOverviewData]="companyOverviewData"></app-company-overview>
        <div *ngIf="!companyOverviewData" class="loading">
          <app-loading></app-loading>
        </div>
      </div>
    </div>
    <div class="board-column feeds">
      <div class="board-column-header">{{ "FEEDS.TITLE" | translate}}</div>
      <div class="board-column-content">
        <app-feeds [FeedsData]="feedsData"></app-feeds>
        <div *ngIf="!feedsData" class="loading">
            <app-loading></app-loading>
      </div>
    </div>
  </div>
</div>

提要组件：


<div class="feeds">
  <mat-card class="feed-card">
    <mat-card-title>
      <div class="title">
        <h3>{{ 'FEEDS.SUBTITLE' | translate}} {{vin}}</h3>
        <hr>
      </div>
    </mat-card-title>
    <app-feed-list></app-feed-list>
    <div class="comment">
      <textarea class="textarea" matInput placeholder="Enter your comment ..." [(ngModel)]="feedsComment"></textarea>
      <button mat-button [disabled]="!feedsComment" (click)="sendComment()">
        <mat-icon class="send-button" matSuffix>send</mat-icon>
      </button>
    </div>
  </mat-card>
</div>

在这个组件中，有一个输入字段和一个按钮。如果单击该按钮，它将调用 post api 服务。将数据发送到后端。

public sendComment(): void {
    alert(this.feedsComment);
    let newFeeds = this.createFeeds();
    this.feedsService.sendFeedsComment(newFeeds).subscribe(() => {
      this.feedsService.getFeedsOverview(this.vin).subscribe((feedsData: Feeds[]) => {
        this.feedsOverviewData = feedsData;
      });
    });
  }

提要-list.html：

<div class="feed-list">
  <table mat-table [dataSource]="dataSource">
    <ng-container matColumnDef="feeds">
      <td mat-cell *matCellDef="let item">
        <mat-card-header>
          <div mat-card-avatar>
            <mat-icon class="avatar">insert_emoticon</mat-icon>
          </div>
          <mat-card-title class="feeds-header"><b>
              <div *ngIf="item.comment !== ''">
                <span>n-Level {{item.user}}</span>
              </div>
              <div *ngIf="item.comment === ''">
                <span>Event</span>
              </div>
            </b>
          </mat-card-title>
          <mat-card-subtitle class="feeds-date">{{item.date | date: 'dd/MM/yyyy'}}</mat-card-subtitle>
        </mat-card-header>
        <mat-card-content>
          <div *ngIf="item.comment !== ''">
            <div class="feeds-info">{{item.comment}}</div>
          </div>
          <div *ngIf="item.comment === ''">
            <div class="feeds-info">FIN search executed by {{item.user}}.</div>
          </div>
        </mat-card-content>
      </td>
    </ng-container>
    <tr mat-row *matRowDef="let row; columns: displayedColumns;"></tr>
  </table>
  <div class="footer">
    <mat-paginator [length]="" [pageSize]="5" [pageSizeOptions]="[5, 10, 20, 30, 40, 50]" showFirstLastButtons></mat-paginator>
  </div>
</div>

和 feeds-list.ts

export class FeedListComponent implements OnInit {
  displayedColumns: string[] = ['feeds'];
  @Input() feedsOverviewData: Feeds[];
  @ViewChild(MatPaginator) paginator: MatPaginator;
  dataSource = new MatTableDataSource<Feeds>(DATA);
  constructor() {
  }

我这个提要组件，它还有一个子组件提要列表组件

我的问题是，如果调用 sendFeedsComment 返回 200，那么是否应该在不上传整个站点的情况下将这些新评论显示在提要列表中。

我有个想法，我可以调用 api getAllFeeds 来获取所有评论，但是这个 api 会在父组件中使用。

什么是正确的实施方式

有人可以帮助我吗？

此致，

狮子座

4

1 回答 1

1

您所需要的只是 feeds-list.ts 上的 ngOnChanges，当输入参数值发生更改时，ngOnchanges 就会触发，因此在您的情况下，您的输入参数是 feedsOverviewData。这是示例。我希望它可以帮助你

提要.html

   <div class="feeds">
     <mat-card class="feed-card">
      <mat-card-title>
         <div class="title">
            <h3>{{ 'FEEDS.SUBTITLE' | translate}} {{vin}}</h3>
            <hr>
         </div>
     </mat-card-title>
     <app-feed-list  [feedsOverviewData]="feedsOverviewData"></app-feed-list>
     <div class="comment">
       <textarea class="textarea" matInput placeholder="Enter your comment ..." 
          [(ngModel)]="feedsComment"></textarea>
       <button mat-button [disabled]="!feedsComment" (click)="sendComment()">
       <mat-icon class="send-button" matSuffix>send</mat-icon>
     </button>
     </div>
     </mat-card>
     </div>

提要.ts

   public sendComment(): void {
      alert(this.feedsComment);
    let newFeeds = this.createFeeds();
    this.feedsService.sendFeedsComment(newFeeds).subscribe(() => {
       this.feedsService.getFeedsOverview(this.vin).subscribe((feedsData: Feeds[]) => 
     {
       this.feedsOverviewData = feedsData;
     });
    });
  }

提要-list.ts

   import { OnChanges, SimpleChanges } from '@angular/core';

   export class FeedListComponent implements OnInit, OnChanges {
   displayedColumns: string[] = ['feeds'];
   @Input() feedsOverviewData: Feeds[];
   @ViewChild(MatPaginator) paginator: MatPaginator;
   dataSource = new MatTableDataSource<Feeds>(DATA);

   constructor() {
   }

    ngOnChanges(changes: SimpleChanges): void {
    if (changes != null) {
         console.log(changes);
            // here you will get the updated data when ever you click the sendComment button on feeds 
     }
    }
于 2019-03-29T06:01:12.720 回答