数据仅在刷新后显示 [英] Data only displayed after refresh

问题描述

我正在我的应用程序中创建评论部分，当用户输入评论并提交时，评论应立即显示在前端，不幸的是，现在只有在刷新后才能看到评论，

I am creating comments section in my app, when a user enter a comments and submit, comment should imeaditely be displayed in front end, unfortunately now comments are only visible after refresh,

这就是我所拥有的:

显示评论

component.ts

component.ts

  ngOnInit() {
       this.activeRouter.params.subscribe((params) => {
      // tslint:disable-next-line:prefer-const
      let id = params['id'];
      this.moviesService.getComments(id)
        .subscribe(comments => {
          console.log(comments);
          this.comments = comments;
        });
    });
}

service.ts

service.ts

 getComments(id: string): Observable<any> {
    const url = `${apiUrl + this.commentsUrl}/${id}`;
    return this.http.get(url, httpOptions).pipe(
      map(this.extractData),
      catchError(this.handleError));
  }

HTML

<div *ngFor="let comment of comments" class="col-md-7">
          <ul class="list-group">
            <li class="list-group-item">Author: {{comment.author}}</li>
            <li class="list-group-item">Comments: {{comment.description}}</li>
          </ul>
          <br>
        </div>

**

添加评论:

Adding comments:

** service.ts

** service.ts

  // Adds comments
      addReview(author, description) {
        const uri = 'http://localhost:8000/movies/comments';
        const obj = {
          author: author,
          description: description
        };
        return this.http.post(uri, obj);
      }

compo.ts

  createForm() {
    this.angForm = this.fb.group({
      author: ['', Validators.required],
      description: ['', Validators.required]
    });
  }
  addReview(author, description) {
    this.moviesService.addReview(author, description).subscribe(success => {
      this.flashMessages.show('You are data we succesfully submitted', { cssClass: 'alert-success', timeout: 3000 });
    }, error => {
      this.flashMessages.show('Something went wrong', { cssClass: 'alert-danger', timeout: 3000 });
    });
  }

HTML

<div class="col-md-7 movie-form" >
          <flash-messages></flash-messages>
          <form [formGroup]="angForm" novalidate>
            <div class="form-group">
              <label class="col-md-4">Author</label>
              <input type="text" class="form-control" name="author" formControlName="author" #author />
            </div>
            <div *ngIf="angForm.controls['author'].invalid && (angForm.controls['author'].dirty || angForm.controls['author'].touched)"
              class="alert alert-danger">
              <div *ngIf="angForm.controls['author'].errors.required">
                Name is required.
              </div>
            </div>
            <div class="form-group">
              <label class="col-md-4">Description</label>
              <textarea cols="10" rows="10" type="text" class="form-control" formControlName="description" #description>
                </textarea>
            </div>
            <div *ngIf="angForm.controls['description'].invalid && (angForm.controls['description'].dirty || angForm.controls['description'].touched)"
              class="alert alert-danger">
              <div *ngIf="angForm.controls['description'].errors.required">
                description is required.
              </div>
            </div>
            <div class="form-group">
              <button (click)="addReview(author.value, description.value)" [disabled]="angForm.pristine || angForm.invalid" class="btn btn-primary">Add</button>
            </div>
          </form>
        </div>

问题

Question

我的代码是什么?任何帮助建议都会被重视

what is wrog with my code? any help suggestion will be apreciated

推荐答案

您必须在提交评论的回调中调用getComments方法.您的代码在组件的ngOnInit方法中仅具有获取"调用.因此，当刷新视图时，ngOnInit会再次执行，从而调用getComments.

You have to call your getComments method in the callback of you submit comments. Your code only has a "get" call in ngOnInit method of the component. So when you refresh your view, the ngOnInit executes again and thus getComments is called.

您必须在您的Submit comments方法的回调中进行一次get调用.

You have to make a get call in the callback of your submit comments method.

EDIT#1:

addReview(author, description) {
    this.moviesService.addReview(author, description).subscribe(success => {
        this.flashMessages.show('You are data we succesfully submitted', { cssClass: 'alert-success', timeout: 3000 });
        // get the id
        this.moviesService.getComments(id).subscribe(comments => {
            console.log(comments);
            this.comments = comments;
        });
    }, error => {
        this.flashMessages.show('Something went wrong', { cssClass: 'alert-danger', timeout: 3000 });
    });
}

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