angular - switchMap Angular /

Question

我将我的角度升级到 ng7。我正在做一个项目，我有 3 个 http 调用，它们相互依赖，所以我选择使用 switchMap。我的问题是，我之前编写 switchMap 的方式不起作用。这是我平时写的

DeleteConfirm(id: number, $event) {
console.log('product');
this.productService.deleteProductById(
  id).switchMap(productDeleted => this.productService.getProducts())
  .subscribe(
    products => {
      this.products = products;
      this.confirmDelete = false;
    }, error2 => {}
  );
$event.stopPropagation();

}

下面的方法是我现在正在研究的方法。关于我应该如何使用 switchMap 的任何建议？

createCompWithGroup(competitionName: string) {

return this.apiService.createACompetition(competitionName)
  .pipe(switchMap(data => {
    const competition = data['category'];
    const competitionSlug = competition.id + '-' + competition.slug;
     this.createSecurityGroup(competitionSlug).subscribe( data =>{
   return   this.addSecurityGroup(competitionName, competitionSlug)
     }
  }
  ));

}

Answer 1

这应该这样做：

createCompWithGroup(competitionName: string) {
  return this.apiService.createACompetition(competitionName).pipe(
    switchMap(data => this
      .addSecurityGroup(competitionName, `${data.cateogry.id}-${data.cateogry.slug}`)
    )
  )
}

该subscribe参数将是addSecurityGroup请求的响应。