angular 5+ 相同的路由，相同的组件但不同的参数，不在 angular 订阅上发送 http get 请求

Question

This is my app.modules

const appRoutes: Routes = [
  { path: 'topic/:topicTypeAngular', component: StoryTypeComponent, pathMatch : 'full'},
  { path: '**', component: PageNotFoundComponent}
];

This is my nav in html

<ul>
    <li> <a routerLink="topic/culture">Culture</a></li>
    <li><a routerLink="topic/tech">Tech</a></li>
</ul>

// Thid is component.ts excerpt and crucial part

import { Component, OnInit } from '@angular/core';
import { HttpClient, HttpRequest, HttpEvent, HttpEventType, HttpParams } from '@angular/common/http';
import { ActivatedRoute } from '@angular/router';

   constructor(public http: HttpClient, private route: ActivatedRoute) {
         this.parameter = this.route.snapshot.paramMap.get('topicTypeAngular');
         let parameter = this.parameter;
    }


    ngOnInit() {
         this.route.url.subscribe(parameter => {
         let parameter = this.parameter;
          this.http.get('http://localhost:3200/cookbooks/topic/'+parameter).subscribe(httpResponse => {
              this.data = httpResponse;
              console.log(httpResponse);
            });

        })
     }

The last part does not provide me new httpResponse data. This link similar to my issue but not exact. However, I tried but failed. Thanks in advance

Answer 1

What about directly getting the params with a pipe like this :

constructor(public http: HttpClient, private route: ActivatedRoute) {    
  this.route.paramMap.pipe(
    switchMap((params: ParamMap) => {
      this.parameter = params.get('topicTypeAngular');
      return this.http.get(`http://localhost:3200/something/topic/${this.parameter}`);
    })
  ).subscribe(
    result => console.log(result)
  );
}

Answer 2

Try this:

constructor(public http: HttpClient, private route: ActivatedRoute) {}

    ngOnInit() {

    this.route.params.subscribe(param => this.http.get('http://localhost:3200/something/topic/' + param['topicTypeAngular']).subscribe(httpResponse => {
            this.data = httpResponse;
            console.log(httpResponse);
        });)
 }