Sign in
Skip to solution
mediumFrontend

How do you read route parameters?

415 views
01

Understand the problem

Explain ActivatedRoute.

routingparams
02

Attempt it yourself

Sketch your approach before reading the solution — that's what interviews test.

Nudge consolestandby

Stuck? Beam a request up — the console returns a conceptual nudge that guides your logic without spoiling the implementation.

03

Study the solution

Inject ActivatedRoute and read paramMap/queryParamMap as observables (or snapshots). Observables are preferred when the same component is reused across param changes, so you react to navigation without re-instantiating.

Solution ready — 2 min read

Classified // press E to declassify

04

Read the code

Reactive param reading + refetch
import { Component, inject } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import { switchMap } from 'rxjs';

@Component({ selector: 'app-user', standalone: true, template: '{{ id }}' })
export class UserComponent {
  private route = inject(ActivatedRoute);
  id = '';

  constructor() {
    // one-time:
    this.id = this.route.snapshot.paramMap.get('id') ?? '';

    // reactive (param changes in place) — refetch on each id:
    this.route.paramMap
      .pipe(switchMap(p => fetch('/users/' + p.get('id')).then(r => r.json())))
      .subscribe(user => console.log(user));
  }
}
05

Join the discussion

Discussion (0)

Sign in to join the discussion.

No responses yet. Be the first to share what you think.

Transmission complete // awaiting log

KEEP THE
STREAK ALIVE.

Dossier 61 of 121 decoded in the Angular track. One more won't hurt.

Back to track