Angular routing for prefix with route parameter

I want to implement the user profile page. It would be simple to just use the

/profile/user123 path using:

app-routing.module

{
  path: 'profile',
  loadChildren: () => import('./modules/profile/profile.module').then(m => m.ProfileModule)
},

profile-routing.module

{
  path: ':username',
  component: ProfileComponent
},

however, I want to do some fancy URL like /@user123.

Unfortunately, I did not find any clues on how to do it. I tried the following:

app-routing.module

{
  path: '@:username',
  loadChildren: () => import('./modules/profile/profile.module').then(m => m.ProfileModule)
},

profile-routing.module

{
  path: '',
  component: ProfileComponent
},

but it didn't work.

There is only one thing that comes to my mind, which is using a Guard checking for the '@' prefix, otherwise redirect to the /not-found page.

Any ideas on how to do the routing using the "Angular" way?

Solution

You can make use of custom route matcher to achieve the expected result.

app-routing.module.ts

    {
      path: 'profile',
      loadChildren: () => import('./modules/profile/profile.module').then(m => m.ProfileModule)
    },

In profile-routing.module.ts you can specify a route by providing custom URL-matching function as:

    {
      matcher: (url) => {
        // You can have regex as per your requirement
        if (url.length === 1 && url[0].path.match(/^@[\w]+$/gm)) {
          return {
            consumed: url,
            posParams: {
              username: new UrlSegment(url[0].path.substr(1), {}) // <--- creating UrlSegment by getting rid of @ from url path
            }
          };
        }
    
        return null;
      },
      component: ProfileComponent
    }

In profile.component.ts file you can read the username as:

    username$!: Observable<string | null>;
    constructor(private activatedRoute: ActivatedRoute) { }

    ngOnInit(): void {
      this.username$ = this.activatedRoute.paramMap
        .pipe(
          map((params: ParamMap) => params.get('username'))
        );
    }

In profile.component.html you can print the username as:

    <p>
        Profile: {{username$ | async}}
    </p>

Now simply navigate to url /profile/@user123 and you should be able to get user123 as username in ProfileComponent