How to scroll with Router Navigation in Angular 7?

Question

my sidebar navigation component sidebar.component.html is like this:

<nav class="navbar navbar-expand-lg navbar-dark bg-primary fixed-top" id="sideNav">
  <a class="navbar-brand" href="#page-top">
    <span class="d-block d-lg-none">Sujoy Debnath</span>
    <span class="d-none d-lg-block">
      <img class="img-fluid img-profile rounded-circle mx-auto mb-2" src="assets/img/resume.jpg"             alt="">
    </span>
  </a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-   target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
  <span class="navbar-toggler-icon"></span>
  </button>
  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav">
      <li class="nav-item">
        <a class="nav-link" routerLink="/about">About</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" routerLink="/experience">Experience</a>
      </li>
      <li class="nav-item">
        <a class="nav-link" routerLink="/education">Education</a>
      </li>
    </ul>
  </div>
</nav>

and the sidebar.component.ts is like this:

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-sidebar',
  templateUrl: './sidebar.component.html',
  styleUrls: ['./sidebar.component.css']
})
export class SidebarComponent implements OnInit {

  constructor() { }

  ngOnInit() {
  }

}

when I click on About or Experience it Routes to those components as they are mapped in my app-routing-module.ts

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { IntroductionComponent } from './introduction/introduction.component';
import { ExperienceComponent } from './experience/experience.component';
import { EducationComponent } from './education/education.component';

const routes: Routes = [
  {path: '', redirectTo: '/about', pathMatch: 'full'},
  {path: 'about', component: IntroductionComponent},
  {path: 'experience', component: ExperienceComponent},
  {path: 'education', component: EducationComponent}

];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

my app.component.html is like this. I am calling the sidebar.component by its selector app-sidebar:

<router-outlet></router-outlet>
<app-sidebar></app-sidebar>

Now how to route the navigation by scrolling such that when I scroll down it automatically moves down from about to experience to education or when I scroll up it automatically moves up from experience to education to about sections.

Answer 1

My example code is on

1. /page1
2. /page2
3. /page3

and is activated when the wheel is used to scroll down and up, it's possible to implement the same thing that I did by adding other events (like with up and down arrow key)

In the app component, I set a window listener for wheel movement, check if the wheel is moving up or down, and last but not least navigate to the wanted route.

  constructor(
    private router: Router
  ) { }

  @HostListener('window:wheel', ['$event'])
  onWheelScroll(evento: WheelEvent) {
    // Scroll down
    if (evento.deltaY > 0) {
      switch (this.router.url) {
        case '/page1': {
          this.router.navigate(['/page2'])
          break
        }
        case '/page2': {
          this.router.navigate(['/page3'])
          break
        }
        case '/page3': {
          break
        }
      }
    } else { // Scroll up
      switch (this.router.url) {
        case '/page1': {
          break
        }
        case '/page2': {
          this.router.navigate(['/page1'])
          break
        }
        case '/page3': {
          this.router.navigate(['/page2'])
          break
        }
      }
    }
  }

This is just one of many solutions.

If you want that the event is emitted only if the wheel is scrolled inside the component you can do like this too:

introduction.component.ts

  HostListener('wheel', ['$event'])
  onWheelScroll(evento: WheelEvent) {
    // Scroll up
    if (evento.deltaY > 0) {
      this.router.navigate(['experience'])
    }
  }

experience.component.ts

  HostListener('wheel', ['$event'])
  onWheelScroll(evento: WheelEvent) {
    // Scroll down
    if (evento.deltaY > 0) {
      this.router.navigate(['education'])
    } else { // Scroll up
      this.router.navigate(['about'])
    }
  }

education.component.ts

  HostListener('wheel', ['$event'])
  onWheelScroll(evento: WheelEvent) {
    // Scroll up
    if (evento.deltaY < 0) {
      this.router.navigate(['experience'])
    }
  }