Angular - Issue with routerLink and state

Question

From an html page I want to route to another page using routerLink and state. There's no issues with <a> tag, during ngOnInit in landing page, I can retrieve state as expected. Using <button> tag home page is navigate as well but state results undefined.

What's my wrong?

html of login page

<button routerLink="/home" [state]="navExtra.state">
    Go Home Page via button
</button>
<a routerLink="/home" [state]="navExtra.state">Go Home Page via a</a>

ts of login page

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

@Component({
  selector: 'app-login',
  templateUrl: './login.page.html',
  styleUrls: ['./login.page.scss']
})
export class LoginPage implements OnInit {
  navExtra: NavigationExtras = {
    state: { data: { a: 'a', b: 'b' } }
  };
  constructor() {}

  ngOnInit() {}
}

ts of home page

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

@Component({
  selector: 'app-home',
  templateUrl: './home.page.html',
  styleUrls: ['./home.page.scss']
})
export class HomePage implements OnInit {
  constructor(
    private router: Router
  ) {}

  ngOnInit() {
    console.log(this.router.getCurrentNavigation().extras.state);
  }
}

Answer 1

I don't think it is possible to pass state through a button. If we inspect the source code of routerLink, we can see...

when not an a tag:

@Directive({selector: ':not(a):not(area)[routerLink]'})

state isn't included in extras:

@HostListener('click')
onClick(): boolean {
  const extras = {
    skipLocationChange: attrBoolValue(this.skipLocationChange),
    replaceUrl: attrBoolValue(this.replaceUrl),
  };
  this.router.navigateByUrl(this.urlTree, extras);
  return true;
}

source

whereas when we have an a tag:

@Directive({selector: 'a[routerLink],area[routerLink]'})

it is included:

@HostListener('click', [/** .... **/])
onClick(/** .... **/): boolean {
  // .....
  const extras = {
    skipLocationChange: attrBoolValue(this.skipLocationChange),
    replaceUrl: attrBoolValue(this.replaceUrl),
    state: this.state // <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< here!
  };
  this.router.navigateByUrl(this.urlTree, extras);
  return false;
}

source

So your option is to style that link to look like a button, or then call a function on button click which performs the navigation, like presented in other answer, here I kindly refer to that code posted by AbolfazlR:

this.router.navigate(['home'], this.navExtra);