angular - 如何创建一个 canActivate 保护以仅允许来自另一个组件的重定向？

Question

I have a component that I wish to allow it's access only in case of a redirect from another component.
So if I put the url in the browser it wouldn't allow me to access it but, if I redirect to it from another specific component like this it will be allowed:

this.router.navigate(['/main/myLockedComponent']);

I thought of adding a canActivate guard similar to an authGuard like so:

import { Injectable } from '@angular/core';
import { ActivatedRouteSnapshot, CanActivate, RouterStateSnapshot, UrlTree } from '@angular/router';
import { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class ValidationGuardService implements CanActivate{

  constructor() { }
  canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): boolean  {
    console.log(route);
    console.log(state);
    return true;
  }
}

but by printing state and route I can't find the information I need like whether this component was redirected to internally from an angular component (and better yet from which component) or not .

Edit: I am using angular 11.

Answer 1

If you want to check if you are redirected from a route like this www.testsite.com/main/profile , you could write a condition inside your guard as

import { Injectable } from '@angular/core';
import { CanActivate, Router} from '@angular/router';
import { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class ValidationGuardService implements CanActivate{

  constructor(private router : Router) { }
  canActivate(): boolean  {

    let currentUrl = this.router.url;
    let isFromProfile = currentUrl.indexOf('/profile') == -1 ? false : true;
    console.log(currentUrl);
    if(isFromProfile)
       return true;
    else 
       return false;
    }
}

You could also use the below method to check whether the last part of the url is the one we are expecting:

let isFromProfile = this.router.url.split('/').pop() === 'profile';

Hope this answered your question:-)