How do I implement "redirect to where it come" mode ?

from http://angularapp.com/abc/def , redirect to authentication server http://myauth.com/<authorization_endpoint> after login redirect back to http://angularapp.com/spa-callbak
I hope that this url have previous url as querystring like http://angularapp.com/spa-callbak?returnurl=/abc/def so I can perform a redirect.

Am I use this lib incorrectly ? I have flow issues for now:

1. url /spa-callback is a compontent that have “this.router.navigate([”/“]);” inside ngOnInit() but only get 50% change to automatice goto ~/
2. a component show’s user’s name , but some time there no value

my authentication server is IdentityServer4, to load user data i put this line in AppModule

this.oauthService.configure(authConfig);
        this.oauthService.tokenValidationHandler = new JwksValidationHandler();
        this.oauthService.loadDiscoveryDocumentAndLogin()
            .then(x => {
                if (x) {
                    this.oauthService.loadUserProfile();
                }
            });

[John0King]

@jeroenheijmans I’m sorry for my bad english and Happy Mid-autumn festival 😄
I will try again with your solution after the holiday . and meantime I will close this issue.

[John0King]

@jeroenheijmans I tryed your solution , I have a suggestion about loadDiscoveryDocumentAndLogin(), I hope that this method save the url by default , and

this.oauthService.initImplicitFlow(encodeURIComponent(targetUrl || this.router.url));
// abouve code  this.router.url doesn't work, it always point to `/`

I used `(from @angular/common)Location.path(true)` to get current url

this is my final code :

this.oauthService.configure(authConfig);
        this.oauthService.tokenValidationHandler = new JwksValidationHandler();
        this.oauthService.loadDiscoveryDocument()
            .then(doc => {
                this.oauthService.tryLogin({
                    onTokenReceived: (context) => {
                        console.log("token received");
                        this.oauthService.loadUserProfile()
                            .then(cliams => {
                                console.log("profile loaded")
                                let preUrl = this.oauthService.state;
                                console.log("state:" + typeof (preUrl) + ":" + preUrl);
                                if (preUrl == null || preUrl == "") {
                                    preUrl = "/"
                                }
                                console.log("navigate to " + preUrl + ".....");
                                this.router.navigateByUrl(preUrl)
                                console.log("navigateed");

                            });
                    }
                })
                    .then(() => {
                        if (!this.oauthService.hasValidAccessToken()) {
                            let currentUrl = this._location.path(true);
                            console.log("initImplicit with :" + currentUrl);
                            this.oauthService.initImplicitFlow(currentUrl);
                        }
                    })
            });