Feature request: Provide support for options, login_hint and additional url parameters in popup overload

[gingters]

Is your feature request related to a problem? Please describe.

In an application we want to provide an option for a quick user-switch, without losing the state of the current components.
For that we'd like to open up a sign-in Popup on the AS (using auth code flow with pkce), and provide a login_hint (we know the user we want to switch to), as well as optional acr_values to the AS.

We noticed that the method that starts the login in a popup window does not accept the login_hint and also no additional url_parameters.

Describe the solution you'd like

While looking at the code we noticed that the method initLoginFlowInPopup does internally use a method that accepts both the login_hint as well as additional parameters, but does not expose these in its own signature:

https://github.com/manfredsteyer/angular-oauth2-oidc/blob/master/projects/lib/src/oauth-service.ts#L1062-L1071

It would be awesome if the method would expose at least the required, but ideally all parameters of the initLoginFlow method (additionalState, params) and pass them along.

Describe alternatives you've considered
Sadly no other idea comes to our mind ;)

Additional context
None.

We could also think of doing this ourselves and provide a PR, if you'd be willing to accept this.

[jeroenheijmans]

Makes sense to me. It'll be up to the maintainer to tag it 'pr-welcome' but I presume the popup version should support the same stuff the other one does?

[gingters]

Ideally yes. I could think of simply adding the arguments to the end and pass the expected default values if they are undefined, a bit like so so:

 public initLoginFlowInPopup(options?: { height?: number; width?: number }, additionalState: string = '', loginHint: string = '', additionalParameters: object = {}) {
    options = options || {};
    additionalParameters.display = 'popup';

    return this.createLoginUrl(
      additionalState,
      loginHint,
      this.silentRefreshRedirectUri,
      false,
      additionalParameters
    ).then(url => {

But of course this needs testing etc.

[sagialter88]

hi ,
is this issue going to be promoted?
we also need this solution to our project.

thanks a lot.