OidcClientInitiatedLogoutSuccessHandler should understand redirect uri placeholders #7900
Description
OAuth 2.0 Login supports placeholders like baseUrl and registrationId.
OAuth 2.0 Logout should support these as well.
The design of ClientRegistrationRepository is intended to support multi-tenancy. In cases where each tenant has different branding, for example, it's reasonable that an application would want to ensure the redirect has the necessary information to render an appropriate post-logout experience.
A simple example is when doing multi-tenancy by path, e.g. https://foo.com/bar where bar is a reference to the tenant. For the post logout redirect uri, it's reasonable to want to do:
OidcClientInitiatedLogoutSuccessHandler handler =
new OidcClientInitiatedLogoutSuccessHandler();
handler.setPostLogoutRedirectUri("{baseUrl}/{registrationId}");so that the post logout redirect uri is resolved to https://foo.com/bar without requiring a custom implementation.