Custom Routing for a multi-tenant application

[LaughingJohn]

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

We have a multi tenant / multi system application. We can tell the tenant (user's AD) from the user who is signed in, but we need to distinguish the system they are accessing (org).
So I want to be able to do the following:

1. Have the org in the URL:
   https://mydomain/org1/mypage
   https://mydomain/org2/mypage
2. If the default url is chosen https://mydomain/ then we want to direct to a page that allows them to choose the org. I'm not too worried about this bit, but include it for completeness.

Describe the solution you'd like

1. I don't want to include the org as a parameter in the page route itself. So I want to be able to use @page "/mypage".
2. Ideally, when I click a navlink I want it to go the linked page with the "org" part of the url intact, without supplying it. So /mylinkedpage would go to https://mydomain/org1/mylinkedpage
3. Ideally it would be good to be able to call GetJsonAsync etc. without having to supply the org in the path.

Additional context

Is there any way of achieving this currently?
Do I have to write a custom router to do it?
If so, do you have any examples/advice on doing so?

Thank you!

[javiercn]

@LaughingJohn thanks for contacting us.

You could probably do this using the a path base per org or modifying the page routes to prepend the org parameter to them?

[LaughingJohn]

Hi @javiercn,
I think you may be right. I've updated a test page to @page "/{org}/mypage" on the Blazor client side and then changed the routing in the API to be: endpoints.MapControllerRoute("default", "{org}/{controller}/{action}"); and that seems to have done the trick (so far).

For anyone else who comes along I also had to remove the ApiController and Route attributes from the controller as well.

Thank you!

[LaughingJohn]

@javiercn, can you expand on the "base path per org" comment, is that a different alternative?

[LaughingJohn]

@javiercn, sorry another question, can I move the main layout (default page) to the {org}/ rather than just "/" ?

[LaughingJohn]

Sorry, this is becoming a bit of a diary! ;)

Regarding my previous point, I think the issue is this:

1. I navigate to https://mydomain/org/mypage1
2. mypage1 has a layout
3. The layout contains a navlink: href="mypage2"
4. Clicking that link goes to https://mydomain/mypage2

In other words the org gets lost because the layout doesn't know where it is and doesn't have access to the parameter.

I think this is a similar issue to #14077

I guess the suggestion on there of dropping the layout altogether and using a "parent" page to act as the layout is the way to go. I will try that..

[javiercn]

@LaughingJohn Sorry, I thought this was an MVC question, not a Blazor question.

Is it a blazor question or are you trying to intermix Blazor and MVC, if you provide us with more details then I can probably offer you a better answer.

[LaughingJohn]

@javiercn, sorry I didn't make that clear, yes it's a Blazor Webassembly issue. Although we may end up with some server side razor pages as well.

I think I've got there (kind of). I was hoping that there would be some way to tell the whole application that I wanted to run under a pattern url like https://mydomain/org/... Where org is the client's system name (tenant).

I was hoping that links, NavLink etc. would somehow magically work using https://mydomain/org/ as the base URI, but I think I'm being a bit naive. Apologies I'm new to both Blazor as well as ASP.Net generally, so I've been experimenting with the best way to organise our application. In the end I had to create a helper extension method to pull the org out of the current url and then insert it into the path for a link. I guess I was expecting too much of the framework.

Just in case it helps someone, I have it running like this (FYI NavLink is in the Main Layout):

            <NavLink class="nav-link" href="@(NavigationManager.ToAbsoluteUriWithOrg("counter"))">
                <span class="oi oi-plus" aria-hidden="true"></span> Counter
            </NavLink>

   public static class NavigationManagerExtensions
    {
        public static string ToAbsoluteUriWithOrg(this NavigationManager navigationManager, string newPath)
        {
            var org = navigationManager.GetOrgFromUri();
            var path = GetPathPartOrEmpty(org) + GetPathPartOrEmpty(newPath);
            return navigationManager.ToAbsoluteUri(path).ToString();
        }

        public static string GetOrgFromUri(this NavigationManager navigationManager)
        {
            var uri = new Uri(navigationManager.Uri);
            var path = uri.AbsolutePath;
            var pathParts = path.Split(new[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
            
            if (pathParts.Length > 0)
            {
                return pathParts[0];
            }
            
            return string.Empty;
        }

        private static string GetPathPartOrEmpty(string newPath)
        {
            return string.IsNullOrWhiteSpace(newPath)
                ? string.Empty
                : "/" + newPath;
        }
    }