Routing enhancements

[SteveSandersonMS]

This issue is to track routing features we're likely to want to add in the future:

• Review exactly which parameter constraints we really want to support. For example maybe add regex; maybe remove bool or limit the set of datetime formats more precisely. See Basic route constraints (:int, etc.) blazor#295 for more discussion.
• Catch-all segments (e.g., /products/{*categoryAndName})
• 404 handler (it's probably not enough just to have a component that matches /{*anythingElse}, because for SSR you'd want to know it's really not a match so you could actually return a 404) - Done!
• Simple method for accessing querystring/hash values (e.g., via new properties on IUriHelper)
• Multiple nested routers
• Outbound URL generation (e.g., <a page=@About>About us</a>, or perhaps just by codegenning methods like <a href=@Products.Url(53)>Duck boots</a> for each @page declaration)
• In the @page directive, allow the use of compile-time constant expressions, not just literal strings (e.g., https://github.com/aspnet/blazor/issues/1363).
• Optional route parameters

Also the items from dotnet/blazor#636 that were not yet finalised:

• Discover [Route] attributes on types in referenced assemblies that themselves reference Microsoft.AspNetCore.Blazor transitively
• Discover [Route] attributes on component base classes (i.e., inherit=true)
• In the Router component, make it simple to subclass and override a virtual method to change the logic for locating the IComponent for a given URL. Currently there's no virtual method for this.
• Make RouteTable's Routes property get-only
• Cache route tables per assembly

[kristapsstrals]

@SteveSandersonMS Thanks for raising this!

[grahamehorner]

is a routine regex constraint on the road map?

[SteveSandersonMS]

Regex constraints: definitely maybe :) We're not in a rush to put in all possible constraints because in practice it's rare that you really need them, so they end up just being friction for developers. It's often only server-side API endpoints that need to be strict about that. It's a matter of seeing what scenarios evolve and what kinds of feature requests we're getting from a wide range of people.

[dlr1]

Would it be possible to define all the routes and destinations in a single place like in other JS frameworks?

[conficient]

@dlr1 I believe the routing engine is pluggable so you can replace with any other system you desire.

[Nathan-Ryan]

@dlr1 with the ability to nest routes too, perhaps similar to the way angular works with the router-outlet component.

[TheAifam5]

Also saving states for every route would be nice feature to have ;)

[bastienJS]

Please replace 'Multiple nested routers' with 'Unlimited nested routers' else we get the same dilemma they found out later in angular 2 that the router`s nesting skills were limited to sth. like 3 child routers :P

[dlr1]

It would be nice to have some virtual methods that are called at appropriate time to either allow navigation to a page or to dis-allow navigation from a page

[DNF-SaS]

@SteveSandersonMS
Is it possible to restrict the routing from a certain slug onwards?
(e.g. everything below http://myserver/blazor will be processed, but e.g. http://myserver/otherdata won't?)

[danroth27]

@DNF-SaS I believe your looking for support for catch-all segments, which hasn't been implemented yet.

[conficient]

Is there anything tracking how routes behave if a user is unauthenticated vs authenticated? In MVC we can use filters on controllers to create secure routes and insecure routes.

[danroth27]

@conficient Not currently.

[rpedretti]

I'm building a Bing Maps component and it generates lots of anchor tags with href="#". As of version 0.5.1 whenever I click any of those links i get redirected to /. Is there a way to proper handle this?

[RyoukoKonpaku]

@rpedretti for now you don't have a choice but to use JS interop since stopping the click even to propagate isn't possible yet and is tracked here #1073. If I remember you'd need the event that called the click and prevent it propagating via event.stopPropagation() method.