addRouting method
Adds a routing function to the server.
The router function returns a Future containing a list of FinchRoute based on the provided Request.
This allows for dynamic routing based on the request.
Returns the FinchApp instance to allow method chaining.
Implementation
FinchApp addRouting(Future<List<FinchRoute>> Function(Request rq) router) {
_webRoutes.add(router);
return this;
}