Add fallback handlers

Former-commit-id: f7e9bd17076a10e1ed1702780d7ce9e89f00b592

context/context.go

@@ -905,6 +905,9 @@ type Context interface {
 	// It's for extreme use cases, 99% of the times will never be useful for you.
 	Exec(method string, path string)
 
+	// RouteExists checks if a route exists
+	RouteExists(method string, path string) bool
+
 	// Application returns the iris app instance which belongs to this context.
 	// Worth to notice that this function returns an interface
 	// of the Application, which contains methods that are safe
@@ -3130,6 +3133,11 @@ func (ctx *context) Exec(method string, path string) {
 	}
 }
 
+// RouteExists checks if a route exists
+func (ctx *context) RouteExists(method string, path string) bool {
+	return ctx.Application().RouteExists(method, path, ctx)
+}
+
 // Application returns the iris app instance which belongs to this context.
 // Worth to notice that this function returns an interface
 // of the Application, which contains methods that are safe