control: Generalize cookie and csrf handling

internal/dis/component/server.go

@@ -9,9 +9,35 @@ import (
 type Routeable interface {
 	Component
 
-	// Routes returns the routes served by this servable
-	Routes() []string
+	// Routes returns information about the routes to be handled by this Routeable
+	Routes() Routes
 
-	// HandleRoute returns the handler for the requested route
-	HandleRoute(ctx context.Context, route string) (http.Handler, error)
+	// HandleRoute returns the handler for the requested path
+	HandleRoute(ctx context.Context, path string) (http.Handler, error)
+}
+
+// Routes represents information about a single Routeable
+type Routes struct {
+	// Paths are the paths handled by this routeable.
+	// Each path is passed to HandleRoute() individually.
+	Paths []string
+
+	// CSRF indicates if this route should be protected by CSRF.
+	// CSRF protection is applied prior to any custom decorator being called.
+	CSRF bool
+
+	// Decorators is a function applied to the handler returned by HandleRoute.
+	// When nil, it is not applied.
+	Decorator func(http.Handler) http.Handler
+}
+
+// Decorate decorates the provided handler with the options specified in this handler.
+func (routes Routes) Decorate(handler http.Handler, csrf func(http.Handler) http.Handler) http.Handler {
+	if routes.CSRF && csrf != nil {
+		handler = csrf(handler)
+	}
+	if routes.Decorator != nil {
+		handler = routes.Decorator(handler)
+	}
+	return handler
 }