implement #1536 with (SetRegisterRule(iris.RouteOverlap))

Former-commit-id: 2b5523ff3e2aab60dd83faa3c520b16a34916fbe

.github/ISSUE_TEMPLATE.md

@@ -8,4 +8,4 @@ Love iris? Please consider supporting the project:
 👉  https://iris-go.com/donate
 
 Care to be part of a larger community? Fill our user experience form:
-👉  https://goo.gl/forms/lnRbVgA6ICTkPyk02
+👉  https://goo.gl/forms/lnRbVgA6ICTkPyk02

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,4 +2,4 @@
 
 Read how you can [contribute to the project](https://github.com/kataras/iris/blob/master/CONTRIBUTING.md).
 
-> Please attach an [issue](https://github.com/kataras/iris/issues) link which your PR solves otherwise your work may be rejected.
+> Please attach an [issue](https://github.com/kataras/iris/issues) link which your PR solves otherwise your work may be rejected.

.github/workflows/go.yml

@@ -17,10 +17,10 @@ jobs:
         restore-keys: |
           ${{ runner.os }}-go-
 
-    - name: Set up Go 1.13
+    - name: Set up Go 1.14
       uses: actions/setup-go@v1
       with: 
-        go-version: 1.13
+        go-version: 1.14
       id: go
 
     - name: Check out code into the Go module directory

_examples/mvc/authenticated-controller/main.go

@@ -26,6 +26,11 @@ func main() {
 
 	userRouter := app.Party("/user")
 	{
+		// Use that in order to be able to register a route twice,
+		// last one will be executed if the previous route's handler(s) stopped and the response can be reset-ed.
+		// See core/router/route_register_rule_test.go#TestRegisterRuleOverlap.
+		userRouter.SetRegisterRule(iris.RouteOverlap)
+
 		// Initialize a new MVC application on top of the "userRouter".
 		userApp := mvc.New(userRouter)
 		// Register Dependencies.
@@ -34,6 +39,7 @@ func main() {
 		// Register Controllers.
 		userApp.Handle(new(MeController))
 		userApp.Handle(new(UserController))
+		userApp.Handle(new(UnauthenticatedUserController))
 	}
 
 	// Open a client, e.g. Postman and visit the below endpoints.
@@ -61,6 +67,15 @@ func authDependency(ctx iris.Context, session *sessions.Session) Authenticated {
 	return Authenticated(userID)
 }
 
+// UnauthenticatedUserController serves the "public" Unauthorized User API.
+type UnauthenticatedUserController struct{}
+
+// GetMe registers a route that will be executed when authentication is not passed
+// (see UserController.GetMe) too.
+func (c *UnauthenticatedUserController) GetMe() string {
+	return `custom action to redirect on authentication page`
+}
+
 // UserController serves the "public" User API.
 type UserController struct {
 	Session *sessions.Session

context/context.go

@@ -169,7 +169,6 @@ type Context interface {
 	SetHandlers(Handlers)
 	// Handlers keeps tracking of the current handlers.
 	Handlers() Handlers
-
 	// HandlerIndex sets the current index of the
 	// current context's handlers chain.
 	// If n < 0 or the current handlers length is 0 then it just returns the

context/gzip_response_writer.go

@@ -192,6 +192,7 @@ func (w *GzipResponseWriter) Body() []byte {
 }
 
 // ResetBody resets the response body.
+// Implements the `ResponseWriterBodyReseter`.
 func (w *GzipResponseWriter) ResetBody() {
 	w.chunks = w.chunks[0:0]
 }
@@ -202,6 +203,26 @@ func (w *GzipResponseWriter) Disable() {
 	w.disabled = true
 }
 
+// Reset disables the gzip content writer, clears headers, sets the status code to 200
+// and clears the cached body.
+//
+// Implements the `ResponseWriterReseter`.
+func (w *GzipResponseWriter) Reset() bool {
+	// disable gzip content writer.
+	w.Disable()
+	// clear headers.
+	h := w.ResponseWriter.Header()
+	for k := range h {
+		h[k] = nil
+	}
+	// restore status code.
+	w.WriteHeader(defaultStatusCode)
+	// reset body.
+	w.ResetBody()
+
+	return true
+}
+
 // FlushResponse validates the response headers in order to be compatible with the gzip written data
 // and writes the data to the underline ResponseWriter.
 func (w *GzipResponseWriter) FlushResponse() {

context/response_recorder.go

@@ -139,11 +139,15 @@ func (w *ResponseRecorder) ClearHeaders() {
 	}
 }
 
-// Reset resets the response body, headers and the status code header.
-func (w *ResponseRecorder) Reset() {
+// Reset clears headers, sets the status code to 200
+// and clears the cached body.
+//
+// Implements the `ResponseWriterReseter`.
+func (w *ResponseRecorder) Reset() bool {
 	w.ClearHeaders()
 	w.WriteHeader(defaultStatusCode)
 	w.ResetBody()
+	return true
 }
 
 // FlushResponse the full body, headers and status code to the underline response writer

context/response_writer.go

@@ -105,6 +105,32 @@ type ResponseWriter interface {
 	CloseNotifier() (http.CloseNotifier, bool)
 }
 
+// ResponseWriterBodyReseter can be implemented by
+// response writers that supports response body overriding
+// (e.g. recorder and compressed).
+type ResponseWriterBodyReseter interface {
+	// ResetBody should reset the body and reports back if it could reset successfully.
+	ResetBody()
+}
+
+// ResponseWriterDisabler can be implemented
+// by response writers that can be disabled and restored to their previous state
+// (e.g. compressed).
+type ResponseWriterDisabler interface {
+	// Disable should disable this type of response writer and fallback to the default one.
+	Disable()
+}
+
+// ResponseWriterReseter can be implemented
+// by response writers that can clear the whole response
+// so a new handler can write into this from the beginning.
+// E.g. recorder, compressed (full) and common writer (status code and headers).
+type ResponseWriterReseter interface {
+	// Reset should reset the whole response and reports
+	// whether it could reset successfully.
+	Reset() bool
+}
+
 //  +------------------------------------------------------------+
 //  | Response Writer Implementation                             |
 //  +------------------------------------------------------------+
@@ -167,6 +193,25 @@ func (w *responseWriter) EndResponse() {
 	releaseResponseWriter(w)
 }
 
+// Reset clears headers, sets the status code to 200
+// and clears the cached body.
+//
+// Implements the `ResponseWriterReseter`.
+func (w *responseWriter) Reset() bool {
+	if w.written > 0 {
+		return false // if already written we can't reset this type of response writer.
+	}
+
+	h := w.Header()
+	for k := range h {
+		h[k] = nil
+	}
+
+	w.written = NoWritten
+	w.statusCode = defaultStatusCode
+	return true
+}
+
 // SetWritten sets manually a value for written, it can be
 // NoWritten(-1) or StatusCodeWritten(0), > 0 means body length which is useless here.
 func (w *responseWriter) SetWritten(n int) {

core/handlerconv/from_std.go

@@ -18,21 +18,19 @@ func FromStd(handler interface{}) context.Handler {
 	case context.Handler:
 		{
 			//
-			// it's already a iris handler
+			// it's already an Iris Handler
 			//
 			return h
 		}
-
 	case http.Handler:
-		//
-		// handlerFunc.ServeHTTP(w,r)
-		//
 		{
+			//
+			// handlerFunc.ServeHTTP(w,r)
+			//
 			return func(ctx context.Context) {
 				h.ServeHTTP(ctx.ResponseWriter(), ctx.Request())
 			}
 		}
-
 	case func(http.ResponseWriter, *http.Request):
 		{
 			//
@@ -40,7 +38,6 @@ func FromStd(handler interface{}) context.Handler {
 			//
 			return FromStd(http.HandlerFunc(h))
 		}
-
 	case func(http.ResponseWriter, *http.Request, http.HandlerFunc):
 		{
 			//
@@ -48,7 +45,6 @@ func FromStd(handler interface{}) context.Handler {
 			//
 			return FromStdWithNext(h)
 		}
-
 	default:
 		{
 			//
@@ -60,9 +56,8 @@ func FromStd(handler interface{}) context.Handler {
 			- func(w http.ResponseWriter, r *http.Request)
 			- func(w http.ResponseWriter, r *http.Request, next http.HandlerFunc)
 			---------------------------------------------------------------------
-			It seems to be a  %T points to: %v`, handler, handler))
+			It seems to be a %T points to: %v`, handler, handler))
 		}
-
 	}
 }
 
@@ -70,10 +65,10 @@ func FromStd(handler interface{}) context.Handler {
 // compatible context.Handler wrapper.
 func FromStdWithNext(h func(w http.ResponseWriter, r *http.Request, next http.HandlerFunc)) context.Handler {
 	return func(ctx context.Context) {
-		next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		next := func(w http.ResponseWriter, r *http.Request) {
 			ctx.ResetRequest(r)
 			ctx.Next()
-		})
+		}
 
 		h(ctx.ResponseWriter(), ctx.Request(), next)
 	}

core/router/api_builder.go

@@ -91,6 +91,9 @@ func (repo *repository) register(route *Route, rule RouteRegisterRule) (*Route,
 				return r, nil
 			} else if rule == RouteError {
 				return nil, fmt.Errorf("new route: %s conflicts with an already registered one: %s route", route.String(), r.String())
+			} else if rule == RouteOverlap {
+				overlapRoute(r, route)
+				return route, nil
 			} else {
 				// replace existing with the latest one, the default behavior.
 				repo.routes = append(repo.routes[:i], repo.routes[i+1:]...)
@@ -113,6 +116,38 @@ func (repo *repository) register(route *Route, rule RouteRegisterRule) (*Route,
 	return route, nil
 }
 
+var defaultOverlapFilter = func(ctx context.Context) bool {
+	if ctx.IsStopped() {
+		// It's stopped and the response can be overriden by a new handler.
+		rs, ok := ctx.ResponseWriter().(context.ResponseWriterReseter)
+		return ok && rs.Reset()
+	}
+
+	// It's not stopped, all OK no need to execute the alternative route.
+	return false
+}
+
+func overlapRoute(r *Route, next *Route) {
+	next.BuildHandlers()
+	nextHandlers := next.Handlers[0:]
+
+	decisionHandler := func(ctx context.Context) {
+		ctx.Next()
+
+		if !defaultOverlapFilter(ctx) {
+			return
+		}
+
+		ctx.SetCurrentRoute(next.ReadOnly)
+		ctx.HandlerIndex(0)
+		ctx.Do(nextHandlers)
+	}
+
+	// NOTE(@kataras): Any UseGlobal call will prepend to this, if they are
+	// in the same Party then it's expected, otherwise not.
+	r.beginHandlers = append(context.Handlers{decisionHandler}, r.beginHandlers...)
+}
+
 // APIBuilder the visible API for constructing the router
 // and child routers.
 type APIBuilder struct {
@@ -261,10 +296,17 @@ const (
 	// RouteError log when a route already exists, shown after the `Build` state,
 	// server never starts.
 	RouteError
+	// RouteOverlap will overlap the new route to the previous one.
+	// If the route stopped and its response can be reset then the new route will be execute.
+	RouteOverlap
 )
 
 // SetRegisterRule sets a `RouteRegisterRule` for this Party and its children.
-// Available values are: RouteOverride (the default one), RouteSkip and RouteError.
+// Available values are:
+// * RouteOverride (the default one)
+// * RouteSkip
+// * RouteError
+// * RouteOverlap.
 func (api *APIBuilder) SetRegisterRule(rule RouteRegisterRule) Party {
 	api.routeRegisterRule = rule
 	return api

core/router/party.go

@@ -116,7 +116,11 @@ type Party interface {
 	// Example: https://github.com/kataras/iris/tree/master/_examples/mvc/middleware/without-ctx-next
 	SetExecutionRules(executionRules ExecutionRules) Party
 	// SetRegisterRule sets a `RouteRegisterRule` for this Party and its children.
-	// Available values are: RouteOverride (the default one), RouteSkip and RouteError.
+	// Available values are:
+	// * RouteOverride (the default one)
+	// * RouteSkip
+	// * RouteError
+	// * RouteOverlap.
 	SetRegisterRule(rule RouteRegisterRule) Party
 
 	// Handle registers a route to the server's router.

core/router/route.go

@@ -66,6 +66,9 @@ type Route struct {
 
 	// ReadOnly is the read-only structure of the Route.
 	ReadOnly context.RouteReadOnly
+
+	// OnBuild runs right before BuildHandlers.
+	OnBuild func(r *Route)
 }
 
 // NewRoute returns a new route based on its method,
@@ -186,6 +189,10 @@ func (r *Route) RestoreStatus() bool {
 // at the `Application#Build` state. Do not call it manually, unless
 // you were defined your own request mux handler.
 func (r *Route) BuildHandlers() {
+	if r.OnBuild != nil {
+		r.OnBuild(r)
+	}
+
 	if len(r.beginHandlers) > 0 {
 		r.Handlers = append(r.beginHandlers, r.Handlers...)
 		r.beginHandlers = r.beginHandlers[0:0]

core/router/route_register_rule_test.go

@@ -58,3 +58,54 @@ func testRegisterRule(e *httptest.Expect, expectedGetBody string) {
 		}
 	}
 }
+
+func TestRegisterRuleOverlap(t *testing.T) {
+	app := iris.New()
+	// TODO(@kataras) the overlapping does not work per-party yet,
+	// it just checks compares from the total app's routes (which is the best possible action to do
+	// because MVC applications can be separated into different parties too?).
+	usersRouter := app.Party("/users")
+	usersRouter.SetRegisterRule(iris.RouteOverlap)
+
+	// second handler will be executed, status will be reset-ed as well,
+	// stop without data written.
+	usersRouter.Get("/", func(ctx iris.Context) {
+		ctx.StopWithStatus(iris.StatusUnauthorized)
+	})
+	usersRouter.Get("/", func(ctx iris.Context) {
+		ctx.WriteString("data")
+	})
+
+	// first handler will be executed, no stop called.
+	usersRouter.Get("/p1", func(ctx iris.Context) {
+		ctx.StatusCode(iris.StatusUnauthorized)
+	})
+	usersRouter.Get("/p1", func(ctx iris.Context) {
+		ctx.WriteString("not written")
+	})
+
+	// first handler will be executed, stop but with data sent on default writer
+	// (body sent cannot be reset-ed here).
+	usersRouter.Get("/p2", func(ctx iris.Context) {
+		ctx.StopWithText(iris.StatusUnauthorized, "no access")
+	})
+	usersRouter.Get("/p2", func(ctx iris.Context) {
+		ctx.WriteString("not written")
+	})
+
+	// second will be executed, response can be reset-ed on recording.
+	usersRouter.Get("/p3", func(ctx iris.Context) {
+		ctx.Record()
+		ctx.StopWithText(iris.StatusUnauthorized, "no access")
+	})
+	usersRouter.Get("/p3", func(ctx iris.Context) {
+		ctx.WriteString("p3 data")
+	})
+
+	e := httptest.New(t, app)
+
+	e.GET("/users").Expect().Status(httptest.StatusOK).Body().Equal("data")
+	e.GET("/users/p1").Expect().Status(httptest.StatusUnauthorized).Body().Equal("Unauthorized")
+	e.GET("/users/p2").Expect().Status(httptest.StatusUnauthorized).Body().Equal("no access")
+	e.GET("/users/p3").Expect().Status(httptest.StatusOK).Body().Equal("p3 data")
+}

doc.go

@@ -38,7 +38,7 @@ Source code and other details for the project are available at GitHub:
 
 Current Version
 
-12.1.8
+12.2.0
 
 Installation
 

go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/iris-contrib/jade v1.1.4
 	github.com/iris-contrib/pongo2 v0.0.1
 	github.com/iris-contrib/schema v0.0.1
-	github.com/json-iterator/go v1.1.9
+	github.com/json-iterator/go v1.1.10
 	github.com/kataras/golog v0.0.18
 	github.com/kataras/neffos v0.0.16
 	github.com/kataras/pio v0.0.8
@@ -34,7 +34,7 @@ require (
 	github.com/vmihailenco/msgpack/v5 v5.0.0-alpha.2
 	go.etcd.io/bbolt v1.3.4
 	golang.org/x/crypto v0.0.0-20200510223506-06a226fb4e37
-	golang.org/x/net v0.0.0-20200506145744-7e3656a0809f
+	golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7
 	golang.org/x/text v0.3.2
 	golang.org/x/time v0.0.0-20200416051211-89c76fbcd5d1
 	gopkg.in/ini.v1 v1.57.0

iris.go

@@ -617,6 +617,9 @@ const (
 	// RouteError log when a route already exists, shown after the `Build` state,
 	// server never starts.
 	RouteError = router.RouteError
+	// RouteOverlap will overlap the new route to the previous one.
+	// If the route stopped and its response can be reset then the new route will be execute.
+	RouteOverlap = router.RouteOverlap
 )
 
 // Contains the enum values of the `Context.GetReferrer()` method,