New feature: versioning.Aliases

Thanks @mulyawansentosa and @remopavithran for your donates ❤️

HISTORY.md

@@ -28,6 +28,29 @@ The codebase for Dependency Injection, Internationalization and localization and
 
 ## Fixes and Improvements
 
+- New `versioning.Aliases` middleware. Example Code:
+
+```go
+app := iris.New()
+
+api := app.Party("/api")
+api.Use(Aliases(map[string]string{
+    versioning.Empty: "1", // when no version was provided by the client.
+    "beta": "4.0.0",
+    "stage": "5.0.0-alpha"
+}))
+
+v1 := NewGroup(api, ">= 1, < 2")
+v1.Get/Post...
+
+v4 := NewGroup(api, ">= 4, < 5")
+v4.Get/Post...
+
+stage := NewGroup(api, "5.0.0-alpha")
+stage.Get/Post...
+```
+
+- New [Basic Authentication](https://github.com/kataras/iris/tree/master/middleware/basicauth) middleware. Its `Default` function has not changed, however, the rest, e.g. `New` contains breaking changes as the new middleware features new functionalities.
 - Add `iris.DirOptions.SPA bool` field to allow [Single Page Applications](https://github.com/kataras/iris/tree/master/_examples/file-server/single-page-application/basic/main.go) under a file server.
 - A generic User interface, see the `Context.SetUser/User` methods in the New Context Methods section for more. In-short, the basicauth middleware's stored user can now be retrieved through `Context.User()` which provides more information than the native `ctx.Request().BasicAuth()` method one. Third-party authentication middleware creators can benefit of these two methods, plus the Logout below. 
 - A `Context.Logout` method is added, can be used to invalidate [basicauth](https://github.com/kataras/iris/blob/master/_examples/auth/basicauth/basic/main.go) or [jwt](https://github.com/kataras/iris/blob/master/_examples/auth/jwt/blocklist/main.go) client credentials.

README.md

@@ -36,6 +36,8 @@ With your help, we can improve Open Source web development for everyone!
 > Donations from **China** are now accepted!
 
 <p>
+  <a href="https://github.com/remopavithran"><img src="https://avatars1.githubusercontent.com/u/50388068?v=4" alt ="Pavithran" title="remopavithran" with="75" style="width:75px;max-width:75px;height:75px" height="75" /></a>
+  <a href="https://github.com/mulyawansentosa"><img src="https://avatars1.githubusercontent.com/u/29946673?v=4" alt ="MULYAWAN SENTOSA" title="mulyawansentosa" with="75" style="width:75px;max-width:75px;height:75px" height="75" /></a>
   <a href="https://github.com/TianJIANG"><img src="https://avatars1.githubusercontent.com/u/158459?v=4" alt ="KIT UNITED" title="TianJIANG" with="75" style="width:75px;max-width:75px;height:75px" height="75" /></a>
   <a href="https://github.com/rhernandez-itemsoft"><img src="https://avatars1.githubusercontent.com/u/4327356?v=4" alt ="Ricardo Hernandez Lopez" title="rhernandez-itemsoft" with="75" style="width:75px;max-width:75px;height:75px" height="75" /></a>
   <a href="https://github.com/ChinChuanKuo"><img src="https://avatars1.githubusercontent.com/u/11756978?v=4" alt ="ChinChuanKuo" title="ChinChuanKuo" with="75" style="width:75px;max-width:75px;height:75px" height="75" /></a>

_examples/auth/basicauth/basic/main.go

@@ -64,14 +64,11 @@ func main() {
 }
 
 func handler(ctx iris.Context) {
-	// username, password, _ := ctx.Request().BasicAuth()
-	// third parameter it will be always true because the middleware
-	// makes sure for that, otherwise this handler will not be executed.
-	// OR:
-	user := ctx.User()
-	// OR ctx.User().GetRaw() to get the underline value.
-	username, _ := user.GetUsername()
-	password, _ := user.GetPassword()
+	// user := ctx.User().(*myUserType)
+	// or ctx.User().GetRaw().(*myUserType)
+	// ctx.Writef("%s %s:%s", ctx.Path(), user.Username, user.Password)
+	// OR if you don't have registered custom User structs:
+	username, password, _ := ctx.Request().BasicAuth()
 	ctx.Writef("%s %s:%s", ctx.Path(), username, password)
 }
 

_examples/routing/basic/main.go

@@ -152,7 +152,7 @@ func newApp() *iris.Application {
 	}
 
 	// wildcard subdomains.
-	wildcardSubdomain := app.Party("*.")
+	wildcardSubdomain := app.WildcardSubdomain()
 	{
 		wildcardSubdomain.Get("/", func(ctx iris.Context) {
 			ctx.Writef("Subdomain can be anything, now you're here from: %s", ctx.Subdomain())

_examples/routing/main.go

@@ -82,11 +82,11 @@ func registerGamesRoutes(app *iris.Application) {
 }
 
 func registerSubdomains(app *iris.Application) {
-	mysubdomain := app.Party("mysubdomain.")
+	mysubdomain := app.Subdomain("mysubdomain")
 	// http://mysubdomain.myhost.com
 	mysubdomain.Get("/", h)
 
-	willdcardSubdomain := app.Party("*.")
+	willdcardSubdomain := app.WildcardSubdomain()
 	willdcardSubdomain.Get("/", h)
 	willdcardSubdomain.Party("/party").Get("/", h)
 }

_examples/routing/overview/main.go

@@ -116,7 +116,7 @@ func main() {
 	adminRoutes.Get("/settings", info)
 
 	// Wildcard/dynamic subdomain
-	dynamicSubdomainRoutes := app.Party("*.")
+	dynamicSubdomainRoutes := app.WildcardSubdomain()
 
 	// GET: http://any_thing_here.localhost:8080
 	dynamicSubdomainRoutes.Get("/", info)

_examples/routing/subdomains/wildcard/main.go

@@ -33,7 +33,7 @@ func main() {
 	}*/
 
 	// no order, you can register subdomains at the end also.
-	dynamicSubdomains := app.Party("*.")
+	dynamicSubdomains := app.WildcardSubdomain()
 	{
 		dynamicSubdomains.Get("/", dynamicSubdomainHandler)
 

_examples/routing/versioning/main.go

@@ -45,10 +45,12 @@ func examplePerParty(app *iris.Application) {
 	// You can customize the way a version is extracting
 	// via middleware, for example:
 	// version url parameter, and, if it's missing we default it to "1".
-	usersAPI.Use(func(ctx iris.Context) {
-		versioning.SetVersion(ctx, ctx.URLParamDefault("version", "1"))
-		ctx.Next()
-	})
+	// usersAPI.Use(func(ctx iris.Context) {
+	// 	versioning.SetVersion(ctx, ctx.URLParamDefault("version", "1"))
+	// 	ctx.Next()
+	// })
+	// OR:
+	usersAPI.Use(versioning.FromQuery("version", "1"))
 
 	// version 1.
 	usersAPIV1 := versioning.NewGroup(usersAPI, ">= 1, < 2")

_examples/sessions/overview/example/example.go

@@ -114,7 +114,7 @@ func NewApp(sess *sessions.Sessions) *iris.Application {
 	app.Get("/delete", func(ctx iris.Context) {
 		session := sessions.Get(ctx)
 		// delete a specific key
-		session.Delete("name")
+		session.Delete("username")
 	})
 
 	app.Get("/clear", func(ctx iris.Context) {

_examples/sessions/securecookie/main_test.go

@@ -16,12 +16,12 @@ func TestSessionsEncodeDecode(t *testing.T) {
 	es.Cookies().NotEmpty()
 	es.Body().Equal("All ok session set to: iris [isNew=true]")
 
-	e.GET("/get").Expect().Status(iris.StatusOK).Body().Equal("The name on the /set was: iris")
+	e.GET("/get").Expect().Status(iris.StatusOK).Body().Equal("The username on the /set was: iris")
 	// delete and re-get
 	e.GET("/delete").Expect().Status(iris.StatusOK)
-	e.GET("/get").Expect().Status(iris.StatusOK).Body().Equal("The name on the /set was: ")
+	e.GET("/get").Expect().Status(iris.StatusOK).Body().Equal("The username on the /set was: ")
 	// set, clear and re-get
 	e.GET("/set").Expect().Body().Equal("All ok session set to: iris [isNew=false]")
 	e.GET("/clear").Expect().Status(iris.StatusOK)
-	e.GET("/get").Expect().Status(iris.StatusOK).Body().Equal("The name on the /set was: ")
+	e.GET("/get").Expect().Status(iris.StatusOK).Body().Equal("The username on the /set was: ")
 }

_examples/testing/httptest/main.go

@@ -37,6 +37,11 @@ func h(ctx iris.Context) {
 	// third parameter it will be always true because the middleware
 	// makes sure for that, otherwise this handler will not be executed.
 	// OR:
+	//
+	// user := ctx.User().(*myUserType)
+	// ctx.Writef("%s %s:%s", ctx.Path(), user.Username, user.Password)
+	// OR if you don't have registered custom User structs:
+	//
 	// ctx.User().GetUsername()
 	// ctx.User().GetPassword()
 	ctx.Writef("%s %s:%s", ctx.Path(), username, password)

_examples/view/template_html_4/main.go

@@ -27,7 +27,7 @@ func main() {
 	// wildcard subdomain, will catch username1.... username2.... username3... username4.... username5...
 	// that our below links are providing via page.html's first argument which is the subdomain.
 
-	subdomain := app.Party("*.")
+	subdomain := app.WildcardSubdomain()
 
 	mypathRoute := subdomain.Get("/mypath", emptyHandler)
 	mypathRoute.Name = "my-page1"

configuration.go

@@ -767,6 +767,11 @@ type Configuration struct {
 	// via a middleware through `SetVersion` method, e.g. `versioning.SetVersion(ctx, "1.0, 1.1")`.
 	// Defaults to "iris.api.version".
 	VersionContextKey string `ini:"version_context_key" json:"versionContextKey" yaml:"VersionContextKey" toml:"VersionContextKey"`
+	// VersionAliasesContextKey is the context key which the versioning feature
+	// can look up for alternative values of a version and fallback to that.
+	// Head over to the versioning package for more.
+	// Defaults to "iris.api.version.aliases"
+	VersionAliasesContextKey string `ini:"version_aliases_context_key" json:"versionAliasesContextKey" yaml:"VersionAliasesContextKey" toml:"VersionAliasesContextKey"`
 	// ViewEngineContextKey is the context's values key
 	// responsible to store and retrieve(view.Engine) the current view engine.
 	// A middleware or a Party can modify its associated value to change
@@ -974,6 +979,11 @@ func (c Configuration) GetVersionContextKey() string {
 	return c.VersionContextKey
 }
 
+// GetVersionAliasesContextKey returns the VersionAliasesContextKey field.
+func (c Configuration) GetVersionAliasesContextKey() string {
+	return c.VersionAliasesContextKey
+}
+
 // GetViewEngineContextKey returns the ViewEngineContextKey field.
 func (c Configuration) GetViewEngineContextKey() string {
 	return c.ViewEngineContextKey
@@ -1132,6 +1142,10 @@ func WithConfiguration(c Configuration) Configurator {
 			main.VersionContextKey = v
 		}
 
+		if v := c.VersionAliasesContextKey; v != "" {
+			main.VersionAliasesContextKey = v
+		}
+
 		if v := c.ViewEngineContextKey; v != "" {
 			main.ViewEngineContextKey = v
 		}
@@ -1205,16 +1219,17 @@ func DefaultConfiguration() Configuration {
 		// The request body the size limit
 		// can be set by the middleware `LimitRequestBodySize`
 		// or `context#SetMaxRequestBodySize`.
-		PostMaxMemory:           32 << 20, // 32MB
-		LocaleContextKey:        "iris.locale",
-		LanguageContextKey:      "iris.locale.language",
-		LanguageInputContextKey: "iris.locale.language.input",
-		VersionContextKey:       "iris.api.version",
-		ViewEngineContextKey:    "iris.view.engine",
-		ViewLayoutContextKey:    "iris.view.layout",
-		ViewDataContextKey:      "iris.view.data",
-		RemoteAddrHeaders:       nil,
-		RemoteAddrHeadersForce:  false,
+		PostMaxMemory:            32 << 20, // 32MB
+		LocaleContextKey:         "iris.locale",
+		LanguageContextKey:       "iris.locale.language",
+		LanguageInputContextKey:  "iris.locale.language.input",
+		VersionContextKey:        "iris.api.version",
+		VersionAliasesContextKey: "iris.api.version.aliases",
+		ViewEngineContextKey:     "iris.view.engine",
+		ViewLayoutContextKey:     "iris.view.layout",
+		ViewDataContextKey:       "iris.view.data",
+		RemoteAddrHeaders:        nil,
+		RemoteAddrHeadersForce:   false,
 		RemoteAddrPrivateSubnets: []netutil.IPRange{
 			{
 				Start: "10.0.0.0",

context/configuration.go

@@ -53,6 +53,8 @@ type ConfigurationReadOnly interface {
 	GetLanguageInputContextKey() string
 	// GetVersionContextKey returns the VersionContextKey field.
 	GetVersionContextKey() string
+	// GetVersionAliasesContextKey returns the VersionAliasesContextKey field.
+	GetVersionAliasesContextKey() string
 
 	// GetViewEngineContextKey returns the ViewEngineContextKey field.
 	GetViewEngineContextKey() string

context/context_user.go

@@ -81,15 +81,15 @@ to the end-developer's custom implementations.
 
 // SimpleUser is a simple implementation of the User interface.
 type SimpleUser struct {
-	Authorization string          `json:"authorization,omitempty"`
-	AuthorizedAt  time.Time       `json:"authorized_at,omitempty"`
-	ID            string          `json:"id,omitempty"`
-	Username      string          `json:"username,omitempty"`
-	Password      string          `json:"password,omitempty"`
-	Email         string          `json:"email,omitempty"`
-	Roles         []string        `json:"roles,omitempty"`
-	Token         json.RawMessage `json:"token,omitempty"`
-	Fields        Map             `json:"fields,omitempty"`
+	Authorization string          `json:"authorization,omitempty" db:"authorization"`
+	AuthorizedAt  time.Time       `json:"authorized_at,omitempty" db:"authorized_at"`
+	ID            string          `json:"id,omitempty" db:"id"`
+	Username      string          `json:"username,omitempty" db:"username"`
+	Password      string          `json:"password,omitempty" db:"password"`
+	Email         string          `json:"email,omitempty" db:"email"`
+	Roles         []string        `json:"roles,omitempty" db:"roles"`
+	Token         json.RawMessage `json:"token,omitempty" db:"token"`
+	Fields        Map             `json:"fields,omitempty" db:"fields"`
 }
 
 var _ User = (*SimpleUser)(nil)

context/handler.go

@@ -239,6 +239,10 @@ var ignoreMainHandlerNames = [...]string{
 	"iris.reCAPTCHA",
 	"iris.profiling",
 	"iris.recover",
+	"iris.accesslog",
+	"iris.grpc",
+	"iris.requestid",
+	"iris.rewrite",
 }
 
 // ingoreMainHandlerName reports whether a main handler of "name" should

context/route.go

@@ -62,6 +62,10 @@ type RouteReadOnly interface {
 	// MainHandlerIndex returns the first registered handler's index for the route.
 	MainHandlerIndex() int
 
+	// Property returns a specific property based on its "key"
+	// of this route's Party owner.
+	Property(key string) (interface{}, bool)
+
 	// Sitemap properties: https://www.sitemaps.org/protocol.html
 
 	// GetLastMod returns the date of last modification of the file served by this route.

core/router/api_builder.go

@@ -196,6 +196,11 @@ type APIBuilder struct {
 
 	// the api builder global macros registry
 	macros *macro.Macros
+	// the per-party (and its children) values map
+	// that may help on building the API
+	// when source code is splitted between projects.
+	// Initialized on Properties method.
+	properties context.Map
 	// the api builder global routes repository
 	routes *repository
 	// disables the debug logging of routes under a per-party and its children.
@@ -624,7 +629,7 @@ func (api *APIBuilder) createRoutes(errorCode int, methods []string, relativePat
 	routes := make([]*Route, len(methods))
 
 	for i, m := range methods { // single, empty method for error handlers.
-		route, err := NewRoute(errorCode, m, subdomain, path, routeHandlers, *api.macros)
+		route, err := NewRoute(api, errorCode, m, subdomain, path, routeHandlers, *api.macros)
 		if err != nil { // template path parser errors:
 			api.logger.Errorf("[%s:%d] %v -> %s:%s:%s", filename, line, err, m, subdomain, path)
 			continue
@@ -668,19 +673,21 @@ func removeDuplicates(elements []string) (result []string) {
 
 // Party returns a new child Party which inherites its
 // parent's options and middlewares.
-// If "relativePath" matches the parent's one then it returns the current Party.
 // A Party groups routes which may have the same prefix or subdomain and share same middlewares.
 //
 // To create a group of routes for subdomains
 // use the `Subdomain` or `WildcardSubdomain` methods
-// or pass a "relativePath" as "admin." or "*." respectfully.
+// or pass a "relativePath" of "admin." or "*." respectfully.
 func (api *APIBuilder) Party(relativePath string, handlers ...context.Handler) Party {
 	// if app.Party("/"), root party or app.Party("/user") == app.Party("/user")
 	// then just add the middlewares and return itself.
-	if relativePath == "" || api.relativePath == relativePath {
-		api.Use(handlers...)
-		return api
-	}
+	// if relativePath == "" || api.relativePath == relativePath {
+	// 	api.Use(handlers...)
+	// 	return api
+	// }
+	// ^ No, this is wrong, let the developer do its job, if she/he wants a copy let have it,
+	// it's a pure check as well, a path can be the same even if it's the same as its parent, i.e.
+	// app.Party("/user").Party("/user") should result in a /user/user, not a /user.
 
 	parentPath := api.relativePath
 	dot := string(SubdomainPrefix[0])
@@ -712,10 +719,17 @@ func (api *APIBuilder) Party(relativePath string, handlers ...context.Handler) P
 	allowMethods := make([]string, len(api.allowMethods))
 	copy(allowMethods, api.allowMethods)
 
+	// make a copy of the parent properties.
+	var properties map[string]interface{}
+	for k, v := range api.properties {
+		properties[k] = v
+	}
+
 	childAPI := &APIBuilder{
 		// global/api builder
 		logger:              api.logger,
 		macros:              api.macros,
+		properties:          properties,
 		routes:              api.routes,
 		routesNoLog:         api.routesNoLog,
 		beginGlobalHandlers: api.beginGlobalHandlers,
@@ -808,6 +822,16 @@ func (api *APIBuilder) Macros() *macro.Macros {
 	return api.macros
 }
 
+// Properties returns the original Party's properties map,
+// it can be modified before server startup but not afterwards.
+func (api *APIBuilder) Properties() context.Map {
+	if api.properties == nil {
+		api.properties = make(context.Map)
+	}
+
+	return api.properties
+}
+
 // GetRoutes returns the routes information,
 // some of them can be changed at runtime some others not.
 //
@@ -1096,6 +1120,8 @@ func (api *APIBuilder) DoneGlobal(handlers ...context.Handler) {
 
 // RemoveHandler deletes a handler from begin and done handlers
 // based on its name or the handler pc function.
+// Note that UseGlobal and DoneGlobal handlers cannot be removed
+// through this method as they were registered to the routes already.
 //
 // As an exception, if one of the arguments is a pointer to an int,
 // then this is used to set the total amount of removed handlers.

core/router/party.go

@@ -39,6 +39,10 @@ type Party interface {
 	// Learn more at:  https://github.com/kataras/iris/tree/master/_examples/routing/dynamic-path
 	Macros() *macro.Macros
 
+	// Properties returns the original Party's properties map,
+	// it can be modified before server startup but not afterwards.
+	Properties() context.Map
+
 	// SetRoutesNoLog disables (true) the verbose logging for the next registered
 	// routes under this Party and its children.
 	//

core/router/route.go

@@ -19,6 +19,8 @@ import (
 // If any of the following fields are changed then the
 // caller should Refresh the router.
 type Route struct {
+	// The Party which this Route was created and registered on.
+	Party       Party
 	Title       string         `json:"title"`       // custom name to replace the method on debug logging.
 	Name        string         `json:"name"`        // "userRoute"
 	Description string         `json:"description"` // "lists a user"
@@ -86,7 +88,7 @@ type Route struct {
 // handlers and the macro container which all routes should share.
 // It parses the path based on the "macros",
 // handlers are being changed to validate the macros at serve time, if needed.
-func NewRoute(statusErrorCode int, method, subdomain, unparsedPath string,
+func NewRoute(p Party, statusErrorCode int, method, subdomain, unparsedPath string,
 	handlers context.Handlers, macros macro.Macros) (*Route, error) {
 	tmpl, err := macro.Parse(unparsedPath, macros)
 	if err != nil {
@@ -110,6 +112,7 @@ func NewRoute(statusErrorCode int, method, subdomain, unparsedPath string,
 	formattedPath := formatPath(path)
 
 	route := &Route{
+		Party:         p,
 		StatusCode:    statusErrorCode,
 		Name:          defaultName,
 		Method:        method,
@@ -583,6 +586,8 @@ type routeReadOnlyWrapper struct {
 	*Route
 }
 
+var _ context.RouteReadOnly = routeReadOnlyWrapper{}
+
 func (rd routeReadOnlyWrapper) StatusErrorCode() int {
 	return rd.Route.StatusCode
 }
@@ -619,6 +624,17 @@ func (rd routeReadOnlyWrapper) MainHandlerIndex() int {
 	return rd.Route.MainHandlerIndex
 }
 
+func (rd routeReadOnlyWrapper) Property(key string) (interface{}, bool) {
+	properties := rd.Route.Party.Properties()
+	if properties != nil {
+		if property, ok := properties[key]; ok {
+			return property, true
+		}
+	}
+
+	return nil, false
+}
+
 func (rd routeReadOnlyWrapper) GetLastMod() time.Time {
 	return rd.Route.LastMod
 }

hero/reflect.go

@@ -18,7 +18,7 @@ func valueOf(v interface{}) reflect.Value {
 
 // indirectType returns the value of a pointer-type "typ".
 // If "typ" is a pointer, array, chan, map or slice it returns its Elem,
-// otherwise returns the typ as it's.
+// otherwise returns the "typ" as it is.
 func indirectType(typ reflect.Type) reflect.Type {
 	switch typ.Kind() {
 	case reflect.Ptr, reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:

middleware/accesslog/accesslog.go

@@ -327,7 +327,7 @@ func File(path string) *AccessLog {
 	return New(bufio.NewReadWriter(bufio.NewReader(f), bufio.NewWriter(f)))
 }
 
-// FileUnbuffered same as File but it does not buffers the data,
+// FileUnbuffered same as File but it does not buffer the data,
 // it flushes the loggers contents as soon as possible.
 func FileUnbuffered(path string) *AccessLog {
 	f := mustOpenFile(path)

sessions/sessiondb/boltdb/database.go

@@ -339,14 +339,14 @@ func (db *Database) Visit(sid string, cb func(key string, value interface{})) er
 }
 
 // Len returns the length of the session's entries (keys).
-func (db *Database) Len(sid string) (n int64) {
+func (db *Database) Len(sid string) (n int) {
 	err := db.Service.View(func(tx *bolt.Tx) error {
 		b := db.getBucketForSession(tx, sid)
 		if b == nil {
 			return nil
 		}
 
-		n = int64(b.Stats().KeyN)
+		n = int(int64(b.Stats().KeyN))
 		return nil
 	})
 

versioning/deprecation.go

@@ -6,10 +6,17 @@ import (
 	"github.com/kataras/iris/v12/context"
 )
 
+// The response header keys when a resource is deprecated by the server.
+const (
+	APIWarnHeader            = "X-Api-Warn"
+	APIDeprecationDateHeader = "X-Api-Deprecation-Date"
+	APIDeprecationInfoHeader = "X-Api-Deprecation-Info"
+)
+
 // DeprecationOptions describes the deprecation headers key-values.
-// - "X-API-Warn": options.WarnMessage
-// - "X-API-Deprecation-Date": context.FormatTime(ctx, options.DeprecationDate))
-// - "X-API-Deprecation-Info": options.DeprecationInfo
+// - "X-Api-Warn": options.WarnMessage
+// - "X-Api-Deprecation-Date": context.FormatTime(ctx, options.DeprecationDate))
+// - "X-Api-Deprecation-Info": options.DeprecationInfo
 type DeprecationOptions struct {
 	WarnMessage     string
 	DeprecationDate time.Time
@@ -37,14 +44,14 @@ func WriteDeprecated(ctx *context.Context, options DeprecationOptions) {
 		options.WarnMessage = DefaultDeprecationOptions.WarnMessage
 	}
 
-	ctx.Header("X-API-Warn", options.WarnMessage)
+	ctx.Header(APIWarnHeader, options.WarnMessage)
 
 	if !options.DeprecationDate.IsZero() {
-		ctx.Header("X-API-Deprecation-Date", context.FormatTime(ctx, options.DeprecationDate))
+		ctx.Header(APIDeprecationDateHeader, context.FormatTime(ctx, options.DeprecationDate))
 	}
 
 	if options.DeprecationInfo != "" {
-		ctx.Header("X-API-Deprecation-Info", options.DeprecationInfo)
+		ctx.Header(APIDeprecationInfoHeader, options.DeprecationInfo)
 	}
 }
 

versioning/group.go

@@ -5,6 +5,11 @@ import (
 	"github.com/kataras/iris/v12/core/router"
 )
 
+// Property to be defined inside the registered
+// Party on NewGroup, useful for a party to know its (optional) version
+// when the versioning feature is used.
+const Property = "iris.party.version"
+
 // API is a type alias of router.Party.
 // This is required in order for a Group instance
 // to implement the Party interface without field conflict.
@@ -20,16 +25,24 @@ type Group struct {
 	deprecation DeprecationOptions
 }
 
-// NewGroup returns a ptr to Group based on the given "version".
-// It sets the API Version for the "r" Party.
+// NewGroup returns a ptr to Group based on the given "version" constraint.
+// Group completes the Party interface.
+// The returned Group wraps a cloned Party of the given "r" Party therefore,
+// any changes to its parent won't affect this one (e.g. register global middlewares afterwards).
 //
-// See `Handle` for more.
-//
-// Example: _examples/routing/versioning
+// Examples at: _examples/routing/versioning
 // Usage:
-//  api := versioning.NewGroup(Parent_Party, ">= 1, < 2")
-//  api.Get/Post/Put/Delete...
+//  app := iris.New()
+//  api := app.Party("/api")
+//  v1 := versioning.NewGroup(api, ">= 1, < 2")
+//  v1.Get/Post/Put/Delete...
+//
+// See the `GetVersion` function to learn how
+// a version is extracted and matched over this.
 func NewGroup(r router.Party, version string) *Group {
+	r = r.Party("/")
+	r.Properties()[Property] = version
+
 	// Note that this feature alters the RouteRegisterRule to RouteOverlap
 	// the RouteOverlap rule does not contain any performance downside
 	// but it's good to know that if you registered other mode, this wanna change it.
@@ -54,3 +67,21 @@ func (g *Group) Deprecated(options DeprecationOptions) *Group {
 	})
 	return g
 }
+
+// FromQuery is a simple helper which tries to
+// set the version constraint from a given URL Query Parameter.
+// The X-Api-Version is still valid.
+func FromQuery(urlQueryParameterName string, defaultVersion string) context.Handler {
+	return func(ctx *context.Context) {
+		version := ctx.URLParam(urlQueryParameterName)
+		if version == "" {
+			version = defaultVersion
+		}
+
+		if version != "" {
+			SetVersion(ctx, version)
+		}
+
+		ctx.Next()
+	}
+}

versioning/version.go

@@ -8,28 +8,26 @@ import (
 )
 
 const (
+	// APIVersionResponseHeader the response header which its value contains
+	// the normalized semver matched version.
+	APIVersionResponseHeader = "X-Api-Version"
 	// AcceptVersionHeaderKey is the header key of "Accept-Version".
 	AcceptVersionHeaderKey = "Accept-Version"
 	// AcceptHeaderKey is the header key of "Accept".
 	AcceptHeaderKey = "Accept"
 	// AcceptHeaderVersionValue is the Accept's header value search term the requested version.
 	AcceptHeaderVersionValue = "version"
-
-	// Key is the context key of the version, can be used to manually modify the "requested" version.
-	// Example of how you can change the default behavior to extract a requested version (which is by headers)
-	// from a "version" url parameter instead:
-	// func(ctx iris.Context) { // &version=1
-	// 	ctx.Values().Set(versioning.Key, ctx.URLParamDefault("version", "1"))
-	// 	ctx.Next()
-	// }
-	//
-	// DEPRECATED: Use:
-	// version := ctx.URLParamDefault("version", "1")
-	// versioning.SetVersion(ctx, version) instead.
-	Key = "iris.api.version"
 	// NotFound is the key that can be used inside a `Map` or inside `ctx.SetVersion(versioning.NotFound)`
-	// to tell that a version wasn't found, therefore the not found handler should handle the request instead.
+	// to tell that a version wasn't found, therefore the `NotFoundHandler` should handle the request instead.
 	NotFound = "iris.api.version.notfound"
+	// Empty is just an empty string. Can be used as a key for a version alias
+	// when the requested version of a resource was not even specified by the client.
+	// The difference between NotFound and Empty is important when version aliases are registered:
+	// - A NotFound cannot be registered as version alias, it
+	//   means that the client sent a version with its request
+	//   but that version was not implemented by the server.
+	// - An Empty indicates that the client didn't send any version at all.
+	Empty = ""
 )
 
 // ErrNotFound reports whether a requested version
@@ -107,7 +105,113 @@ func GetVersion(ctx *context.Context) string {
 
 // SetVersion force-sets the API Version.
 // It can be used inside a middleware.
+// Example of how you can change the default behavior to extract a requested version (which is by headers)
+// from a "version" url parameter instead:
+//  func(ctx iris.Context) { // &version=1
+//   version := ctx.URLParamDefault("version", "1")
+//   versioning.SetVersion(ctx, version)
+// 	 ctx.Next()
+//  }
 // See `GetVersion` too.
 func SetVersion(ctx *context.Context, constraint string) {
 	ctx.Values().Set(ctx.Application().ConfigurationReadOnly().GetVersionContextKey(), constraint)
 }
+
+// AliasMap is just a type alias of the standard map[string]string.
+// Head over to the `Aliases` function below for more.
+type AliasMap = map[string]string
+
+// Aliases is a middleware which registers version constraint aliases
+// for the children Parties(routers). It's respected by versioning Groups.
+//
+// Example Code:
+//  app := iris.New()
+//
+//  api := app.Party("/api")
+//  api.Use(Aliases(map[string]string{
+//   versioning.Empty: "1", // when no version was provided by the client.
+//   "beta": "4.0.0",
+//   "stage": "5.0.0-alpha"
+//  }))
+//
+//  v1 := NewGroup(api, ">= 1, < 2")
+//  v1.Get/Post...
+//
+//  v4 := NewGroup(api, ">= 4, < 5")
+//  v4.Get/Post...
+//
+//  stage := NewGroup(api, "5.0.0-alpha")
+//  stage.Get/Post...
+func Aliases(aliases AliasMap) context.Handler {
+	cp := make(AliasMap, len(aliases)) // copy the map here so we are safe of later modifications by end-dev.
+	for k, v := range aliases {
+		cp[k] = v
+	}
+
+	return func(ctx *context.Context) {
+		SetVersionAliases(ctx, cp, true)
+		ctx.Next()
+	}
+}
+
+// GetVersionAlias returns the version alias of the given "gotVersion"
+// or empty. It Reports whether the alias was found.
+// See `SetVersionAliases`, `Aliases` and `Match` for more.
+func GetVersionAlias(ctx *context.Context, gotVersion string) (string, bool) {
+	key := ctx.Application().ConfigurationReadOnly().GetVersionAliasesContextKey()
+	if key == "" {
+		return "", false
+	}
+
+	v := ctx.Values().Get(key)
+	if v == nil {
+		return "", false
+	}
+
+	aliases, ok := v.(AliasMap)
+	if !ok {
+		return "", false
+	}
+
+	version, ok := aliases[gotVersion]
+	if !ok {
+		return "", false
+	}
+
+	return strings.TrimSpace(version), true
+}
+
+// SetVersionAliases sets a map of version aliases when a requested
+// version of a resource was not implemented by the server.
+// Can be used inside a middleware to the parent Party
+// and always before the child versioning groups (see `Aliases` function).
+//
+// The map's key (string) should be the "got version" (by the client)
+// and the value should be the "version constraint to match" instead.
+// The map's value(string) should be a registered version
+// otherwise it will hit the NotFoundHandler (501, "version not found" by default).
+//
+// The given "aliases" is a type of standard map[string]string and
+// should NOT be modified afterwards.
+//
+// The last "override" input argument indicates whether any
+// existing aliases, registered by previous handlers in the chain,
+// should be overriden or copied to the previous map one.
+func SetVersionAliases(ctx *context.Context, aliases AliasMap, override bool) {
+	key := ctx.Application().ConfigurationReadOnly().GetVersionAliasesContextKey()
+	if key == "" {
+		return
+	}
+
+	v := ctx.Values().Get(key)
+	if v == nil || override {
+		ctx.Values().Set(key, aliases)
+		return
+	}
+
+	if existing, ok := v.(AliasMap); ok {
+		for k, v := range aliases {
+			existing[k] = v
+		}
+	}
+}

versioning/version_test.go

@@ -46,3 +46,53 @@ func TestGetVersion(t *testing.T) {
 
 	e.GET("/manual").Expect().Status(iris.StatusOK).Body().Equal("11.0.5")
 }
+
+func TestVersionAliases(t *testing.T) {
+	app := iris.New()
+
+	api := app.Party("/api")
+	api.Use(versioning.Aliases(map[string]string{
+		versioning.Empty: "1",
+		"stage":          "2",
+	}))
+
+	writeVesion := func(ctx iris.Context) {
+		ctx.WriteString(versioning.GetVersion(ctx))
+	}
+
+	// A group without registration order.
+	v3 := versioning.NewGroup(api, ">= 3, < 4")
+	v3.Get("/", writeVesion)
+
+	v1 := versioning.NewGroup(api, ">= 1, < 2")
+	v1.Get("/", writeVesion)
+
+	v2 := versioning.NewGroup(api, ">= 2, < 3")
+	v2.Get("/", writeVesion)
+
+	api.Get("/manual", func(ctx iris.Context) {
+		versioning.SetVersion(ctx, "12.0.0")
+		ctx.Next()
+	}, writeVesion)
+
+	e := httptest.New(t, app)
+
+	// Make sure the SetVersion still works.
+	e.GET("/api/manual").Expect().Status(iris.StatusOK).Body().Equal("12.0.0")
+
+	// Test Empty default.
+	e.GET("/api").WithHeader(versioning.AcceptVersionHeaderKey, "").Expect().
+		Status(iris.StatusOK).Body().Equal("1.0.0")
+	// Test NotFound error, aliases are not responsible for that.
+	e.GET("/api").WithHeader(versioning.AcceptVersionHeaderKey, "4").Expect().
+		Status(iris.StatusNotImplemented).Body().Equal("version not found")
+	// Test "stage" alias.
+	e.GET("/api").WithHeader(versioning.AcceptVersionHeaderKey, "stage").Expect().
+		Status(iris.StatusOK).Body().Equal("2.0.0")
+	// Test version 2.
+	e.GET("/api").WithHeader(versioning.AcceptVersionHeaderKey, "2").Expect().
+		Status(iris.StatusOK).Body().Equal("2.0.0")
+	// Test version 3 (registered first).
+	e.GET("/api").WithHeader(versioning.AcceptVersionHeaderKey, "3.1").Expect().
+		Status(iris.StatusOK).Body().Equal("3.1.0")
+}

versioning/versioning.go

@@ -14,6 +14,10 @@ func If(v string, is string) bool {
 }
 
 func check(v string, is string) (string, bool) {
+	if v == "" {
+		return "", false
+	}
+
 	ver, err := version.NewVersion(v)
 	if err != nil {
 		return "", false
@@ -31,16 +35,30 @@ func check(v string, is string) (string, bool) {
 // Match acts exactly the same as `If` does but instead it accepts
 // a Context, so it can be called by a handler to determinate the requested version.
 //
-// If matched then it sets the "X-API-Version" response header and
+// If matched then it sets the "X-Api-Version" response header and
 // stores the matched version into Context (see `GetVersion` too).
+//
+// See the `Aliases` function to register version constraint
+// aliases for a versioning Party, extremely useful when a Group is used.
 func Match(ctx *context.Context, expectedVersion string) bool {
-	versionString, matched := check(GetVersion(ctx), expectedVersion)
+	gotVersion := GetVersion(ctx)
+
+	alias, aliasFound := GetVersionAlias(ctx, gotVersion)
+	if aliasFound {
+		SetVersion(ctx, alias) // set the version so next routes have it already.
+		gotVersion = alias
+	}
+
+	versionString, matched := check(gotVersion, expectedVersion)
 	if !matched {
 		return false
 	}
 
-	SetVersion(ctx, versionString)
-	ctx.Header("X-API-Version", versionString)
+	if !aliasFound { // don't lose any time to set if already set.
+		SetVersion(ctx, versionString)
+	}
+
+	ctx.Header(APIVersionResponseHeader, versionString)
 	return true
 }
 
@@ -77,6 +95,7 @@ func NewMatcher(versions Map) context.Handler {
 
 	return func(ctx *context.Context) {
 		versionString := GetVersion(ctx)
+
 		if versionString == "" || versionString == NotFound {
 			notFoundHandler(ctx)
 			return
@@ -90,7 +109,7 @@ func NewMatcher(versions Map) context.Handler {
 
 		for _, ch := range constraintsHandlers {
 			if ch.constraints.Check(ver) {
-				ctx.Header("X-API-Version", ver.String())
+				ctx.Header(APIVersionResponseHeader, ver.String())
 				ch.handler(ctx)
 				return
 			}