Add a third, simple, example for folder structuring as requested at https://github.com/kataras/iris/issues/748

One change to code base but it will be described at the next version:

Error Handlers (`app.OnErrorCode/OnAnyErrorCode`)  respect the `app.UseGlobal`'s middlewares now (not the `app.Use` for reasons we can all understand, hopefully).


Former-commit-id: ec97bbb04548f9932cf4d7b950be513b70747bcb

_examples/README.md

@@ -22,6 +22,7 @@ Structuring is always depends on your needs. We can't tell you how to design you
 
 - [Example 1](mvc/login)
 - [Example 2](structuring/mvc)
+- [Example 3](structuring/handler-based)
 
 ### HTTP Listening
 

_examples/structuring/handler-based/bootstrap/bootstrapper.go

@@ -0,0 +1,113 @@
+package bootstrap
+
+import (
+	"time"
+
+	"github.com/gorilla/securecookie"
+
+	"github.com/kataras/iris"
+	"github.com/kataras/iris/sessions"
+	"github.com/kataras/iris/websocket"
+)
+
+type Configurator func(*Bootstrapper)
+
+type Bootstrapper struct {
+	*iris.Application
+	AppName      string
+	AppOwner     string
+	AppSpawnDate time.Time
+
+	Sessions *sessions.Sessions
+}
+
+// New returns a new Bootstrapper.
+func New(appName, appOwner string, cfgs ...Configurator) *Bootstrapper {
+	b := &Bootstrapper{
+		AppName:      appName,
+		AppOwner:     appOwner,
+		AppSpawnDate: time.Now(),
+		Application:  iris.New(),
+	}
+
+	for _, cfg := range cfgs {
+		cfg(b)
+	}
+
+	return b
+}
+
+// SetupViews loads the templates.
+func (b *Bootstrapper) SetupViews(viewsDir string) {
+	b.RegisterView(iris.HTML(viewsDir, ".html").Layout("shared/layout.html"))
+}
+
+// SetupSessions initializes the sessions, optionally.
+func (b *Bootstrapper) SetupSessions(expires time.Duration, cookieHashKey, cookieBlockKey []byte) {
+	b.Sessions = sessions.New(sessions.Config{
+		Cookie:   "SECRET_SESS_COOKIE_" + b.AppName,
+		Expires:  expires,
+		Encoding: securecookie.New(cookieHashKey, cookieBlockKey),
+	})
+}
+
+// SetupWebsockets prepares the websocket server.
+func (b *Bootstrapper) SetupWebsockets(endpoint string, onConnection websocket.ConnectionFunc) {
+	ws := websocket.New(websocket.Config{})
+	ws.OnConnection(onConnection)
+
+	b.Get(endpoint, ws.Handler())
+	b.Any("/iris-ws.js", func(ctx iris.Context) {
+		ctx.Write(websocket.ClientSource)
+	})
+}
+
+// SetupErrorHandlers prepares the http error handlers (>=400).
+func (b *Bootstrapper) SetupErrorHandlers() {
+	b.OnAnyErrorCode(func(ctx iris.Context) {
+		err := iris.Map{
+			"app":     b.AppName,
+			"status":  ctx.GetStatusCode(),
+			"message": ctx.Values().GetString("message"),
+		}
+
+		if jsonOutput := ctx.URLParamExists("json"); jsonOutput {
+			ctx.JSON(err)
+			return
+		}
+
+		ctx.ViewData("Err", err)
+		ctx.ViewData("Title", "Error")
+		ctx.View("shared/error.html")
+	})
+}
+
+const (
+	// StaticAssets is the root directory for public assets like images, css, js.
+	StaticAssets = "./public/"
+	// Favicon is the relative 9to the "StaticAssets") favicon path for our app.
+	Favicon = "favicon.ico"
+)
+
+// Bootstrap prepares our application.
+//
+// Returns itself.
+func (b *Bootstrapper) Bootstrap() *Bootstrapper {
+	b.SetupViews("./views")
+	b.SetupSessions(24*time.Hour,
+		[]byte("the-big-and-secret-fash-key-here"),
+		[]byte("lot-secret-of-characters-big-too"),
+	)
+	b.SetupErrorHandlers()
+
+	// static files
+	b.Favicon(StaticAssets + Favicon)
+	b.StaticWeb(StaticAssets[1:len(StaticAssets)-1], StaticAssets)
+
+	return b
+}
+
+// Listen starts the http server with the specified "addr".
+func (b *Bootstrapper) Listen(addr string, cfgs ...iris.Configurator) {
+	b.Run(iris.Addr(addr), cfgs...)
+}

_examples/structuring/handler-based/main.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"github.com/kataras/iris/_examples/structuring/handler-based/bootstrap"
+	"github.com/kataras/iris/_examples/structuring/handler-based/middleware/identity"
+	"github.com/kataras/iris/_examples/structuring/handler-based/routes"
+)
+
+var app = bootstrap.New("Awesome App", "kataras2006@hotmail.com",
+	identity.Configure,
+	routes.Configure,
+)
+
+func init() {
+	app.Bootstrap()
+}
+
+func main() {
+	app.Listen(":8080")
+}

_examples/structuring/handler-based/main_test.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/kataras/iris/httptest"
+)
+
+// TestApp runs by `$ go test -v`.
+func TestApp(t *testing.T) {
+	e := httptest.New(t, app.Application)
+
+	// test our routes
+	e.GET("/").Expect().Status(httptest.StatusOK)
+	e.GET("/follower/42").Expect().Status(httptest.StatusOK).
+		Body().Equal("from /follower/{id:long} with ID: 42")
+	e.GET("/following/52").Expect().Status(httptest.StatusOK).
+		Body().Equal("from /following/{id:long} with ID: 52")
+	e.GET("/like/64").Expect().Status(httptest.StatusOK).
+		Body().Equal("from /like/{id:long} with ID: 64")
+
+	// test not found
+	e.GET("/notfound").Expect().Status(httptest.StatusNotFound)
+	expectedErr := map[string]interface{}{
+		"app":     app.AppName,
+		"status":  httptest.StatusNotFound,
+		"message": "",
+	}
+	e.GET("/anotfoundwithjson").WithQuery("json", nil).
+		Expect().Status(httptest.StatusNotFound).JSON().Equal(expectedErr)
+}

_examples/structuring/handler-based/middleware/identity/identity.go

@@ -0,0 +1,33 @@
+package identity
+
+import (
+	"time"
+
+	"github.com/kataras/iris"
+
+	"github.com/kataras/iris/_examples/structuring/handler-based/bootstrap"
+)
+
+// New returns a new handler which adds some headers and view data
+// describing the application, i.e the owner, the startup time.
+func New(b *bootstrap.Bootstrapper) iris.Handler {
+	return func(ctx iris.Context) {
+		// response headers
+		ctx.Header("App-Name", b.AppName)
+		ctx.Header("App-Owner", b.AppOwner)
+		ctx.Header("App-Since", time.Since(b.AppSpawnDate).String())
+
+		ctx.Header("Server", "Iris: https://iris-go.com")
+
+		// view data if ctx.View or c.Tmpl = "$page.html" will be called next.
+		ctx.ViewData("AppName", b.AppName)
+		ctx.ViewData("AppOwner", b.AppOwner)
+		ctx.Next()
+	}
+}
+
+// Configure creates a new identity middleware and registers that to the app.
+func Configure(b *bootstrap.Bootstrapper) {
+	h := New(b)
+	b.UseGlobal(h)
+}

_examples/structuring/handler-based/routes/follower.go

@@ -0,0 +1,11 @@
+package routes
+
+import (
+	"github.com/kataras/iris"
+)
+
+// GetFollowerHandler handles the GET: /follower/{id}
+func GetFollowerHandler(ctx iris.Context) {
+	id, _ := ctx.Params().GetInt64("id")
+	ctx.Writef("from "+ctx.GetCurrentRoute().Path()+" with ID: %d", id)
+}

_examples/structuring/handler-based/routes/following.go

@@ -0,0 +1,11 @@
+package routes
+
+import (
+	"github.com/kataras/iris"
+)
+
+// GetFollowingHandler handles the GET: /following/{id}
+func GetFollowingHandler(ctx iris.Context) {
+	id, _ := ctx.Params().GetInt64("id")
+	ctx.Writef("from "+ctx.GetCurrentRoute().Path()+" with ID: %d", id)
+}

_examples/structuring/handler-based/routes/index.go

@@ -0,0 +1,11 @@
+package routes
+
+import (
+	"github.com/kataras/iris"
+)
+
+// GetIndexHandler handles the GET: /
+func GetIndexHandler(ctx iris.Context) {
+	ctx.ViewData("Title", "Index Page")
+	ctx.View("index.html")
+}

_examples/structuring/handler-based/routes/like.go

@@ -0,0 +1,11 @@
+package routes
+
+import (
+	"github.com/kataras/iris"
+)
+
+// GetLikeHandler handles the GET: /like/{id}
+func GetLikeHandler(ctx iris.Context) {
+	id, _ := ctx.Params().GetInt64("id")
+	ctx.Writef("from "+ctx.GetCurrentRoute().Path()+" with ID: %d", id)
+}

_examples/structuring/handler-based/routes/routes.go

@@ -0,0 +1,14 @@
+package routes
+
+import (
+	"github.com/kataras/iris/_examples/structuring/handler-based/bootstrap"
+)
+
+// Configure registers the nessecary routes to the app.
+func Configure(b *bootstrap.Bootstrapper) {
+	// routes
+	b.Get("/", GetIndexHandler)
+	b.Get("/follower/{id:long}", GetFollowerHandler)
+	b.Get("/following/{id:long}", GetFollowingHandler)
+	b.Get("/like/{id:long}", GetLikeHandler)
+}

_examples/structuring/handler-based/views/index.html

@@ -0,0 +1 @@
+<h1>Welcome!!</h1>

_examples/structuring/handler-based/views/shared/error.html

@@ -0,0 +1,5 @@
+<h1 class="text-danger">Error.</h1>
+<h2 class="text-danger">An error occurred while processing your request.</h2>
+
+<h3>{{.Err.status}}</h3>
+<h4>{{.Err.message}}</h4>

_examples/structuring/handler-based/views/shared/layout.html

@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+
+<head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <link rel="shortcut icon" type="image/x-icon" href="/favicon.ico" />
+    <title>{{.Title}} - {{.AppName}}</title>
+
+</head>
+
+<body>
+    <div>
+        <!-- Render the current template here -->
+        {{ yield }}
+        <hr />
+        <footer>
+            <p>&copy; 2017 - {{.AppOwner}}</p>
+        </footer>
+    </div>
+</body>
+
+</html>

context/context.go

@@ -364,6 +364,8 @@ type Context interface {
 	//  | Various Request and Post Data                              |
 	//  +------------------------------------------------------------+
 
+	// URLParam returns true if the url parameter exists, otherwise false.
+	URLParamExists(name string) bool
 	// URLParamDefault returns the get parameter from a request, if not found then "def" is returned.
 	URLParamDefault(name string, def string) string
 	// URLParam returns the get parameter from a request , if any.
@@ -1236,6 +1238,7 @@ func (ctx *context) ContentType(cType string) {
 			cType += "; charset=" + charset
 		}
 	}
+
 	ctx.writer.Header().Set(contentTypeHeaderKey, cType)
 }
 
@@ -1273,6 +1276,16 @@ func (ctx *context) GetStatusCode() int {
 //  | Various Request and Post Data                              |
 //  +------------------------------------------------------------+
 
+// URLParam returns true if the url parameter exists, otherwise false.
+func (ctx *context) URLParamExists(name string) bool {
+	if q := ctx.request.URL.Query(); q != nil {
+		_, exists := q[name]
+		return exists
+	}
+
+	return false
+}
+
 // URLParamDefault returns the get parameter from a request, if not found then "def" is returned.
 func (ctx *context) URLParamDefault(name string, def string) string {
 	v := ctx.request.URL.Query().Get(name)

core/router/api_builder.go

@@ -534,6 +534,12 @@ func (api *APIBuilder) Controller(relativePath string, controller activator.Base
 		api.reporter.Add("%v for path: '%s'", err, relativePath)
 	}
 
+	if cInit, ok := controller.(interface {
+		Init(activator.RegisterFunc)
+	}); ok {
+		cInit.Init(registerFunc)
+	}
+
 	return
 }
 
@@ -800,6 +806,10 @@ func (api *APIBuilder) StaticWeb(requestPath string, systemPath string) *Route {
 // and/or disable the gzip if gzip response recorder
 // was active.
 func (api *APIBuilder) OnErrorCode(statusCode int, handlers ...context.Handler) {
+	if len(api.beginGlobalHandlers) > 0 {
+		handlers = joinHandlers(api.beginGlobalHandlers, handlers)
+	}
+
 	api.errorCodeHandlers.Register(statusCode, handlers...)
 }