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/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...)
+}