support multi-level subdomains redirect, see previous commit for the SubdomainRedirect fast solution

Former-commit-id: bc5749e46d1ae65f9d17063f3d8f2ea72510a9d8

_examples/README.md

@@ -10,7 +10,6 @@ It doesn't always contain the "best ways" but it does cover each important featu
 
 - [Hello world!](hello-world/main.go)
 - [Glimpse](overview/main.go)
-- [WWW](www/main.go)
 - [Tutorial: Online Visitors](tutorial/online-visitors/main.go)
 - [Tutorial: A Todo MVC Application using Iris and Vue.js](https://hackernoon.com/a-todo-mvc-application-using-iris-and-vue-js-5019ff870064)
 - [Tutorial: URL Shortener using BoltDB](https://medium.com/@kataras/a-url-shortener-service-using-go-iris-and-bolt-4182f0b00ae7)

_examples/subdomains/redirect/hosts

@@ -1,4 +1,4 @@
-127.0.0.1		mydomain.com
-127.0.0.1		www.mydomain.com
+127.0.0.1	mydomain.com
+127.0.0.1	www.mydomain.com
 
 # Windows: Drive:/Windows/system32/drivers/etc/hosts, on Linux: /etc/hosts

_examples/subdomains/redirect/main.go

@@ -44,6 +44,11 @@ func newApp() *iris.Application {
 	// First argument is the 'from' and second is the 'to/target'.
 	app.SubdomainRedirect(app, www)
 
+	// SubdomainRedirect works for multi-level subdomains as well:
+	// subsub := www.Subdomain("subsub") // subsub.www.mydomain.com
+	// subsub.Get("/", func(ctx iris.Context) { ctx.Writef("subdomain is: " + ctx.Subdomain()) })
+	// app.SubdomainRedirect(subsub, www)
+	//
 	// If you need to redirect any subdomain to 'www' then:
 	// app.SubdomainRedirect(app.WildcardSubdomain(), www)
 	// If you need to redirect from a subdomain to the root domain then:

core/router/path.go

@@ -129,7 +129,10 @@ func hasSubdomain(s string) bool {
 	// if not start with "/" then it should be something else,
 	// we don't assume anything else but subdomain.
 	slashIdx := strings.IndexByte(s, '/')
-	return slashIdx > 0 || s[0] == SubdomainPrefix[0] || (len(s) >= 2 && s[0:2] == SubdomainWildcardIndicator)
+	return slashIdx > 0 || // for route paths
+		s[0] == SubdomainPrefix[0] || // for route paths
+		(len(s) >= 2 && s[0:2] == SubdomainWildcardIndicator) || // for party rel path or route paths
+		(len(s) >= 2 && slashIdx != 0 && s[len(s)-1] == '.') // for party rel, i.e www., or subsub.www.
 }
 
 // splitSubdomainAndPath checks if the path has subdomain and if it's

iris.go

@@ -705,7 +705,7 @@ var ErrServerClosed = http.ErrServerClosed
 // `Listener`, `Server`, `Addr`, `TLS`, `AutoTLS` and `Raw`.
 func (app *Application) Run(serve Runner, withOrWithout ...Configurator) error {
 	// first Build because it doesn't need anything from configuration,
-	// this give the user the chance to modify the router inside a configurator as well.
+	// this gives the user the chance to modify the router inside a configurator as well.
 	if err := app.Build(); err != nil {
 		return errors.PrintAndReturnErrors(err, app.logger.Errorf)
 	}