rewrite middleware: add PrimarySubdomain and simplify its usage example

_examples/routing/rewrite/main.go

@@ -7,45 +7,23 @@ import (
 
 func main() {
 	app := iris.New()
-
-	/*
-		rewriteOptions := rewrite.Options{
-			RedirectMatch: []string{
-				"301 /seo/(.*) /$1",
-				"301 /docs/v12(.*) /docs",
-				"301 /old(.*) /",
-			}}
-		OR Load from file:
-	*/
-	rewriteOptions := rewrite.LoadOptions("redirects.yml")
-	rewriteEngine, err := rewrite.New(rewriteOptions)
-	if err != nil { // reports any line parse errors.
-		app.Logger().Fatal(err)
-	}
-
 	app.Get("/", index)
 	app.Get("/about", about)
 	app.Get("/docs", docs)
 
-	/*
-		// To use it per-party, even if not route match:
-		app.UseRouter(rewriteEngine.Handler)
-		// To use it per-party when route match:
-		app.Use(rewriteEngine.Handler)
-		//
-		// To use it on a single route just pass it to the Get/Post method.
-		// To make the entire application respect the rewrite rules
-		// you have to wrap the Iris Router and pass the Wrapper method instead,
-		// (recommended way to use this middleware, right before Listen/Run):
-	*/
-	app.WrapRouter(rewriteEngine.Wrapper)
+	app.Subdomain("test").Get("/", testIndex)
 
-	// http://localhost:8080/seo
+	redirects := rewrite.Load("redirects.yml")
+	app.WrapRouter(redirects)
+
+	// http://mydomain.com:8080/seo/about     -> http://www.mydomain.com:8080/about
+	// http://test.mydomain.com:8080
+	// http://localhost:8080/seo              -> http://localhost:8080
 	// http://localhost:8080/about
-	// http://localhost:8080/docs/v12/hello
-	// http://localhost:8080/docs/v12some
-	// http://localhost:8080/oldsome
-	// http://localhost:8080/oldindex/random
+	// http://localhost:8080/docs/v12/hello   -> http://localhost:8080/docs
+	// http://localhost:8080/docs/v12some     -> http://localhost:8080/docs
+	// http://localhost:8080/oldsome          -> http://localhost:8080
+	// http://localhost:8080/oldindex/random  -> http://localhost:8080
 	app.Listen(":8080")
 }
 
@@ -60,3 +38,30 @@ func about(ctx iris.Context) {
 func docs(ctx iris.Context) {
 	ctx.WriteString("Docs")
 }
+
+func testIndex(ctx iris.Context) {
+	ctx.WriteString("Test Subdomain Index")
+}
+
+/* More...
+rewriteOptions := rewrite.Options{
+	RedirectMatch: []string{
+		"301 /seo/(.*) /$1",
+		"301 /docs/v12(.*) /docs",
+		"301 /old(.*) /",
+	},
+	PrimarySubdomain: "www",
+}
+rewriteEngine, err := rewrite.New(rewriteOptions)
+
+// To use it per-party use its `Handler` method. Even if not route match:
+app.UseRouter(rewriteEngine.Handler)
+// To use it per-party when route match:
+app.Use(rewriteEngine.Handler)
+//
+// To use it on a single route just pass it to the Get/Post method.
+//
+// To make the entire application respect the redirect rules
+// you have to wrap the Iris Router and pass the `Rewrite` method instead
+// as we did at this example.
+*/