Include _example program

_example/main.go

@@ -0,0 +1,84 @@
+// cors example
+//
+// ie.
+//
+// Unsuccessful Preflight request:
+// ===============================
+// $ curl -i http://localhost:3000/ -H "Origin: http://no.com" -H "Access-Control-Request-Method: GET" -X OPTIONS
+// HTTP/1.1 200 OK
+// Vary: Origin
+// Vary: Access-Control-Request-Method
+// Vary: Access-Control-Request-Headers
+// Date: Fri, 28 Jul 2017 17:55:47 GMT
+// Content-Length: 0
+// Content-Type: text/plain; charset=utf-8
+//
+//
+// Successful Preflight request:
+// =============================
+// $ curl -i http://localhost:3000/ -H "Origin: http://example.com" -H "Access-Control-Request-Method: GET" -X OPTIONS
+// HTTP/1.1 200 OK
+// Access-Control-Allow-Credentials: true
+// Access-Control-Allow-Methods: GET
+// Access-Control-Allow-Origin: http://example.com
+// Access-Control-Max-Age: 300
+// Vary: Origin
+// Vary: Access-Control-Request-Method
+// Vary: Access-Control-Request-Headers
+// Date: Fri, 28 Jul 2017 17:56:44 GMT
+// Content-Length: 0
+// Content-Type: text/plain; charset=utf-8
+//
+//
+// Content request (after a successful preflight):
+// ===============================================
+// $ curl -i http://localhost:3000/ -H "Origin: http://example.com"
+// HTTP/1.1 200 OK
+// Access-Control-Allow-Credentials: true
+// Access-Control-Allow-Origin: http://example.com
+// Access-Control-Expose-Headers: Link
+// Vary: Origin
+// Date: Fri, 28 Jul 2017 17:57:52 GMT
+// Content-Length: 7
+// Content-Type: text/plain; charset=utf-8
+//
+// welcome%
+//
+package main
+
+import (
+	"net/http"
+
+	"github.com/go-chi/chi"
+	"github.com/go-chi/cors"
+)
+
+func main() {
+	r := chi.NewRouter()
+
+	// Basic CORS
+	// for more ideas, see: https://developer.github.com/v3/#cross-origin-resource-sharing
+	cors := cors.New(cors.Options{
+		AllowOriginFunc:  AllowOriginFunc,
+		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
+		AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
+		ExposedHeaders:   []string{"Link"},
+		AllowCredentials: true,
+		MaxAge:           300, // Maximum value not ignored by any of major browsers
+	})
+	r.Use(cors.Handler)
+
+	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("welcome"))
+	})
+
+	http.ListenAndServe(":3000", r)
+}
+
+func AllowOriginFunc(r *http.Request, origin string) bool {
+	if origin == "http://example.com" {
+		return true
+	}
+
+	return false
+}