1 files changed, 74 insertions, 0 deletions
diff --git a/vendor/github.com/gorilla/mux/middleware.go b/vendor/github.com/gorilla/mux/middleware.go
new file mode 100644
index 00000000..cb51c565
--- /dev/null
+++ b/vendor/github.com/gorilla/mux/middleware.go
@@ -0,0 +1,74 @@
+package mux
+
+import (
+	"net/http"
+	"strings"
+)
+
+// MiddlewareFunc is a function which receives an http.Handler and returns another http.Handler.
+// Typically, the returned handler is a closure which does something with the http.ResponseWriter and http.Request passed
+// to it, and then calls the handler passed as parameter to the MiddlewareFunc.
+type MiddlewareFunc func(http.Handler) http.Handler
+
+// middleware interface is anything which implements a MiddlewareFunc named Middleware.
+type middleware interface {
+	Middleware(handler http.Handler) http.Handler
+}
+
+// Middleware allows MiddlewareFunc to implement the middleware interface.
+func (mw MiddlewareFunc) Middleware(handler http.Handler) http.Handler {
+	return mw(handler)
+}
+
+// Use appends a MiddlewareFunc to the chain. Middleware can be used to intercept or otherwise modify requests and/or responses, and are executed in the order that they are applied to the Router.
+func (r *Router) Use(mwf ...MiddlewareFunc) {
+	for _, fn := range mwf {
+		r.middlewares = append(r.middlewares, fn)
+	}
+}
+
+// useInterface appends a middleware to the chain. Middleware can be used to intercept or otherwise modify requests and/or responses, and are executed in the order that they are applied to the Router.
+func (r *Router) useInterface(mw middleware) {
+	r.middlewares = append(r.middlewares, mw)
+}
+
+// CORSMethodMiddleware automatically sets the Access-Control-Allow-Methods response header
+// on requests for routes that have an OPTIONS method matcher to all the method matchers on
+// the route. Routes that do not explicitly handle OPTIONS requests will not be processed
+// by the middleware. See examples for usage.
+func CORSMethodMiddleware(r *Router) MiddlewareFunc {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+			allMethods, err := getAllMethodsForRoute(r, req)
+			if err == nil {
+				for _, v := range allMethods {
+					if v == http.MethodOptions {
+						w.Header().Set("Access-Control-Allow-Methods", strings.Join(allMethods, ","))
+					}
+				}
+			}
+
+			next.ServeHTTP(w, req)
+		})
+	}
+}
+
+// getAllMethodsForRoute returns all the methods from method matchers matching a given
+// request.
+func getAllMethodsForRoute(r *Router, req *http.Request) ([]string, error) {
+	var allMethods []string
+
+	for _, route := range r.routes {
+		var match RouteMatch
+		if route.Match(req, &match) || match.MatchErr == ErrMethodMismatch {
+			methods, err := route.GetMethods()
+			if err != nil {
+				return nil, err
+			}
+
+			allMethods = append(allMethods, methods...)
+		}
+	}
+
+	return allMethods, nil
+}