initial commit

vendor/github.com/ant0ine/go-json-rest/rest/middleware.go

@@ -0,0 +1,72 @@
+package rest
+
+import (
+	"net/http"
+)
+
+// HandlerFunc defines the handler function. It is the go-json-rest equivalent of http.HandlerFunc.
+type HandlerFunc func(ResponseWriter, *Request)
+
+// App defines the interface that an object should implement to be used as an app in this framework
+// stack. The App is the top element of the stack, the other elements being middlewares.
+type App interface {
+	AppFunc() HandlerFunc
+}
+
+// AppSimple is an adapter type that makes it easy to write an App with a simple function.
+// eg: rest.NewApi(rest.AppSimple(func(w rest.ResponseWriter, r *rest.Request) { ... }))
+type AppSimple HandlerFunc
+
+// AppFunc makes AppSimple implement the App interface.
+func (as AppSimple) AppFunc() HandlerFunc {
+	return HandlerFunc(as)
+}
+
+// Middleware defines the interface that objects must implement in order to wrap a HandlerFunc and
+// be used in the middleware stack.
+type Middleware interface {
+	MiddlewareFunc(handler HandlerFunc) HandlerFunc
+}
+
+// MiddlewareSimple is an adapter type that makes it easy to write a Middleware with a simple
+// function. eg: api.Use(rest.MiddlewareSimple(func(h HandlerFunc) Handlerfunc { ... }))
+type MiddlewareSimple func(handler HandlerFunc) HandlerFunc
+
+// MiddlewareFunc makes MiddlewareSimple implement the Middleware interface.
+func (ms MiddlewareSimple) MiddlewareFunc(handler HandlerFunc) HandlerFunc {
+	return ms(handler)
+}
+
+// WrapMiddlewares calls the MiddlewareFunc methods in the reverse order and returns an HandlerFunc
+// ready to be executed. This can be used to wrap a set of middlewares, post routing, on a per Route
+// basis.
+func WrapMiddlewares(middlewares []Middleware, handler HandlerFunc) HandlerFunc {
+	wrapped := handler
+	for i := len(middlewares) - 1; i >= 0; i-- {
+		wrapped = middlewares[i].MiddlewareFunc(wrapped)
+	}
+	return wrapped
+}
+
+// Handle the transition between net/http and go-json-rest objects.
+// It intanciates the rest.Request and rest.ResponseWriter, ...
+func adapterFunc(handler HandlerFunc) http.HandlerFunc {
+
+	return func(origWriter http.ResponseWriter, origRequest *http.Request) {
+
+		// instantiate the rest objects
+		request := &Request{
+			origRequest,
+			nil,
+			map[string]interface{}{},
+		}
+
+		writer := &responseWriter{
+			origWriter,
+			false,
+		}
+
+		// call the wrapped handler
+		handler(writer, request)
+	}
+}