mirror of
https://github.com/vbatts/imgsrv.git
synced 2024-12-27 00:06:29 +00:00
73 lines
2.4 KiB
Go
73 lines
2.4 KiB
Go
|
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 sets the Access-Control-Allow-Methods response header
|
||
|
|
// on a request, by matching routes based only on paths. It also handles
|
||
|
|
// OPTIONS requests, by settings Access-Control-Allow-Methods, and then
|
||
|
|
// returning without calling the next http handler.
|
||
|
|
func CORSMethodMiddleware(r *Router) MiddlewareFunc {
|
||
|
|
return func(next http.Handler) http.Handler {
|
||
|
|
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
|
||
|
|
var allMethods []string
|
||
|
|
|
||
|
|
err := r.Walk(func(route *Route, _ *Router, _ []*Route) error {
|
||
|
|
for _, m := range route.matchers {
|
||
|
|
if _, ok := m.(*routeRegexp); ok {
|
||
|
|
if m.Match(req, &RouteMatch{}) {
|
||
|
|
methods, err := route.GetMethods()
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
|
||
|
|
allMethods = append(allMethods, methods...)
|
||
|
|
}
|
||
|
|
break
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return nil
|
||
|
|
})
|
||
|
|
|
||
|
|
if err == nil {
|
||
|
|
w.Header().Set("Access-Control-Allow-Methods", strings.Join(append(allMethods, "OPTIONS"), ","))
|
||
|
|
|
||
|
|
if req.Method == "OPTIONS" {
|
||
|
|
return
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
next.ServeHTTP(w, req)
|
||
|
|
})
|
||
|
|
}
|
||
|
|
}
|