Golang

decorate.go

type APIHandler func(http.ResponseWriter, req *http.Request, ps httprouter.Params)
type Decorator func(APIHandler) APIHandler

func Log(logf lg.AppLogFunc) Decorator{
    return func(f APIHandler) APIHandler{
        return func(w http.ResponseWriter, req *http.Request, ps httprouter.Parms){
            start = time.Now()
            response, err = f(w, req, ps)
            elapsed = time.Since(Start)
            status := 200
            # ...
            logf(lg.INFO, "%d %s %s (%s) %s",
				status, req.Method, req.URL.RequestURI(), req.RemoteAddr, elapsed)
        }
    }
}

func Decorate(f APIHandler, ds ...Decorator) httprouter.Handler{
    decorated := f
    for _, decorate := range ds {
        decoreated = decorate(decorated)
    }
    return func(w http.ResponseWriter, req *http.Request, ps httprouter.Params){
        decoreated(w, req, ps)
    }
}