Gorilla Mux Regex for number between range and predefined options

Question

My route looks like this

max := viper.GetInt("channels")

lights_router.Path("/{channel}/{action}").
    Methods("OPTIONS","GET").
    Handler( util.Adapt(SerialHandler(router), util.EnableCORS()))

Channels have to be between 1 and max and action has to be either false or true.

Answer 1

func ValidetaChannel() Adapter {
    return func(h http.Handler) http.Handler {
        return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            channel, err := strconv.Atoi(mux.Vars(r)["channel"])
            if err != nil {
                http.Error(w, http.StatusText(400), 400)
                return
            }
            if channel >= 1 && channel <= viper.GetInt("channels") {
                h.ServeHTTP(w, r)
                return
            }
            http.Error(w, http.StatusText(400), 400)

        })
    }
}


func ValidetaAction() Adapter {
    return func(h http.Handler) http.Handler {
        return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            if mux.Vars(r)["action"] == "true" || mux.Vars(r)["action"] == "false" {
                h.ServeHTTP(w, r)
                return
            }
            http.Error(w, http.StatusText(400), 400)
        })
    }
}

Answer 2

filter by Route

"/{channel:(?:[0-9]{1,3})}/{action:(?:true|false)}/"

Example

package main

import (
    "github.com/gorilla/mux"
    "log"
    "net/http"
    "regexp"
    "strconv"
)

var myRegex *regexp.Regexp

func main() {
    mux := mux.NewRouter()
    myRegex = regexp.MustCompile(`/(?P<channel>[0-9]{1,3})/(?P<action>(true|false))/`)
    maxChannel := 100
    mux.Path("/{channel:(?:[0-9]{1,3})}/{action:(?:true|false)}/").
        HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            matchs := myRegex.FindStringSubmatch(r.URL.Path) // [all, channel, action]
            /* https://stackoverflow.com/a/20751656/9935654
            dict := make(map[string]string)
            for i, name := range myRegex.SubexpNames() {
                if i != 0 && name != "" {
                    dict[name] = matchs[i]
                }
            }
            channelStr := dict["channel"]
            */

            channelStr := matchs[1]
            curChannel, _ := strconv.Atoi(channelStr)
            if channelStr[:1] == "0" || curChannel > maxChannel {
                log.Println("error")
                return
            }
            log.Println("ok")
        })
    server := http.Server{Addr:":1234", Handler: mux}
    server.ListenAndServe()
}