martini/return_handler.go at master · feixiangcode/martini · GitHub

43 lines (38 loc) · 1.2 KB

package martini

import (

"github.com/codegangsta/inject"

"net/http"

"reflect"

)

// ReturnHandler is a service that Martini provides that is called

// when a route handler returns something. The ReturnHandler is

// responsible for writing to the ResponseWriter based on the values

// that are passed into this function.

type ReturnHandler func(Context, []reflect.Value)

func defaultReturnHandler() ReturnHandler {

return func(ctx Context, vals []reflect.Value) {

rv := ctx.Get(inject.InterfaceOf((*http.ResponseWriter)(nil)))

res := rv.Interface().(http.ResponseWriter)

var responseVal reflect.Value

if len(vals) > 1 && vals[0].Kind() == reflect.Int {

res.WriteHeader(int(vals[0].Int()))

responseVal = vals[1]

} else if len(vals) > 0 {

responseVal = vals[0]

}

if canDeref(responseVal) {

responseVal = responseVal.Elem()

}

if isByteSlice(responseVal) {

res.Write(responseVal.Bytes())

} else {

res.Write([]byte(responseVal.String()))

}

func isByteSlice(val reflect.Value) bool {

return val.Kind() == reflect.Slice && val.Type().Elem().Kind() == reflect.Uint8

}

func canDeref(val reflect.Value) bool {

return val.Kind() == reflect.Interface || val.Kind() == reflect.Ptr

}

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