grafana/pkg/macaron/return_handler.go
Serge Zaitsev 9b2d7d6d69
Gradually remove Macaron web framework (#36325)
* add macaron code to the code base

* remove unused secure cookies support from macaron

* clean up modules

* remove com dependency

* fix silly typos

* little cleanup, remove recovery middleware

* remove logger middleware

* remove static handler and remove unused context methods

* bring inject into macaron codebase

* remove unused applicator

* add back macaron license

* more cleanups in macaron code

* remove unused injector Set method

* remove unused context methods: param to int conversion, body helper type, cookie helpers

* remove action from context

* remove complex environment handling, we only use Env variable

* restore ReplaceAllParams to fix the tests
2021-07-08 14:19:40 +02:00

75 lines
2.1 KiB
Go

// Copyright 2013 Martini Authors
// Copyright 2014 The Macaron Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"): you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.
package macaron
import (
"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 canDeref(val reflect.Value) bool {
return val.Kind() == reflect.Interface || val.Kind() == reflect.Ptr
}
func isError(val reflect.Value) bool {
_, ok := val.Interface().(error)
return ok
}
func isByteSlice(val reflect.Value) bool {
return val.Kind() == reflect.Slice && val.Type().Elem().Kind() == reflect.Uint8
}
func defaultReturnHandler() ReturnHandler {
return func(ctx *Context, vals []reflect.Value) {
rv := ctx.GetVal(InterfaceOf((*http.ResponseWriter)(nil)))
resp := rv.Interface().(http.ResponseWriter)
var respVal reflect.Value
if len(vals) > 1 && vals[0].Kind() == reflect.Int {
resp.WriteHeader(int(vals[0].Int()))
respVal = vals[1]
} else if len(vals) > 0 {
respVal = vals[0]
if isError(respVal) {
err := respVal.Interface().(error)
if err != nil {
ctx.internalServerError(ctx, err)
}
return
} else if canDeref(respVal) {
if respVal.IsNil() {
return // Ignore nil error
}
}
}
if canDeref(respVal) {
respVal = respVal.Elem()
}
if isByteSlice(respVal) {
_, _ = resp.Write(respVal.Bytes())
} else {
_, _ = resp.Write([]byte(respVal.String()))
}
}
}