/
cors.go
60 lines (50 loc) · 1.69 KB
/
cors.go
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// Copyright 2020 Asim Aslam
//
// 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
//
// https://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.
//
// Original source: github.com/micro/go-micro/v3/api/server/cors/cors.go
package http
import (
"net/http"
)
// CombinedCORSHandler wraps a server and provides CORS headers
func CombinedCORSHandler(h http.Handler) http.Handler {
return corsHandler{h}
}
type corsHandler struct {
handler http.Handler
}
func (c corsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
SetHeaders(w, r)
if r.Method == "OPTIONS" {
return
}
c.handler.ServeHTTP(w, r)
}
// SetHeaders sets the CORS headers
func SetHeaders(w http.ResponseWriter, r *http.Request) {
set := func(w http.ResponseWriter, k, v string) {
if v := w.Header().Get(k); len(v) > 0 {
return
}
w.Header().Set(k, v)
}
if origin := r.Header.Get("Origin"); len(origin) > 0 {
set(w, "Access-Control-Allow-Origin", origin)
} else {
set(w, "Access-Control-Allow-Origin", "*")
}
set(w, "Access-Control-Allow-Credentials", "true")
set(w, "Access-Control-Allow-Methods", "POST, PATCH, GET, OPTIONS, PUT, DELETE")
set(w, "Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, Micro-Namespace")
}