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// Copyright 2015 Matthew Holt and The Caddy 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 markdown
import (
"bytes"
"net/http"
"strconv"
"strings"
"sync"
"github.com/russross/blackfriday/v2"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
)
func init() {
caddy.RegisterModule(caddy.Module{
Name: "http.handlers.markdown",
New: func() interface{} { return new(Markdown) },
})
}
// Markdown is a middleware for rendering a Markdown response body.
type Markdown struct {
}
func (m Markdown) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
buf := bufPool.Get().(*bytes.Buffer)
buf.Reset()
defer bufPool.Put(buf)
shouldBuf := func(status int) bool {
return strings.HasPrefix(w.Header().Get("Content-Type"), "text/")
}
rec := caddyhttp.NewResponseRecorder(w, buf, shouldBuf)
err := next.ServeHTTP(rec, r)
if err != nil {
return err
}
if !rec.Buffered() {
return nil
}
output := blackfriday.Run(buf.Bytes())
w.Header().Set("Content-Length", strconv.Itoa(len(output)))
w.Header().Set("Content-Type", "text/html; charset=utf-8")
w.Header().Del("Accept-Ranges") // we don't know ranges for dynamically-created content
w.Header().Del("Etag") // don't know a way to quickly generate etag for dynamic content
w.Header().Del("Last-Modified") // useless for dynamic content since it's always changing
w.WriteHeader(rec.Status())
w.Write(output)
return nil
}
var bufPool = sync.Pool{
New: func() interface{} {
return new(bytes.Buffer)
},
}
// Interface guard
var _ caddyhttp.MiddlewareHandler = (*Markdown)(nil)
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