// Copyright 2014 Manu Martinez-Almeida.  All rights reserved.
  // Use of this source code is governed by a MIT style
  // license that can be found in the LICENSE file.
  
  package render
  
  import "net/http"
  
  // Render interface is to be implemented by JSON, XML, HTML, YAML and so on.
  type Render interface {
  	// Render writes data with custom ContentType.
  	Render(http.ResponseWriter) error
  	// WriteContentType writes custom ContentType.
  	WriteContentType(w http.ResponseWriter)
  }
  
  var (
  	_ Render     = JSON{}
  	_ Render     = IndentedJSON{}
  	_ Render     = SecureJSON{}
  	_ Render     = JsonpJSON{}
  	_ Render     = XML{}
  	_ Render     = String{}
  	_ Render     = Redirect{}
  	_ Render     = Data{}
  	_ Render     = HTML{}
  	_ HTMLRender = HTMLDebug{}
  	_ HTMLRender = HTMLProduction{}
  	_ Render     = YAML{}
  	_ Render     = MsgPack{}
  	_ Render     = Reader{}
  	_ Render     = AsciiJSON{}
  	_ Render     = ProtoBuf{}
  )
  
  func writeContentType(w http.ResponseWriter, value []string) {
  	header := w.Header()
  	if val := header["Content-Type"]; len(val) == 0 {
  		header["Content-Type"] = value
  	}
  }