【Gin-v1.9.0源码阅读】render/render.go

// 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.
// Render接口将通过JSON、XML、HTML、YAML等实现。
type Render interface {
	// Render writes data with custom ContentType.
	// Render使用自定义ContentType写入数据。
	Render(http.ResponseWriter) error
	// WriteContentType writes custom ContentType.
	// WriteContentType写入自定义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     = Reader{}
	_ Render     = AsciiJSON{}
	_ Render     = ProtoBuf{}
	_ Render     = TOML{}
)

func writeContentType(w http.ResponseWriter, value []string) {
	header := w.Header()
	if val := header["Content-Type"]; len(val) == 0 {
		header["Content-Type"] = value
	}
}