Go语言Gin-3渲染

4.gin 渲染

4.1各种数据格式响应

package main

import (
	"github.com/gin-gonic/gin"
	"github.com/gin-gonic/gin/testdata/protoexample"
)

func main() {
	r := gin.Default()
	// 1. json
	r.GET("someJSON", func(c *gin.Context) {
		c.JSON(200, gin.H{"message": "someJSON","status":200})
	})
	// 2.结构体响应
	r.GET("/someStruct", func(c *gin.Context) {
		var msg struct {
			Name string
			Message string
			Number int
		}
		msg.Name = "root"
		msg.Message = "message"
		msg.Number = 123
		c.JSON(200,msg)
	})
	// 3. XML
	r.GET("/someXML", func(c *gin.Context) {
		c.XML(200, gin.H{"message":"abcc"})
	})
	// 4.YAML响应
	r.GET("/someYAML", func(c *gin.Context) {
		c.YAML(200, gin.H{"name":"zhangsan"})
	})
	// 5.protobuf 谷歌开发搞笑存储读取工具
	r.GET("/someProtoBuf", func(c *gin.Context) {
		reps := []int64{int64(1), int64(2)}
		// 定义数据
		label := "label"
		data := &protoexample.Test{
			Label: &label,
			Reps: reps,
		}
		c.ProtoBuf(200,data)
	})
	r.Run(":8000")
}

4.2 HTML模版渲染

gin 支持加载HTML模版，然后根据模版参数进行配置并返回相应的数据，本质上就是字符串替换。
LoadHTMLGlob()方法可以加载模版文件

目录结构：

gin_demo
	|__app
	|		|__main.go
	|__tem
			|__index.html

main.go

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.LoadHTMLGlob("tem/*")
	r.GET("/index", func(c *gin.Context) {
		c.HTML(http.StatusOK,"index.html", gin.H{"title":"I am test", "ce": "123456"})
	})
	r.Run()
}

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div>
        {{.ce}}
    </div>
</body>
</html>

gin_demo
	|__app
	|   |__main.go
	|__tem
			|__public
			| 		|__footer.html
			| 		|__header.html
			|___user
						|__index.html

app/main.go

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.LoadHTMLGlob("tem/**/*")
	r.GET("/index", func(c *gin.Context) {
		c.HTML(http.StatusOK,"user/index.html", gin.H{"title":"I am test","name":"ming"})
	})
	r.Run()
}

user/index.html

{{ define "user/index.html"}}
{{ template "public/header" .}}
    {{.name}}
{{template "public/footer" .}}
{{ end }}

public/footer.html

{{define "public/footer"}}
    </body>
    </html>
{{ end }}

public/header.html

{{define "public/header"}}
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="ie=edge">
        <title>{{.title}}</title>
    </head>
    <body>

{{end}}

如果想引入静态文件需要定义一个静态文件目录

r.Static("/asserts","./asserts")

4.3重定向

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.GET("/index", func(c *gin.Context) {
		c.Redirect(http.StatusMovedPermanently, "/demo")
	})
	r.GET("/demo", func(c *gin.Context) {
		c.JSON(200, gin.H{"message": "someJSON", "status": 200})
	})
	r.Run()
}

4.4 同步异步

groutine 机制可以方便实现异步处理
另外，在启动新的goroutine时，不应该使用原始上下文，必须使用它的只读副本。

package main

import (
	"github.com/gin-gonic/gin"
	"log"
	"time"
)

func main() {
	// 1创建路由
	r := gin.Default()
	r.GET("/long_async", func(c *gin.Context) {
		// 拷贝上下文
		copyContext := c.Copy()
		// 异步执行 直接返回
		go func() {
			time.Sleep(3 * time.Second)
			log.Println("异步执行：" + copyContext.Request.URL.Path)
		}()
	})
	// 2. 同步执行：需要等待3秒才有返回
	r.GET("/long_sync", func(c *gin.Context) {
		time.Sleep(3 * time.Second)
		log.Println("同步执行：" + c.Request.URL.Path)
	})
	r.Run(":8000")
}