Gin

A Web Framework in Go. (https://godoc.org/github.com/gin-gonic/gin)

Overview

package main

import "github.com/gin-gonic/gin"

func pong(c *gin.Context) {
    // JSON(): serialize and send return code and object to JSON.
    // H: short for map[string]interface{}
    c.JSON(200, gin.H{
        "message": "pong",
    })
}

func main() {
    r := gin.Default()
    r.GET("/ping", pong) // "/ping" is routed to pong()
    r.Run() // listen and serve on 0.0.0.0:8080
}

Route

• GET

  // with URL parameters
  fetch('/api?action=getcomment'+'&pid='+pid).then(...)
  

  r.GET("/api", apiGet)
  
  func apiGet(c *gin.Context) {
    action := c.Query("action")
    switch action {
    case "getcomment":
        getOne(c)
        return
    case "search":
        searchPost(c)
        return
    default:
        c.AbortWithStatus(403)
    }
  }
  
  func searchPost(c *gin.Context) {
    page, err := strconv.Atoi(c.Query("page"))
    pageSize, err := strconv.Atoi(c.Query("pagesize"))
    keywords := c.Query("keywords")
  
    data, err2 := dbSearchSavedPosts(strings.ReplaceAll(keywords, " ", " +"), (page-1)*pageSize, pageSize)
    if err2 != nil {
        log.Printf("dbSearchSavedPosts failed while searchList: %s\n", err2)
        httpReturnWithCodeOne(c, "数据库读取失败，请联系管理员")
        return
    } else {
        c.JSON(http.StatusOK, gin.H{
            "code":      0,
            "data":      IfThenElse(data != nil, data, []string{}),
            "timestamp": getTimeStamp(),
            "count":     IfThenElse(data != nil, len(data), 0),
        })
        return
    }
  }
  

• POST

  • URL parameters

    fetch(
        'api/login'
        +'?user='+encodeURIComponent(this.username_ref.current.value)
        +'&valid_code='+encodeURIComponent(this.password_ref.current.value), 
        {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({
                excluded_scopes: this.state.excluded_scopes||[],
            }),
        }
    ).then(...)
    

    Use c.Query.

    r.POST('/api/login', login)
    
    func login(c *gin.Context) {
        user := c.Query("user")
        code := c.Query("valid_code")
    
        hashedUser := hashEmail(user)
        token := genToken()
    
        err = dbSaveToken(token, hashedUser)
        if err != nil {
            c.JSON(http.StatusOK, gin.H{
                "code": 1,
                "msg": "数据库写入失败，请联系管理员",
            })
            return
        } else {
            c.JSON(http.StatusOK, gin.H{
                "code": 0,
                "msg": "登录成功！",
                "user_token": token,
            })
            return
        }
    }
    

  • Form

    Use c.PostForm.

    r := gin.Default()
    r.POST("/", func(c *gin.Context) {
        wechat := c.PostForm("wechat")
        c.String(200, wechat)
    })
    

CORS

package main

import (
    "time"

    "github.com/gin-contrib/cors"
    "github.com/gin-gonic/gin"
)

func main() {
    router := gin.Default()
    // CORS for https://foo.com and https://github.com origins, allowing:
    // - PUT and PATCH methods
    // - Origin header
    // - Credentials share
    // - Preflight requests cached for 12 hours
    router.Use(cors.New(cors.Config{
        AllowOrigins:     []string{"https://foo.com"},
        AllowMethods:     []string{"PUT", "PATCH"},
        AllowHeaders:     []string{"Origin"},
        ExposeHeaders:    []string{"Content-Length"},
        AllowCredentials: true,
        AllowOriginFunc: func(origin string) bool {
            return origin == "https://github.com"
        },
        MaxAge: 12 * time.Hour,
    }))
    router.Run()
}