[Golang] Một số ví dụ lập trình Fiber Web Framework

Ở bài viết trước: Giới thiệu về Fiber Web Framework. Sau đây là 1 số ví dụ sử dụng Fiber Web Framework. Nó sẽ giúp các bạn có cái nhìn tổng quan về Fiber Web Framework.

Chương trình Hello World cơ bản

package main

import "github.com/gofiber/fiber/v2"

func main() {
    app := fiber.New()

    app.Get("/", func(c *fiber.Ctx) error {
        return c.SendString("Hello, World ?!")
    })

    app.Listen(":3000")
}

Basic Routing / Định tuyến cơ bản

func main() {
    app := fiber.New()

    // GET /john
    app.Get("/:name", func(c *fiber.Ctx) error {
        msg := fmt.Sprintf("Hello, %s ?!", c.Params("name"))
        return c.SendString(msg) // => Hello john ?!
    })

    // GET /john/75
    app.Get("/:name/:age/:gender?", func(c *fiber.Ctx) error {
        msg := fmt.Sprintf("? %s is %s years old", c.Params("name"), c.Params("age"))
        return c.SendString(msg) // => ? john is 75 years old
    })

    // GET /dictionary.txt
    app.Get("/:file.:ext", func(c *fiber.Ctx) error {
        msg := fmt.Sprintf("? %s.%s", c.Params("file"), c.Params("ext"))
        return c.SendString(msg) // => ? dictionary.txt
    })

    // GET /flights/LAX-SFO
    app.Get("/flights/:from-:to", func(c *fiber.Ctx) error {
        msg := fmt.Sprintf("? From: %s, To: %s", c.Params("from"), c.Params("to"))
        return c.SendString(msg) // => ? From: LAX, To: SFO
    })

    // GET /api/register
    app.Get("/api/*", func(c *fiber.Ctx) error {
        msg := fmt.Sprintf("✋ %s", c.Params("*"))
        return c.SendString(msg) // => ✋ register
    })

    log.Fatal(app.Listen(":3000"))
}

Serving Static Files / Xử lý file tĩnh

func main() {
    app := fiber.New()

    app.Static("/", "./public")
    // => http://localhost:3000/js/script.js
    // => http://localhost:3000/css/style.css

    app.Static("/prefix", "./public")
    // => http://localhost:3000/prefix/js/script.js
    // => http://localhost:3000/prefix/css/style.css

    app.Static("*", "./public/index.html")
    // => http://localhost:3000/any/path/shows/index/html

    log.Fatal(app.Listen(":3000"))
}

Middleware & Next

func main() {
    app := fiber.New()

    // Match any route
    app.Use(func(c *fiber.Ctx) error {
        fmt.Println("? First handler")
        return c.Next()
    })

    // Match all routes starting with /api
    app.Use("/api", func(c *fiber.Ctx) error {
        fmt.Println("? Second handler")
        return c.Next()
    })

    // GET /api/register
    app.Get("/api/list", func(c *fiber.Ctx) error {
        fmt.Println("? Last handler")
        return c.SendString("Hello, World ?!")
    })

    log.Fatal(app.Listen(":3000"))
}

Views Template Engines

package main

import (
    "github.com/gofiber/fiber/v2"
    "github.com/gofiber/template/pug"
)

func main() {
    // You can setup Views engine before initiation app:
    app := fiber.New(fiber.Config{
        Views: pug.New("./views", ".pug"),
    })

    // And now, you can call template `./views/home.pug` like this:
    app.Get("/", func(c *fiber.Ctx) error {
        return c.Render("home", fiber.Map{
            "title": "Homepage",
            "year":  1999,
        })
    })

    log.Fatal(app.Listen(":3000"))
}

Grouping routes into chains / Nhóm các định tuyển trong chuỗi

func middleware(c *fiber.Ctx) error {
    fmt.Println("Don't mind me!")
    return c.Next()
}

func handler(c *fiber.Ctx) error {
    return c.SendString(c.Path())
}

func main() {
    app := fiber.New()

    // Root API route
    api := app.Group("/api", middleware) // /api

    // API v1 routes
    v1 := api.Group("/v1", middleware) // /api/v1
    v1.Get("/list", handler)           // /api/v1/list
    v1.Get("/user", handler)           // /api/v1/user

    // API v2 routes
    v2 := api.Group("/v2", middleware) // /api/v2
    v2.Get("/list", handler)           // /api/v2/list
    v2.Get("/user", handler)           // /api/v2/user

    // ...
}

Middleware logger

package main

import (
    "log"

    "github.com/gofiber/fiber/v2"
    "github.com/gofiber/fiber/v2/middleware/logger"
)

func main() {
    app := fiber.New()

    app.Use(logger.New())

    // ...

    log.Fatal(app.Listen(":3000"))
}

Cross-Origin Resource Sharing (CORS)

import (
    "log"

    "github.com/gofiber/fiber/v2"
    "github.com/gofiber/fiber/v2/middleware/cors"
)

func main() {
    app := fiber.New()

    app.Use(cors.New())

    // ...

    log.Fatal(app.Listen(":3000"))
}

Custom 404 response / Tạo phản hồi 404

func main() {
    app := fiber.New()

    app.Static("/", "./public")

    app.Get("/demo", func(c *fiber.Ctx) error {
        return c.SendString("This is a demo!")
    })

    app.Post("/register", func(c *fiber.Ctx) error {
        return c.SendString("Welcome!")
    })

    // Last middleware to match anything
    app.Use(func(c *fiber.Ctx) error {
        return c.SendStatus(404)
        // => 404 "Not Found"
    })

    log.Fatal(app.Listen(":3000"))
}

JSON Response / Phản hồi JSON

type User struct {
    Name string `json:"name"`
    Age  int    `json:"age"`
}

func main() {
    app := fiber.New()

    app.Get("/user", func(c *fiber.Ctx) error {
        return c.JSON(&User{"John", 20})
        // => {"name":"John", "age":20}
    })

    app.Get("/json", func(c *fiber.Ctx) error {
        return c.JSON(fiber.Map{
            "success": true,
            "message": "Hi John!",
        })
        // => {"success":true, "message":"Hi John!"}
    })

    log.Fatal(app.Listen(":3000"))
}

WebSocket Upgrade / Nâng cấp WebSocket

import (
    "github.com/gofiber/fiber/v2"
    "github.com/gofiber/fiber/v2/middleware/websocket"
)

func main() {
  app := fiber.New()

  app.Get("/ws", websocket.New(func(c *websocket.Conn) {
    for {
      mt, msg, err := c.ReadMessage()
      if err != nil {
        log.Println("read:", err)
        break
      }
      log.Printf("recv: %s", msg)
      err = c.WriteMessage(mt, msg)
      if err != nil {
        log.Println("write:", err)
        break
      }
    }
  }))

  log.Fatal(app.Listen(":3000"))
  // ws://localhost:3000/ws
}

Recover middleware / Khôi phục Middleware

import (
    "github.com/gofiber/fiber/v2"
    "github.com/gofiber/fiber/v2/middleware/recover"
)

func main() {
    app := fiber.New()

    app.Use(recover.New())

    app.Get("/", func(c *fiber.Ctx) error {
        panic("normally this would crash your app")
    })

    log.Fatal(app.Listen(":3000"))
}

Validator package

type Job struct{
    Type          string `validate:"required,min=3,max=32"`
    Salary        int    `validate:"required,number"`
}

type User struct{
    Name          string  `validate:"required,min=3,max=32"`
    IsActive      bool    `validate:"required,eq=True|eq=False"`
    Email         string  `validate:"required,email,min=6,max=32"`
    Job           Job     `validate:"dive"`
}

type ErrorResponse struct {
    FailedField string
    Tag         string
    Value       string
}

func ValidateStruct(user User) []*ErrorResponse {
    var errors []*ErrorResponse
    validate := validator.New()
    err := validate.Struct(user)
    if err != nil {
        for _, err := range err.(validator.ValidationErrors) {
            var element ErrorResponse
            element.FailedField = err.StructNamespace()
            element.Tag = err.Tag()
            element.Value = err.Param()
            errors = append(errors, &element)
        }
    }
    return errors
}

func AddUser(c *fiber.Ctx) {
    //Connect to database
    user := new(User)
    if err := c.BodyParser(user); err != nil {
        errors := ValidateStruct(*user)
    if errors != nil {
        c.JSON(errors)
        return
    }
    }
    //Do something else here

  //Return user
    c.JSON(user)
}

// Running a test with the following curl commands

// curl -X POST -H "Content-Type: application/json" --data "{\"name\":\"john\",\"isactive\":\"True\"}" http://localhost:8080/register/user

// Results in 

// [{"FailedField":"User.Email","Tag":"required","Value":""},{"FailedField":"User.Job.Salary","Tag":"required","Value":""},{"FailedField":"User.Job.Type","Tag":"required","Value":""}]⏎

Catching Errors / Bắt lỗi

app.Get("/", func(c *fiber.Ctx) error {
    // Pass error to Fiber
    return c.SendFile("file-does-not-exist")
})

Các bạn có tham khảo nhiều ví dụ, ứng dụng của Fiber Web Framework ở đây

Nguồn: vinasupport.com