package
0.0.0-20220301134809-f78f1b81283a
Repository: https://github.com/oneleo/golang-cht.git
Documentation: pkg.go.dev
# README
參考
安裝
- git for windows
- golang
- go get -u github.com/gin-gonic/gin
Step 1：建置論壇骨架
新建「功能表」模板：./templates/menu.html
<!--menu.html-->
<nav class="navbar navbar-default">
<div class="container">
<div class="navbar-header">
<a class="navbar-brand" href="/">
Home
</a>
</div>
</div>
</nav>
新建「標頭」模板：./templates/header.html
<!--header.html-->
<!doctype html>
<html>
<head>
<!--Use the title variable to set the title of the page-->
<title>{{ .title }}</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta charset="UTF-8">
<!--Use bootstrap to make the application look nice-->
<!--An overview of Bootstrap: https://bootstrapdocs.com/v3.3.6/docs/getting-started/-->
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css"
integrity="sha384-1q8mTJOASx8j1Au+a5WDVnPi2lkFfwwEAa8hDDdjZlpLegxhjVME1fgjWPGmkzs7" crossorigin="anonymous">
<!-- Optional theme -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap-theme.min.css"
integrity="sha384-fLW2N01lMqjakBkx3l/M9EahuwpSfeNvV63J5ezn3uZzapT0u7EYsXMjQV+0En5r" crossorigin="anonymous">
<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"
integrity="sha384-0mSbJDEHialfmuBBQP6A4Qrprq5OVfW37PRR3j5ELqxss1yVqOtnepnHVP9aJ7xS"
crossorigin="anonymous"></script>
</head>
<body class="container">
<!--Embed the menu.html template at this location-->
{{ template "menu.html" . }}
新建「頁尾」模板：./templates/footer.html
<!--footer.html-->
</body>
</html>
新建「首頁」模板：./templates/index.html
<!--index.html-->
<!--Embed the header.html template at this location-->
{{ template "header.html" .}}
<h1>Hello Gin!</h1>
<!--Embed the footer.html template at this location-->
{{ template "footer.html" .}}
新建 Go 程式碼：./main.go
package main
import (
"net/http"
"github.com/gin-gonic/gin"
)
var router *gin.Engine
func main() {
// Set the router as the default one provided by Gin
router = gin.Default()
// Process the templates at the start so that they don't have to be loaded
// from the disk again. This makes serving HTML pages very fast.
router.LoadHTMLGlob("templates/*")
// Define the route for the index page and display the index.html template
// To start with, we'll use an inline route handler. Later on, we'll create
// standalone functions that will be used as route handlers.
router.GET("/", func(c *gin.Context) {
// Call the HTML method of the Context to render a template
c.HTML(
// Set the HTTP status to 200 (OK)
http.StatusOK,
// Use the index.html template
"index.html",
// Pass the data that the page uses (in this case, 'title')
gin.H{
"title": "Home Page",
},
)
})
// Start serving the application
router.Run()
}
測試
> go build -o app.exe
> ./app.exe
- 至 localhost:8080 查看
Step 2：建置可瀏覽預設文章的論壇
新建 Go 程式碼：./routes.go
// routes.go
package main
func initializeRoutes() {
// Handle the index route
router.GET("/", showIndexPage)
}
【修改】 Go 程式碼：./main.go
package main
import (
"github.com/gin-gonic/gin"
)
var router *gin.Engine
func main() {
// Set the router as the default one provided by Gin
router = gin.Default()
// Process the templates at the start so that they don't have to be loaded
// from the disk again. This makes serving HTML pages very fast.
router.LoadHTMLGlob("templates/*")
// Initialize the routes
initializeRoutes()
// Start serving the application
router.Run()
}
新建 Go 程式碼：./models.article.go
// models.article.go
package main
type article struct {
ID int `json:"id"`
Title string `json:"title"`
Content string `json:"content"`
}
// For this demo, we're storing the article list in memory
// In a real application, this list will most likely be fetched
// from a database or from static files
var articleList = []article{
article{ID: 1, Title: "Article 1", Content: "Article 1 body"},
article{ID: 2, Title: "Article 2", Content: "Article 2 body"},
}
// Return a list of all the articles
func getAllArticles() []article {
return articleList
}
【修改】「首頁」模板：./templates/index.html
<!--index.html-->
<!--Embed the header.html template at this location-->
{{ template "header.html" .}}
<!--Loop over the `payload` variable, which is the list of articles-->
{{range .payload }}
<!--Create the link for the article based on its ID-->
<a href="/article/view/{{.ID}}">
<!--Display the title of the article -->
<h2>{{.Title}}</h2>
</a>
<!--Display the content of the article-->
<p>{{.Content}}</p>
{{end}}
<!--Embed the footer.html template at this location-->
{{ template "footer.html" .}}
新建 Go 程式碼：./handlers.article.go
// handlers.article.go
package main
import (
"net/http"
"github.com/gin-gonic/gin"
)
func showIndexPage(c *gin.Context) {
articles := getAllArticles()
// Call the HTML method of the Context to render a template
c.HTML(
// Set the HTTP status to 200 (OK)
http.StatusOK,
// Use the index.html template
"index.html",
// Pass the data that the page uses
gin.H{
"title": "Home Page",
"payload": articles,
},
)
}
測試
> go build -o app.exe
> ./app.exe
- 至 localhost:8080 查看
Step 3：建置可查看文章的論壇
【修改】 Go 程式碼：./routes.go
// routes.go
package main
func initializeRoutes() {
// Handle the index route
router.GET("/", showIndexPage)
// Handle GET requests at /article/view/some_article_id
router.GET("/article/view/:article_id", getArticle)
}
新建「文章」模板：./templates/article.html
<!--article.html-->
<!--Embed the header.html template at this location-->
{{ template "header.html" .}}
<!--Display the title of the article-->
<h1>{{.payload.Title}}</h1>
<!--Display the content of the article-->
<p>{{.payload.Content}}</p>
<!--Embed the footer.html template at this location-->
{{ template "footer.html" .}}
【修改】 Go 程式碼：./models.article.go
// models.article.go
package main
import "errors"
type article struct {
ID int `json:"id"`
Title string `json:"title"`
Content string `json:"content"`
}
// For this demo, we're storing the article list in memory
// In a real application, this list will most likely be fetched
// from a database or from static files
var articleList = []article{
article{ID: 1, Title: "Article 1", Content: "Article 1 body"},
article{ID: 2, Title: "Article 2", Content: "Article 2 body"},
}
// Return a list of all the articles
func getAllArticles() []article {
return articleList
}
func getArticleByID(id int) (*article, error) {
for _, a := range articleList {
if a.ID == id {
return &a, nil
}
}
return nil, errors.New("Article not found")
}
【修改】 Go 程式碼：./handlers.article.go
// handlers.article.go
package main
import (
"net/http"
"strconv"
"github.com/gin-gonic/gin"
)
func showIndexPage(c *gin.Context) {
articles := getAllArticles()
// Call the HTML method of the Context to render a template
c.HTML(
// Set the HTTP status to 200 (OK)
http.StatusOK,
// Use the index.html template
"index.html",
// Pass the data that the page uses
gin.H{
"title": "Home Page",
"payload": articles,
},
)
}
func getArticle(c *gin.Context) {
// Check if the article ID is valid
if articleID, err := strconv.Atoi(c.Param("article_id")); err == nil {
// Check if the article exists
if article, err := getArticleByID(articleID); err == nil {
// Call the HTML method of the Context to render a template
c.HTML(
// Set the HTTP status to 200 (OK)
http.StatusOK,
// Use the index.html template
"article.html",
// Pass the data that the page uses
gin.H{
"title": article.Title,
"payload": article,
},
)
} else {
// If the article is not found, abort with an error
c.AbortWithError(http.StatusNotFound, err)
}
} else {
// If an invalid article ID is specified in the URL, abort with an error
c.AbortWithStatus(http.StatusNotFound)
}
}
測試
> go build -o app.exe
> ./app.exe
- 至 localhost:8080 查看
Step 4：建置可回傳 XML、JSON 格式的論壇
【修改】 Go 程式碼：./main.go
package main
import (
"net/http"
"github.com/gin-gonic/gin"
)
var router *gin.Engine
func main() {
// Set the router as the default one provided by Gin
router = gin.Default()
// Process the templates at the start so that they don't have to be loaded
// from the disk again. This makes serving HTML pages very fast.
router.LoadHTMLGlob("templates/*")
// Initialize the routes
initializeRoutes()
// Start serving the application
router.Run()
}
// Render one of HTML, JSON or CSV based on the 'Accept' header of the request
// If the header doesn't specify this, HTML is rendered, provided that
// the template name is present
func render(c *gin.Context, data gin.H, templateName string) {
switch c.Request.Header.Get("Accept") {
case "application/json":
// Respond with JSON
c.JSON(http.StatusOK, data["payload"])
case "application/xml":
// Respond with XML
c.XML(http.StatusOK, data["payload"])
default:
// Respond with HTML
c.HTML(http.StatusOK, templateName, data)
}
}
【修改】 Go 程式碼：./handlers.article.go
// handlers.article.go
package main
import (
"net/http"
"strconv"
"github.com/gin-gonic/gin"
)
func showIndexPage(c *gin.Context) {
articles := getAllArticles()
// Call the render function with the name of the template to render
render(c, gin.H{
"title": "Home Page",
"payload": articles}, "index.html")
}
func getArticle(c *gin.Context) {
// Check if the article ID is valid
if articleID, err := strconv.Atoi(c.Param("article_id")); err == nil {
// Check if the article exists
if article, err := getArticleByID(articleID); err == nil {
// Call the render function with the title, article and the name of the
// template
render(c, gin.H{
"title": article.Title,
"payload": article}, "article.html")
} else {
// If the article is not found, abort with an error
c.AbortWithError(http.StatusNotFound, err)
}
} else {
// If an invalid article ID is specified in the URL, abort with an error
c.AbortWithStatus(http.StatusNotFound)
}
}
測試
> go build -o app.exe
> ./app.exe
- 至 localhost:8080 查看
使用 CMD 測試
> curl -X GET -H "Accept: application/json" http://localhost:8080/
> curl -X GET -H "Accept: application/xml" http://localhost:8080/article/view/1
Step 5：建置的論壇
新建 Go 程式碼：./models.user.go
// models.user.go
package main
import "errors"
type user struct {
Username string `json:"username"`
Password string `json:"-"`
}
var userList = []user{
user{Username: "user1", Password: "pass1"},
user{Username: "user2", Password: "pass2"},
user{Username: "user3", Password: "pass3"},
}
func registerNewUser(username, password string) (*user, error) {
return nil, errors.New("placeholder error")
}
func isUsernameAvailable(username string) bool {
return false
}
新建 Go 程式碼：./handlers.user.go
// handlers.user.go
package main
import "github.com/gin-gonic/gin"
func showRegistrationPage(c *gin.Context) {
}
func register(c *gin.Context) {
}
【修改】 Go 程式碼：./routes.go
// routes.go
package main
func initializeRoutes() {
router.GET("/", showIndexPage)
userRoutes := router.Group("/u")
{
userRoutes.GET("/register", showRegistrationPage)
userRoutes.POST("/register", register)
}
router.GET("/article/view/:article_id", getArticle)
}
新建「註冊使用者」模板：./templates/register.html
<!--register.html-->
<!--Embed the header.html template at this location-->
{{ template "header.html" .}}
<h1>Register</h1>
<div class="panel panel-default col-sm-6">
<div class="panel-body">
<!--If there's an error, display the error-->
{{ if .ErrorTitle}}
<p class="bg-danger">
{{.ErrorTitle}}: {{.ErrorMessage}}
</p>
{{end}}
<!--Create a form that POSTs to the `/u/register` route-->
<form class="form" action="/u/register" method="POST">
<div class="form-group">
<label for="username">Username</label>
<input type="text" class="form-control" id="username" name="username" placeholder="Username">
</div>
<div class="form-group">
<label for="password">Password</label>
<input type="password" name="password" class="form-control" id="password" placeholder="Password">
</div>
<button type="submit" class="btn btn-primary">Register</button>
</form>
</div>
</div>
<!--Embed the footer.html template at this location-->
{{ template "footer.html" .}}
新建「登入成功」模板：./templates/login-successful.html
<!--login-successful.html-->
<!--Embed the header.html template at this location-->
{{ template "header.html" .}}
<div>
You have successfully logged in.
</div>
<!--Embed the footer.html template at this location-->
{{ template "footer.html" .}}
【修改】「功能表」模板：./templates/menu.html
<!--menu.html-->
<nav class="navbar navbar-default">
<div class="container">
<div class="navbar-header">
<a class="navbar-brand" href="/">
Home
</a>
</div>
<ul class="nav navbar-nav">
<li><a href="/u/register">Register</a></li>
</ul>
</div>
</nav>
【修改】Go 程式碼：./models.user.go
// models.user.go
package main
import (
"errors"
"strings"
)
type user struct {
Username string `json:"username"`
Password string `json:"-"`
}
// For this demo, we're storing the user list in memory
// We also have some users predefined.
// In a real application, this list will most likely be fetched
// from a database. Moreover, in production settings, you should
// store passwords securely by salting and hashing them instead
// of using them as we're doing in this demo
var userList = []user{
user{Username: "user1", Password: "pass1"},
user{Username: "user2", Password: "pass2"},
user{Username: "user3", Password: "pass3"},
}
// Register a new user with the given username and password
func registerNewUser(username, password string) (*user, error) {
if strings.TrimSpace(password) == "" {
return nil, errors.New("The password can't be empty")
} else if !isUsernameAvailable(username) {
return nil, errors.New("The username isn't available")
}
u := user{Username: username, Password: password}
userList = append(userList, u)
return &u, nil
}
// Check if the supplied username is available
func isUsernameAvailable(username string) bool {
for _, u := range userList {
if u.Username == username {
return false
}
}
return true
}
【修改】Go 程式碼：./handlers.user.go
// handlers.user.go
package main
import (
"math/rand"
"net/http"
"strconv"
"github.com/gin-gonic/gin"
)
func generateSessionToken() string {
// We're using a random 16 character string as the session token
// This is NOT a secure way of generating session tokens
// DO NOT USE THIS IN PRODUCTION
return strconv.FormatInt(rand.Int63(), 16)
}
func showRegistrationPage(c *gin.Context) {
// Call the render function with the name of the template to render
render(c, gin.H{
"title": "Register"}, "register.html")
}
func register(c *gin.Context) {
// Obtain the POSTed username and password values
username := c.PostForm("username")
password := c.PostForm("password")
if _, err := registerNewUser(username, password); err == nil {
// If the user is created, set the token in a cookie and log the user in
token := generateSessionToken()
c.SetCookie("token", token, 3600, "", "", false, true)
c.Set("is_logged_in", true)
render(c, gin.H{
"title": "Successful registration & Login"}, "login-successful.html")
} else {
// If the username/password combination is invalid,
// show the error message on the login page
c.HTML(http.StatusBadRequest, "register.html", gin.H{
"ErrorTitle": "Registration Failed",
"ErrorMessage": err.Error()})
}
}
【修改】Go 程式碼：./models.user.go
// models.user.go
package main
import (
"errors"
"strings"
)
type user struct {
Username string `json:"username"`
Password string `json:"-"`
}
// For this demo, we're storing the user list in memory
// We also have some users predefined.
// In a real application, this list will most likely be fetched
// from a database. Moreover, in production settings, you should
// store passwords securely by salting and hashing them instead
// of using them as we're doing in this demo
var userList = []user{
user{Username: "user1", Password: "pass1"},
user{Username: "user2", Password: "pass2"},
user{Username: "user3", Password: "pass3"},
}
func isUserValid(username, password string) bool {
return false
}
// Register a new user with the given username and password
func registerNewUser(username, password string) (*user, error) {
if strings.TrimSpace(password) == "" {
return nil, errors.New("The password can't be empty")
} else if !isUsernameAvailable(username) {
return nil, errors.New("The username isn't available")
}
u := user{Username: username, Password: password}
userList = append(userList, u)
return &u, nil
}
// Check if the supplied username is available
func isUsernameAvailable(username string) bool {
for _, u := range userList {
if u.Username == username {
return false
}
}
return true
}
【修改】Go 程式碼：./handlers.user.go
// handlers.user.go
package main
import (
"math/rand"
"net/http"
"strconv"
"github.com/gin-gonic/gin"
)
func showLoginPage(c *gin.Context) {}
func performLogin(c *gin.Context) {}
func logout(c *gin.Context) {}
func generateSessionToken() string {
// We're using a random 16 character string as the session token
// This is NOT a secure way of generating session tokens
// DO NOT USE THIS IN PRODUCTION
return strconv.FormatInt(rand.Int63(), 16)
}
func showRegistrationPage(c *gin.Context) {
// Call the render function with the name of the template to render
render(c, gin.H{
"title": "Register"}, "register.html")
}
func register(c *gin.Context) {
// Obtain the POSTed username and password values
username := c.PostForm("username")
password := c.PostForm("password")
if _, err := registerNewUser(username, password); err == nil {
// If the user is created, set the token in a cookie and log the user in
token := generateSessionToken()
c.SetCookie("token", token, 3600, "", "", false, true)
c.Set("is_logged_in", true)
render(c, gin.H{
"title": "Successful registration & Login"}, "login-successful.html")
} else {
// If the username/password combination is invalid,
// show the error message on the login page
c.HTML(http.StatusBadRequest, "register.html", gin.H{
"ErrorTitle": "Registration Failed",
"ErrorMessage": err.Error()})
}
}
【修改】 Go 程式碼：./routes.go
// routes.go
package main
func initializeRoutes() {
router.GET("/", showIndexPage)
userRoutes := router.Group("/u")
{
userRoutes.GET("/register", showRegistrationPage)
userRoutes.POST("/register", register)
userRoutes.GET("/login", showLoginPage)
userRoutes.POST("/login", performLogin)
userRoutes.GET("/logout", logout)
}
router.GET("/article/view/:article_id", getArticle)
}
新建「登入」模板：./templates/login.html
<!--login.html-->
{{ template "header.html" .}}
<h1>Login</h1>
<div class="panel panel-default col-sm-6">
<div class="panel-body">
{{ if .ErrorTitle}}
<p class="bg-danger">
{{.ErrorTitle}}: {{.ErrorMessage}}
</p>
{{end}}
<form class="form" action="/u/login" method="POST">
<div class="form-group">
<label for="username">Username</label>
<input type="text" class="form-control" id="username" name="username" placeholder="Username">
</div>
<div class="form-group">
<label for="password">Password</label>
<input type="password" class="form-control" id="password" name="password" placeholder="Password">
</div>
<button type="submit" class="btn btn-primary">Login</button>
</form>
</div>
</div>
{{ template "footer.html" .}}
【修改】「功能表」模板：./templates/menu.html
<!--menu.html-->
<nav class="navbar navbar-default">
<div class="container">
<div class="navbar-header">
<a class="navbar-brand" href="/">
Home
</a>
</div>
<ul class="nav navbar-nav">
<li><a href="/u/register">Register</a></li>
<li><a href="/u/login">Login</a></li>
<li><a href="/u/logout">Logout</a></li>
</ul>
</div>
</nav>
【修改】Go 程式碼：./models.user.go
// models.user.go
package main
import (
"errors"
"strings"
)
type user struct {
Username string `json:"username"`
Password string `json:"-"`
}
// For this demo, we're storing the user list in memory
// We also have some users predefined.
// In a real application, this list will most likely be fetched
// from a database. Moreover, in production settings, you should
// store passwords securely by salting and hashing them instead
// of using them as we're doing in this demo
var userList = []user{
user{Username: "user1", Password: "pass1"},
user{Username: "user2", Password: "pass2"},
user{Username: "user3", Password: "pass3"},
}
func isUserValid(username, password string) bool {
for _, u := range userList {
if u.Username == username && u.Password == password {
return true
}
}
return false
}
// Register a new user with the given username and password
func registerNewUser(username, password string) (*user, error) {
if strings.TrimSpace(password) == "" {
return nil, errors.New("The password can't be empty")
} else if !isUsernameAvailable(username) {
return nil, errors.New("The username isn't available")
}
u := user{Username: username, Password: password}
userList = append(userList, u)
return &u, nil
}
// Check if the supplied username is available
func isUsernameAvailable(username string) bool {
for _, u := range userList {
if u.Username == username {
return false
}
}
return true
}
【修改】Go 程式碼：./handlers.user.go
// handlers.user.go
package main
import (
"math/rand"
"net/http"
"strconv"
"github.com/gin-gonic/gin"
)
func showLoginPage(c *gin.Context) {
render(c, gin.H{
"title": "Login",
}, "login.html")
}
func performLogin(c *gin.Context) {
username := c.PostForm("username")
password := c.PostForm("password")
if isUserValid(username, password) {
token := generateSessionToken()
c.SetCookie("token", token, 3600, "", "", false, true)
render(c, gin.H{
"title": "Successful Login"}, "login-successful.html")
} else {
c.HTML(http.StatusBadRequest, "login.html", gin.H{
"ErrorTitle": "Login Failed",
"ErrorMessage": "Invalid credentials provided"})
}
}
func logout(c *gin.Context) {
c.SetCookie("token", "", -1, "", "", false, true)
c.Redirect(http.StatusTemporaryRedirect, "/")
}
func generateSessionToken() string {
// We're using a random 16 character string as the session token
// This is NOT a secure way of generating session tokens
// DO NOT USE THIS IN PRODUCTION
return strconv.FormatInt(rand.Int63(), 16)
}
func showRegistrationPage(c *gin.Context) {
// Call the render function with the name of the template to render
render(c, gin.H{
"title": "Register"}, "register.html")
}
func register(c *gin.Context) {
// Obtain the POSTed username and password values
username := c.PostForm("username")
password := c.PostForm("password")
if _, err := registerNewUser(username, password); err == nil {
// If the user is created, set the token in a cookie and log the user in
token := generateSessionToken()
c.SetCookie("token", token, 3600, "", "", false, true)
c.Set("is_logged_in", true)
render(c, gin.H{
"title": "Successful registration & Login"}, "login-successful.html")
} else {
// If the username/password combination is invalid,
// show the error message on the login page
c.HTML(http.StatusBadRequest, "register.html", gin.H{
"ErrorTitle": "Registration Failed",
"ErrorMessage": err.Error()})
}
}
【修改】 Go 程式碼：./models.article.go
// models.article.go
package main
import "errors"
type article struct {
ID int `json:"id"`
Title string `json:"title"`
Content string `json:"content"`
}
// For this demo, we're storing the article list in memory
// In a real application, this list will most likely be fetched
// from a database or from static files
var articleList = []article{
article{ID: 1, Title: "Article 1", Content: "Article 1 body"},
article{ID: 2, Title: "Article 2", Content: "Article 2 body"},
}
// Return a list of all the articles
func getAllArticles() []article {
return articleList
}
func getArticleByID(id int) (*article, error) {
for _, a := range articleList {
if a.ID == id {
return &a, nil
}
}
return nil, errors.New("Article not found")
}
func createNewArticle(title, content string) (*article, error) {
return nil, nil
}
【修改】 Go 程式碼：./handlers.article.go
// handlers.article.go
package main
import (
"net/http"
"strconv"
"github.com/gin-gonic/gin"
)
func showIndexPage(c *gin.Context) {
articles := getAllArticles()
// Call the render function with the name of the template to render
render(c, gin.H{
"title": "Home Page",
"payload": articles}, "index.html")
}
func showArticleCreationPage(c *gin.Context) {}
func getArticle(c *gin.Context) {
// Check if the article ID is valid
if articleID, err := strconv.Atoi(c.Param("article_id")); err == nil {
// Check if the article exists
if article, err := getArticleByID(articleID); err == nil {
// Call the render function with the title, article and the name of the
// template
render(c, gin.H{
"title": article.Title,
"payload": article}, "article.html")
} else {
// If the article is not found, abort with an error
c.AbortWithError(http.StatusNotFound, err)
}
} else {
// If an invalid article ID is specified in the URL, abort with an error
c.AbortWithStatus(http.StatusNotFound)
}
}
func createArticle(c *gin.Context) {}
【修改】 Go 程式碼：./routes.go
// routes.go
package main
func initializeRoutes() {
router.GET("/", showIndexPage)
userRoutes := router.Group("/u")
{
userRoutes.GET("/register", showRegistrationPage)
userRoutes.POST("/register", register)
userRoutes.GET("/login", showLoginPage)
userRoutes.POST("/login", performLogin)
userRoutes.GET("/logout", logout)
}
articleRoutes := router.Group("/article")
{
// route from Part 1 of the tutorial
articleRoutes.GET("/view/:article_id", getArticle)
articleRoutes.GET("/create", showArticleCreationPage)
articleRoutes.POST("/create", createArticle)
}
}
新建「新增文章」模板：./templates/create-article.html
<!--create-article.html-->
{{ template "header.html" .}}
<h1>Create Article</h1>
<div class="panel panel-default col-sm-12">
<div class="panel-body">
{{ if .ErrorTitle}}
<p class="bg-danger">
{{.ErrorTitle}}: {{.ErrorMessage}}
</p>
{{end}}
<form class="form" action="/article/create" method="POST">
<div class="form-group">
<label for="title">Username</label>
<input type="text" class="form-control" id="title" name="title" placeholder="Title">
</div>
<div class="form-group">
<label for="content">Password</label>
<textarea name="content" class="form-control" rows="10" id="content" laceholder="Article Content"></textarea>
</div>
<button type="submit" class="btn btn-primary">Submit</button>
</form>
</div>
</div>
{{ template "footer.html" .}}
新建「送出文章」模板：./templates/submission-successful.html
<!--submission-successful.html-->
{{ template "header.html" .}}
<div>
<strong>The article was successfully submitted.</strong>
<a href="/article/view/{{.payload.ID}}">{{.payload.Title}}</a>
</div>
{{ template "footer.html" .}}
【修改】「功能表」模板：./templates/menu.html
<!--menu.html-->
<nav class="navbar navbar-default">
<div class="container">
<div class="navbar-header">
<a class="navbar-brand" href="/">
Home
</a>
</div>
<ul class="nav navbar-nav">
<li><a href="/article/create">Create Article</a></li>
<li><a href="/u/register">Register</a></li>
<li><a href="/u/login">Login</a></li>
<li><a href="/u/logout">Logout</a></li>
</ul>
</div>
</nav>
【修改】 Go 程式碼：./models.article.go
// models.article.go
package main
import "errors"
type article struct {
ID int `json:"id"`
Title string `json:"title"`
Content string `json:"content"`
}
// For this demo, we're storing the article list in memory
// In a real application, this list will most likely be fetched
// from a database or from static files
var articleList = []article{
article{ID: 1, Title: "Article 1", Content: "Article 1 body"},
article{ID: 2, Title: "Article 2", Content: "Article 2 body"},
}
// Return a list of all the articles
func getAllArticles() []article {
return articleList
}
func getArticleByID(id int) (*article, error) {
for _, a := range articleList {
if a.ID == id {
return &a, nil
}
}
return nil, errors.New("Article not found")
}
func createNewArticle(title, content string) (*article, error) {
a := article{ID: len(articleList) + 1, Title: title, Content: content}
articleList = append(articleList, a)
return &a, nil
}
【修改】 Go 程式碼：./handlers.article.go
// handlers.article.go
package main
import (
"net/http"
"strconv"
"github.com/gin-gonic/gin"
)
func showIndexPage(c *gin.Context) {
articles := getAllArticles()
// Call the render function with the name of the template to render
render(c, gin.H{
"title": "Home Page",
"payload": articles}, "index.html")
}
func showArticleCreationPage(c *gin.Context) {
render(c, gin.H{
"title": "Create New Article"}, "create-article.html")
}
func getArticle(c *gin.Context) {
// Check if the article ID is valid
if articleID, err := strconv.Atoi(c.Param("article_id")); err == nil {
// Check if the article exists
if article, err := getArticleByID(articleID); err == nil {
// Call the render function with the title, article and the name of the
// template
render(c, gin.H{
"title": article.Title,
"payload": article}, "article.html")
} else {
// If the article is not found, abort with an error
c.AbortWithError(http.StatusNotFound, err)
}
} else {
// If an invalid article ID is specified in the URL, abort with an error
c.AbortWithStatus(http.StatusNotFound)
}
}
func createArticle(c *gin.Context) {
title := c.PostForm("title")
content := c.PostForm("content")
if a, err := createNewArticle(title, content); err == nil {
render(c, gin.H{
"title": "Submission Successful",
"payload": a}, "submission-successful.html")
} else {
c.AbortWithStatus(http.StatusBadRequest)
}
}
Step 5：建置的論壇
新建 Go 程式碼：./middleware.auth.go
// middleware.auth.go
package main
import "github.com/gin-gonic/gin"
func ensureLoggedIn() gin.HandlerFunc {
return func(c *gin.Context) {
}
}
func ensureNotLoggedIn() gin.HandlerFunc {
return func(c *gin.Context) {
}
}
func setUserStatus() gin.HandlerFunc {
return func(c *gin.Context) {
}
}
【修改】Go 程式碼：./middleware.auth.go
// middleware.auth.go
package main
import "github.com/gin-gonic/gin"
func ensureLoggedIn() gin.HandlerFunc {
return func(c *gin.Context) {
loggedInInterface, _ := c.Get("is_logged_in")
loggedIn := loggedInInterface.(bool)
if !loggedIn {
c.AbortWithStatus(http.StatusUnauthorized)
}
}
}
func ensureNotLoggedIn() gin.HandlerFunc {
return func(c *gin.Context) {
loggedInInterface, _ := c.Get("is_logged_in")
loggedIn := loggedInInterface.(bool)
if loggedIn {
c.AbortWithStatus(http.StatusUnauthorized)
}
}
}
func setUserStatus() gin.HandlerFunc {
return func(c *gin.Context) {
if token, err := c.Cookie("token"); err == nil || token != "" {
c.Set("is_logged_in", true)
} else {
c.Set("is_logged_in", false)
}
}
}
【修改】 Go 程式碼：./routes.go
// routes.go
package main
func initializeRoutes() {
router.Use(setUserStatus())
router.GET("/", showIndexPage)
userRoutes := router.Group("/u")
{
userRoutes.GET("/login", ensureNotLoggedIn(), showLoginPage)
userRoutes.POST("/login", ensureNotLoggedIn(), performLogin)
userRoutes.GET("/logout", ensureLoggedIn(), logout)
userRoutes.GET("/register", ensureNotLoggedIn(), showRegistrationPage)
userRoutes.POST("/register", ensureNotLoggedIn(), register)
}
articleRoutes := router.Group("/article")
{
articleRoutes.GET("/view/:article_id", getArticle)
articleRoutes.GET("/create", ensureLoggedIn(), showArticleCreationPage)
articleRoutes.POST("/create", ensureLoggedIn(), createArticle)
}
}
【修改】「功能表」模板：./templates/menu.html
<!--menu.html-->
<nav class="navbar navbar-default">
<div class="container">
<div class="navbar-header">
<a class="navbar-brand" href="/">
Home
</a>
</div>
<ul class="nav navbar-nav">
{{ if .is_logged_in }}
<!--Display this link only when the user is logged in-->
<li><a href="/article/create">Create Article</a></li>
{{end}}
{{ if not .is_logged_in }}
<!--Display this link only when the user is not logged in-->
<li><a href="/u/register">Register</a></li>
{{end}}
{{ if not .is_logged_in }}
<!--Display this link only when the user is not logged in-->
<li><a href="/u/login">Login</a></li>
{{end}}
{{ if .is_logged_in }}
<!--Display this link only when the user is logged in-->
<li><a href="/u/logout">Logout</a></li>
{{end}}
</ul>
</div>
</nav>