7 Days Go Web Framework Gee from Scratch

7天用Go从零实现Web框架Gee

Content

• 第一天：前置知识(http.Handler接口)
• 第二天：上下文设计(Context)
• 第三天：Trie树路由(Router)
• 第四天：分组控制(Group)
• 第五天：中间件(Middleware)
• 第六天：HTML模板(Template)
• 第七天：错误恢复(Panic Recover)

Day 1 - Static Route

func main() {
    r := gee.New()
    r.GET("/", func(w http.ResponseWriter, req *http.Request) {
        fmt.Fprintf(w, "URL.Path = %q\n", req.URL.Path)
    })
    r.GET("/hello", func(w http.ResponseWriter, req *http.Request) {
        for k, v := range req.Header {
            fmt.Fprintf(w, "Header[%q] = %q\n", k, v)
        }
    })
    r.Run(":9999")
}

Day 2 - Context Design

func main() {
    r := gee.New()
    r.GET("/", func(c *gee.Context) {
        c.HTML(http.StatusOK, "<h1>Hello Gee</h1>")
    })
    r.GET("/hello", func(c *gee.Context) {
        // expect /hello?name=geektutu
        c.String(http.StatusOK, "hello %s, you're at %s\n", c.Query("name"), c.Path)
    })
    r.POST("/login", func(c *gee.Context) {
        c.JSON(http.StatusOK, &map[string]string{
            "username": c.PostForm("username"),
            "password": c.PostForm("password"),
        })
    })
    r.Run(":9999")
}

Day 3 - Dynamic Route

func main() {
    r := gee.New()
    r.GET("/", func(c *gee.Context) {
        c.HTML(http.StatusOK, "<h1>Hello Gee</h1>")
    })
    r.GET("/hello", func(c *gee.Context) {
        // expect /hello?name=geektutu
        c.String(http.StatusOK, "hello %s, you're at %s\n", c.Query("name"), c.Path)
    })
    r.GET("/hello/:name", func(c *gee.Context) {
        // expect /hello/geektutu
        c.String(http.StatusOK, "hello %s, you're at %s\n", c.Param("name"), c.Path)
    })
    r.GET("/assets/*filepath", func(c *gee.Context) {
        c.JSON(http.StatusOK, gee.H{"filepath": c.Param("filepath")})
    })
    r.Run(":9999")
}

Day 4 - Nesting Group Control

func main() {
    r := gee.New()
    v1 := r.Group("/v1")
    {
        v1.GET("/", func(c *gee.Context) {
            c.HTML(http.StatusOK, "<h1>Hello Gee</h1>")
        })
        v1.GET("/hello", func(c *gee.Context) {
            // expect /hello?name=geektutu
            c.String(http.StatusOK, "hello %s, you're at %s\n", c.Query("name"), c.Path)
        })
    }
    v2 := r.Group("/v2")
    {
        v2.GET("/hello/:name", func(c *gee.Context) {
            // expect /hello/geektutu
            c.String(http.StatusOK, "hello %s, you're at %s\n", c.Param("name"), c.Path)
        })
        v2.POST("/login", func(c *gee.Context) {
            c.JSON(http.StatusOK, &map[string]string{
                "username": c.PostForm("username"),
                "password": c.PostForm("password"),
            })
        })
    }
    r.Run(":9999")
}

Day 5 - Middleware

func onlyForV2() gee.HandlerFunc {
    return func(c *gee.Context) {
        // Start timer
        t := time.Now()
        // if a server error occurred
        c.Fail(500, "Internal Server Error")
        // Calculate resolution time
        log.Printf("[%d] %s in %v for group v2", c.StatusCode, c.Req.RequestURI, time.Since(t))
    }
}
func main() {
    r := gee.New()
    r.Use(gee.Logger()) // global midlleware
    r.GET("/", func(c *gee.Context) {
        c.HTML(http.StatusOK, "<h1>Hello Gee</h1>")
    })
    v2 := r.Group("/v2")
    v2.Use(onlyForV2()) // v2 group middleware
    {
        v2.GET("/hello/:name", func(c *gee.Context) {
            // expect /hello/geektutu
            c.String(http.StatusOK, "hello %s, you're at %s\n", c.Param("name"), c.Path)
        })
    }
    r.Run(":9999")
}

Day 6 - HTML Template

type student struct {
    Name string
    Age  int8
}
func FormatAsDate(t time.Time) string {
    year, month, day := t.Date()
    return fmt.Sprintf("%d-%02d-%02d", year, month, day)
}
func main() {
    r := gee.New()
    r.Use(gee.Logger())
    r.SetFuncMap(template.FuncMap{
        "FormatAsDate": FormatAsDate,
    })
    r.LoadHTMLGlob("templates/*")
    r.Static("/assets", "./static")
    stu1 := &student{Name: "Geektutu", Age: 20}
    stu2 := &student{Name: "Jack", Age: 22}
    r.GET("/", func(c *gee.Context) {
        c.HTML(http.StatusOK, "css.tmpl", nil)
    })
    r.GET("/students", func(c *gee.Context) {
        c.HTML(http.StatusOK, "arr.tmpl", gee.H{
            "title":  "gee",
            "stuArr": [2]*student{stu1, stu2},
        })
    })
    r.GET("/date", func(c *gee.Context) {
        c.HTML(http.StatusOK, "custom_func.tmpl", gee.H{
            "title": "gee",
            "now":   time.Date(2019, 8, 17, 0, 0, 0, 0, time.UTC),
        })
    })
    r.Run(":9999")
}

Day 7 - Panic Recover

func main() {
    r := gee.Default()
    r.GET("/", func(c *gee.Context) {
        c.String(http.StatusOK, "Hello Geektutu\n")
    })
    // index out of range for testing Recovery()
    r.GET("/panic", func(c *gee.Context) {
        names := []string{"geektutu"}
        c.String(http.StatusOK, names[100])
    })
    r.Run(":9999")
}