如何在Golang中实现Web表单自动填充

package main

import (
    "html/template"
    "net/http"
)

type User struct {
    Name  string
    Email string
    Age   int
}

func formHandler(w http.ResponseWriter, r *http.Request) {
    user := User{
        Name:  "张三",
        Email: "zhangsan@example.com",
        Age:   25,
    }

    tmpl := `
<form method="post">
    <input type="text" name="name" value="{{.Name}}" placeholder="姓名"><br>
    <input type="email" name="email" value="{{.Email}}" placeholder="邮箱"><br>
    <input type="number" name="age" value="{{.Age}}" placeholder="年龄"><br>
    <button type="submit">提交</button>
</form>
`
    t := template.Must(template.New("form").Parse(tmpl))
    t.Execute(w, user)
}

func main() {
    http.HandleFunc("/form", formHandler)
    http.ListenAndServe(":8080", nil)
}

func submitHandler(w http.ResponseWriter, r *http.Request) {
    if r.Method == "POST" {
        name := r.FormValue("name")
        email := r.FormValue("email")
        age := r.FormValue("age")

        // 模拟验证失败
        if name == "" {
            // 重新渲染表单并保留输入
            tmpl := `
<form method="post">
    <input type="text" name="name" value="{{.Name}}" placeholder="姓名"><br>
    <input type="email" name="email" value="{{.Email}}" placeholder="邮箱"><br>
    <input type="number" name="age" value="{{.Age}}" placeholder="年龄"><br>
    <span style="color:red;">姓名不能为空</span>
    <button type="submit">提交</button>
</form>
`
            data := struct{ Name, Email, Age string }{name, email, age}
            t := template.Must(template.New("form").Parse(tmpl))
            t.Execute(w, data)
            return
        }
        // 处理成功逻辑...
    }
}

<form method="post">
    <input type="text" name="name" value="{{.Name}}"><br>
    <input type="email" name="email" value="{{.Email}}"><br>
    <input type="number" name="age" value="{{.Age}}"><br>
    <button type="submit">提交</button>
</form>

t, _ := template.ParseFiles("form.html")
t.Execute(w, user)