尝试将字符串转换为实例变量

问题描述：

I'm new to GO language. Trying to learn GO by building real web application. I'm using revel framework.

And here is my resource routes:

GET     /resource/:resource                     Resource.ReadAll
GET     /resource/:resource/:id                 Resource.Read
POST    /resource/:resource                     Resource.Create
PUT     /resource/:resource/:id                 Resource.Update
DELETE  /resource/:resource/:id                 Resource.Delete

for example:

GET /resource/users calls Resource.ReadAll("users")

And this is my Resource controller (it's just a dummy actions for now):

type Resource struct {
    *revel.Controller
}

type User struct {
    Id int
    Username string
    Password string
}

type Users struct {}

func (u Users) All() string {
        return "All"
}

func (c Resource) ReadAll(resource string) revel.Result {
    fmt.Printf("GET %s", resource)
    model := reflect.New(resource)
    fmt.Println(model.All())
    return nil
}

I'm trying get instance of Users struct by converting resource string to object to call All function.

and the error:

cannot use resource (type string) as type reflect.Type in argument to reflect.New: string does not implement reflect.Type (missing Align method)

I'm new to GO please don't judge me :)

我是GO语言的新手。尝试通过构建真实的Web应用程序来学习GO。我正在使用启示框架。 p>

这是我的资源路线： p>

  GET / resource /：resource Resource.ReadAll 
GET / resource /：  resource /：id Resource.Read 
POST / resource /：resource Resource.Create 
PUT / resource /：resource /：id Resource.Update 
DELETE / resource /：resource /：id Resource.Delete 
  code>  
 
 例如： p> 
 
 
 GET / resource / users调用Resource.ReadAll（“ users”） p> 
 
 
 这是我的资源控制器（目前只是一个虚拟操作）： p> 
 
 
  type资源结构{
 * revel.Controller 
} 
 
type用户结构{\  n ID int 
用户名字符串
密码字符串
} 
 
type用户结构{} 
 
func（u Users）All（）字符串{
返回“全部” 
} 
 
func（c 资源）ReadAll（资源字符串）revel.Res  ult {
 fmt.Printf（“ GET％s”，资源）
模型：= reflect.New（资源）
 fmt.Println（model.All（））
返回nil 
} 
  代码>  pre> 
 
 我正在尝试通过将资源字符串 strong>转换为对象以调用 All  strong>函数来获取Users结构的实例。
 p> 
 
 
和错误： p> 
 
 

 
 不能使用资源（类型字符串）作为反射类型。 新增：字符串未实现reflect.Type（缺少Align 
方法） p> 
  blockquote> 
 
 
我是GO新手，请不要判断我：） p  > 
  div>

答

Your problem is here:

model := reflect.New(resource)

You can't instantiate a type from a string that way. You need to either use a switch there and do stuff depending on the model:

switch resource {
case "users":
    model := &Users{}
    fmt.Println(model.All())
case "posts":
    // ...
}

Or use reflect correctly. Something like:

var types = map[string]reflect.Type{
    "users": reflect.TypeOf(Users{}) // Or &Users{}.
}

// ...

model := reflect.New(types[resource])
res := model.MethodByName("All").Call(nil)
fmt.Println(res)

尝试将字符串转换为实例变量

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