我正在尝试编写一个 Web 应用程序并努力编写干净的代码。

我有一个用于处理传入请求的 Controller 和一个所有 Controller 都将借用字段的基本 Controller 。

这是我的基本 Controller

type Controller struct {
    Request  *http.Request
    Response http.ResponseWriter

    // Reqeust language
    lang string

    // HTML parts
    Title   string
    body    string
    head    string
    content string
    view    string
    errors  []string
    success []string
}
// And methods followed here
func (self *Controller) renderHeadView() { .....

和我的注册 Controller

type Controller struct {
    base.Controller
    user *account
}

func (self *Controller) ServeHTTP(rw http.ResponseWriter, r *http.Request) {

    self.Title = "Sign Up"
    self.Request = r
    self.Response = rw

    self.lang = header.Language(self.Request)
    self.user = &account{lang: self.lang}

    switch self.Request.Method {
    case "GET":
        self.get()
    case "POST":
        if err := self.post(); err != nil {
            self.get()
        } else {
            // If everything was successfully
            return
        }

    }
    self.RenderResponseView()
}

和我的激活 Controller

type Controller struct {
    base.Controller
}

func (self *Controller) ServeHTTP(rw http.ResponseWriter, r *http.Request) {

    self.Title = "Activate account"
    self.Request = r
    self.Response = rw
    self.lang = header.Language(self.Request)

    self.RenderResponseView()
}

如您所见，ServeHTTP 方法看起来几乎相同。我正在考虑将 ServeHTTP 移动到基本 Controller 中，然后提供一种调用特殊工作的方法。为了阐明我的意思，请看下面的代码片段(基本 Controller )

func (self *Controller) ServeHTTP(rw http.ResponseWriter, r *http.Request) {

    self.Title = "Activate account"
    self.Request = r
    self.Response = rw
    self.lang = header.Language(self.Request)

    // here would come function for special work
    function()
    self.RenderResponseView()
}

我不知道如何提供这个实现。如果有人能给我一些建议，我会很高兴。

最佳答案

可以引用的好文章是“Middlewares in Go: Best practices and examples”

The first code smell we encounter when writing a web application in Go is code duplication.
Before processing the request, we will often need to log the request, convert app errors into HTTP 500 errors, authenticate users, etc. And we need to do most of these things for each handler.

We could create a function with a closure. But if we have multiple functions like that, it will become as bad as callback spaghetti in Javascript. We don't want that.

So we can write a handler and pass another handler to it.

loggingHandler(recoverHandler(indexHandler))

So a middleware would be something like func (http.Handler) http.Handler
This way we pass a handler and returns a handler. At the end we have one handler and can be called with http.Handle(pattern, handler)

爱丽丝

Alice is a small package to chain handlers more elegantly. Furthermore, we can create a common list of handlers and reuse them for each route like this:

func main() {
  commonHandlers := alice.New(loggingHandler, recoverHandler)
  http.Handle("/about", commonHandlers.ThenFunc(aboutHandler))
  http.Handle("/", alice.New(commonHandlers, bodyParserHandler).ThenFunc(indexHandler))
  http.ListenAndServe(":8080", nil)
}

Problem solved. We now have a middleware system that is idiomatic and use standard interfaces. Alice is 50 lines of code, so it is a very small dependency.

关于go - 避免代码重复，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26926488/