http - 将参数传递给 http.HandlerFunc

Question

我正在使用 Go 的内置 http 服务器和 pat响应某些 URL:

mux.Get("/products", http.HandlerFunc(index))

func index(w http.ResponseWriter, r *http.Request) {
    // Do something.
}

---

我需要向这个处理函数传递一个额外的参数——一个接口(interface)。

func (api Api) Attach(resourceManager interface{}, route string) {
    // Apply typical REST actions to Mux.
    // ie: Product - to /products
    mux.Get(route, http.HandlerFunc(index(resourceManager)))

    // ie: Product ID: 1 - to /products/1
    mux.Get(route+"/:id", http.HandlerFunc(show(resourceManager)))
}

func index(w http.ResponseWriter, r *http.Request, resourceManager interface{}) {
    managerType := string(reflect.TypeOf(resourceManager).String())
    w.Write([]byte(fmt.Sprintf("%v", managerType)))
}

func show(w http.ResponseWriter, r *http.Request, resourceManager interface{}) {
    managerType := string(reflect.TypeOf(resourceManager).String())
    w.Write([]byte(fmt.Sprintf("%v", managerType)))
}

如何向处理函数发送额外的参数？

Answer 1

你应该能够通过使用闭包来做你想做的事。

将 func index() 更改为以下内容(未经测试):

func index(resourceManager interface{}) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        managerType := string(reflect.TypeOf(resourceManager).String())
        w.Write([]byte(fmt.Sprintf("%v", managerType)))
    }
}

然后对func show()做同样的事情