go - 当我传递中间件配置时，如何允许 Buffalo (gobuffalo) 中间件使用 skip() 方法？

Question

我正在尝试创建一个接受正在运行的配置的自定义 Buffalo (gobuffalo) 中间件。问题是我无法通过此错误跳过中间件功能:

actions/app.go:63:22: 不能在 app.Middleware.Skip 的参数中使用 myMiddlewareFunc(类型 func(myConfig) buffalo.MiddlewareFunc)作为类型 buffalo.MiddlewareFunc

到目前为止我得到的代码是:

package actions

import (
    "github.com/gobuffalo/buffalo"
    "github.com/gobuffalo/buffalo/middleware"
    "github.com/gobuffalo/envy"

    "github.com/gobuffalo/buffalo/middleware/csrf"
    "github.com/gobuffalo/buffalo/middleware/i18n"
    "github.com/gobuffalo/packr"
)

// ENV is used to help switch settings based on where the
// application is being run. Default is "development".
var ENV = envy.Get("GO_ENV", "development")
var app *buffalo.App
var T *i18n.Translator

type myConfig struct {
    value string
}

// App is where all routes and middleware for buffalo
// should be defined. This is the nerve center of your
// application.
func App() *buffalo.App {
    if app == nil {
        app = buffalo.New(buffalo.Options{
            Env:         ENV,
            SessionName: "_myapp_session",
        })
        // Automatically redirect to SSL
        app.Use(ssl.ForceSSL(secure.Options{
            SSLRedirect:     ENV == "production",
            SSLProxyHeaders: map[string]string{"X-Forwarded-Proto": "https"},
        }))

        if ENV == "development" {
            app.Use(middleware.ParameterLogger)
        }

        // Protect against CSRF attacks. https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)
        // Remove to disable this.
        app.Use(csrf.New)

        // Wraps each request in a transaction.
        //  c.Value("tx").(*pop.PopTransaction)
        // Remove to disable this.
        app.Use(middleware.PopTransaction(models.DB))

        // Setup and use translations:
        var err error
        if T, err = i18n.New(packr.NewBox("../locales"), "en-US"); err != nil {
            app.Stop(err)
        }
        app.Use(T.Middleware())
        app.Use(myMiddlewareFunc(myConfig{
            value: "test value",
        }))
        app.Middleware.Skip(myMiddlewareFunc, TestHandler)
        app.GET("/", HomeHandler)
        app.GET("/test", TestHandler)

        app.ServeFiles("/assets", assetsBox)
    }

    return app
}

// TestHandler is a test handler
func TestHandler(c buffalo.Context) error {
    return c.Render(200, r.String("Test1234"))
}

func myMiddlewareFunc(config myConfig) buffalo.MiddlewareFunc {
    return func(next buffalo.Handler) buffalo.Handler {
        return func(c buffalo.Context) error {
            c.Logger().Info("Test ", config.value)

            return next(c)
        }
    }
}

所以@ttomalak 创建一个带有接收器的方法的方法和下面的两个方法一样有效:

    mw := myMiddlewareFunc(myConfig{
        value: "test value",
    })
    app.Use(mw)
    app.Middleware.Skip(mw, TestHandler)

和

    config := myConfig{
        value: "test value",
    }
    app.Use(myMiddlewareFunc(config))
    app.Middleware.Skip(myMiddlewareFunc(config), TestHandler)

所有方式需要调用中间件方法。不能使用此处显示的方法:

a.Middleware.Skip(Authorization, HomeHandler, ...)

https://github.com/gobuffalo/buffalo/blob/master/middleware.go#L77

我是新手，但我的感觉是这些方法不符合 MiddlewareFunc 接口(interface)，因此调用它们并获取返回类型 buffalo.MiddlewareFunc 是允许它工作的原因。

Answer 1

您需要稳定所需的 func 但您需要无法传递的额外参数。您可能可以通过将 myConfig 作为 myMiddlewareFunc 的接收者来改变您的处理方式，我的意思是:

type myConfig struct {
    value string
}

func (config *myConfig) myMiddlewareFunc() buffalo.MiddlewareFunc {
    return func(next buffalo.Handler) buffalo.Handler {
        return func(c buffalo.Context) error {
            c.Logger().Info("Test ", config.value)

            return next(c)
        }
    }
}


func App() *buffalo.App {
    if app == nil {
        app = buffalo.New(buffalo.Options{
            Env:         ENV,
            SessionName: "_myapp_session",
        })
        // Automatically redirect to SSL
        app.Use(ssl.ForceSSL(secure.Options{
            SSLRedirect:     ENV == "production",
            SSLProxyHeaders: map[string]string{"X-Forwarded-Proto": "https"},
        }))

        if ENV == "development" {
            app.Use(middleware.ParameterLogger)
        }

        // Protect against CSRF attacks. https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)
        // Remove to disable this.
        app.Use(csrf.New)

        // Wraps each request in a transaction.
        //  c.Value("tx").(*pop.PopTransaction)
        // Remove to disable this.
        app.Use(middleware.PopTransaction(models.DB))

        // Setup and use translations:
        var err error
        if T, err = i18n.New(packr.NewBox("../locales"), "en-US"); err != nil {
            app.Stop(err)
        }
        app.Use(T.Middleware())

        c := &myConfig{
            value: "test value",
        }
        app.Use(c.myMiddlewareFunc())
        app.Middleware.Skip(c.myMiddlewareFunc(), TestHandler)


        app.GET("/", HomeHandler)
        app.GET("/test", TestHandler)

        app.ServeFiles("/assets", assetsBox)
    }

    return app
}