如何在Go中将参数传递给Alice中间件？

Question

I am using justinas/alice middleware in Go, and I want to pass arguments to the function used in the middleware.

For example:

middlewareChain := alice.New(Func1(foo string,foo2 string))

How can I do that?

Answer 1

As mentioned by Motakjuq, you can't directly write a middleware that takes in options as an argument since they need to be of the signature func (http.Handler) http.Handler.

What you can do is make a function that generates your middleware function.

func middlewareGenerator(foo, foo2 string) (mw func(http.Handler) http.Handler) {

    mw = func(h http.Handler) http.Handler {
        return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            // Use foo1 & foo2
            h.ServeHTTP(w, r)
        })
    }
    return
}

Then you can do the following

middlewareChain := alice.New(middlewareGenerator("foo","foo2"))