0x4b53/amqp-rpc

package amqprpc

/*
ServerMiddlewareFunc represent a function that can be used as a middleware.

For example:

    func myMiddle(next HandlerFunc) HandlerFunc {

        // Preinitialization of middleware here.

        return func(ctx context.Context, rw *ResponseWriter d amqp.Delivery) {
            // Before handler execution here.

            // Execute the handler.
            next(ctx, rw, d)

            // After execution here.
        }
    }

    s := New("url")

    // Add middleware to specific handler.
    s.Bind(DirectBinding("foobar", myMiddle(HandlerFunc)))

    // Add middleware to all handlers on the server.
    s.AddMiddleware(myMiddle)
*/
type ServerMiddlewareFunc func(next HandlerFunc) HandlerFunc

/*
ServerMiddlewareChain will attatch all given middlewares to your HandlerFunc.
The middlewares will be executed in the same order as your input.

For example:

    s := New("url")

    s.Bind(DirectBinding(
        "foobar",
        ServerMiddlewareChain(
            myHandler,
            middlewareOne,
            middlewareTwo,
            middlewareThree,
        ),
    ))
*/
func ServerMiddlewareChain(next HandlerFunc, m ...ServerMiddlewareFunc) HandlerFunc {
    if len(m) == 0 {
        // The middleware chain is done. All middlewares have been applied.
        return next
    }

    // Nest the middlewares so that we attatch them in order.
    // The first middleware will have the second middleware applied, and so on.
    return m[0](ServerMiddlewareChain(next, m[1:]...))
}