如何将我的AppHandler添加到路线中？

Question

I am trying to implement an appHandler as described in The Go Blog: Error handling and Go. I have the appHandler, now I'm just trying to hook it up to my routes. The following works:

router := new(mux.Router)
router.Handle("/my/route/", handlers.AppHandler(handlers.MyRoute))

But, I want to be able to allow GET requests as well as having "StrictSlash(true)". I have:

type Routes []Route
type Route struct {
    Method      string
    Pattern     string
    HandlerFunc http.HandlerFunc
}


var routes = Routes{
    Route{"GET", "/my/route/", handlers.AppHandler(handlers.MyRoute)}
} 
router := mux.NewRouter().StrictSlash(true)
for _, route := range routes {
    var handler http.Handler
    handler = route.HandlerFunc
    router.Methods(route.Method).Path(route.Pattern).Handler(handler)
}

AppHandler looks like:

type AppHandler func(http.ResponseWriter, *http.Request) *appError

func (fn AppHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    // blah, blah, blah
}

I get an error:

cannot use handlers.AppHandler(handlers.MyRoute) (type handlers.AppHandler) as type http.HandlerFunc in field value

Answer 1

Your AppHandler isn't a http.HandlerFunc, it's a http.Handler.

A http.HandlerFunc is just a function that takes both a http.ResponseWriter and a *http.Request.

http.Handler is an interface that is satisfied by any type that has a method ServeHTTP(w http.ResponseWriter, r *http.Request)

Change your struct to something like

type Route struct {
    Method  string
    Pattern string
    Handler http.Handler
}

And then at the bottom you can probably do

for _, route := range routes {
    router.Methods(route.Method).Path(route.Pattern).Handler(route.Handler)
}