URL encoded parameters not working

[philicious]

if you have sth like
Router.HandleFunc("/bla/{foo}", someHandler)

the "foo" parameter cant be an URL-encoded string like "hmm%2Fstrange"

[vip8439]

I'm having the same issue. Did you figure out a workaround?

[philicious]

@vip8439 no I didnt. I used a POST request instead and put the URL in the POST data

[vip8439]

@philicious I ended up using query parameters instead. My co-worker found (https://golang.org/pkg/net/url/#URL). See the last part of URL. The issue is probably related to that and not gorilla mux itself. If I get the time I'll look at the gorilla mux source and verify whether it's using that.

[gulyasm]

I believe this is definietly the reason.
https://github.com/gorilla/mux/blob/master/route.go#L466-L483

I don't see any obvious fix, I'll try to look into it tomorrow. For now, moving the parameter after the ? as a GET parameter solves the issue.

[echlebek]

I think @vip8439 is correct. See http://play.golang.org/p/syfazuTMbV

Also see golang/go#7356.

It seems to me that gorilla is doing the right thing here.

[echlebek]

Actually, I guess it's not doing the right thing since it ends up responding with 301 instead of 404. So that should probably be fixed.

[gulyasm]

I will try to fix this next week or the one after that. But I am a little confused what the correct behaviour should be. Returning 404 is obvious, but the URL should be resolved correctly or this is something we can't / shouldn't change? I'm still not convinced by golang/go#7356 that this is the correct way of handling the Path parameters. Ideas? @kisielk ?

[rogierlommers]

Same problem here; indeed a bug of the net/url package. I tried to implement a workaround: not using urlencoded data, but base64 strings. Unfortunately this does not work for me. I have created an issue for this: #96

[echlebek]

Are you using base64 encoded strings or base64url encoded strings? You
cannot use base64 as it includes '/' in its charset.

On Monday, May 18, 2015, Rogier Lommers notifications@github.com wrote:

Same problem here; indeed a bug of the net/url package. I tried to
implement a workaround: not using urlencoded data, but base64 strings.
Unfortunately this does not work for me. I have created an issue for this:

—
Reply to this email directly or view it on GitHub
#77 (comment).

[rogierlommers]

Well, my source string is var url="https://www.youtube.com/watch?v=TmiK9skef3s". I need a way to pass this string to my Go program as a parameter. r.HandleFunc("/add/{value}". I have tried several ways to encode the string through JavaScript (I need to do this through JavaScript, because it's done through a bookmarklet).

urlEscaped(url): https%3A//www.youtube.com/watch%3Fv%3DTmiK9skef3s

encodeURIComponent(url): https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DTmiK9skef3s

btoa(url): aHR0cHM6Ly93d3cueW91dHViZS5jb20vd2F0Y2g/dj1UbWlLOXNrZWYzcw==

Now what is the safest way to encode the string so I can decode it in Golang (and how?)

[garyburd]

In Javascript, encode the value with encodeURIComponent and pass it as a query parameter.

In the Go code, call req.FormValue("parameterName") to get the decoded value.

Passing encoded values as a path element is tricky because of the design error in the net/url package. It's simpler to use query parameters.

[rogierlommers]

Thanks; working fine with query parameters, instead of path parameters.

[derekdowling]

I'm running Go 1.5.1 which claims to have been the issue here #77 (comment) and I am still seeing this issue.

Example:

    // router build
    router = mux.NewRouter()
    router.HandleFunc("/status", status).Methods("GET")

    apiRouter := mux.NewRouter()
    apiRouter.HandleFunc("/foo", getFooList).Methods("GET")
    apiRouter.HandleFunc("/foo/{bar}", getFoo).Methods("GET")

    router.PathPrefix("/foo").Handler(negroni.New(
        OAuthRequired(config.OAuth),
        negroni.Wrap(apiRouter),
    ))

    url := httptest.NewServer(router).URL
    url1 := strings.Join([]string{url, "/foo/bar%2ftest"}, "")
    // url2 := strings.Join([]string{url, "/foo/bar.test}", "")

    req, err := http.NewRequest("GET", url1, nil)

    client := &http.Client{}
    req, err := client.Do(req)
    fmt.Printf("Req: %+v \n Err: %+v \n", req, err)

If I use url1 I get a 404, if I use url2 I get a 200. Thoughts? I am using Ember-Data to generate API calls so short of performing a huge hack on both ends, I need this to work properly, or alternatively to find a new router.

[highway900]

Sorry to bring this up again. But this is still a bug. @garyburd can you explain this a little more? "Passing encoded values as a path element is tricky because of the design error in the net/url package. It's simpler to use query parameters."

[garyburd]

@highway900 Unescaping a path to a string is a lossy operation.

A specific example is that it's not possible to distinguish a "/" in a path element from a "/" used as a path element separator. A workaround was added in 0a192a1 and updated in c9183aa.

[tulov]

if you have sth like
Router.HandleFunc("/bla/{foo}", someHandler)

the "foo" parameter cant be an URL-encoded string like "hmm%2Fstrange"

I solved this problem like this:
Router.HandleFunc("/bla/{foo:.+}", someHandler)

This only works if the parameter goes last.

[suibh]

Can also use

router = mux.NewRouter().UseEncodedPath()

Have to then use url.QueryUnescape in the route

[d681]

url.QueryUnescape doesn't seem to work either ;(.

[elithrar]

@d681 - please open a new issue with your example, as "doesn't seem to work" doesn't help us help you :)

[d681]

Turns out I had an outdated version of Gorilla mux. Updating the package made it work. Thanks and sorry for the bother.