Feature request: GetAuthorizedURL on Object about blazer

[kurin]

I wish I knew how often people just wanted to share one object vs wanting an auth token for a common prefix of many objects.

What about something like

type Token string

func (t Token) URL(o *Object) (*url.URL, error)

so that getting auth tokens is still essentially a bucket operation, but has a convenience method for individual objects.

[kennylevinsen]

I can't really come up with a real use-case for issuing a token for a prefix of many objects, instead of just using a token per object, but that may of course just be because I am a bit too focused on the use-cases I have experienced myself.

That interface would seem slightly quirky. First of all, it's a bit repetitive:

token, _ := bucket.AuthToken(ctx, objectName, validity)
obj := bucket.Object(objectName)
url, _ := token.URL(obj)

Second, it would blindly generate URL's for objects that the token is incapable of serving, making it a bit error-prone. In case of b2ContentDisposition, the token will be even more limited in use (which I unfortunately need...).

I personally like the idea of having automatic token issue on Object convenience methods better, as it is both more convenient and more robust. I won't cry myself to sleep if that doesn't happen, though. :)

[kurin]

I'm interested in avoiding API bloat, but I think you're right that your use case is probably fairly common, enough so to warrant these helpers.

I would like to avoid two different methods though. I'm starting to worry that I'm overusing the ThingOption pattern a little bit, but it could apply here. Alternatively we could just leave that argument empty for no b2ContentDisposition argument.

[kurin]

B2 doesn't have any documentation that I've found specifying how many auth tokens you're able to get. (You also apparently can't revoke them once you have them.) So I guess it could just generate a new token each time.

[kurin]

Take a look at that PR and see if it's something that would fit your use case.

It requests a new token for every call to AuthURL(), which I figure if people want to cache it they can probably do that themselves.

[kennylevinsen]

I haven't tested it, but that PR fits my use-case perfectly, and in the most convenient way it could be done, so I couldn't be happier!

I would have commented that you should add a few url.QueryEscape calls, but you beat me to it.