Actually, Goji grew out of a single deficiency in "pat": the fact that it does not have a standard way of defining request context.
The big use case here is how you'd write a middleware that did authentication (using API keys, session cookies, ???) and emitted a username for other middleware to consume. With net/http, you end up with a lot of coupling: your end handler needs to know about every layer of middleware above it, and you start losing a lot of the benefit of having middleware in the first place. With an explicit middleware stack and a universal interface for middleware contexts, this is easy: everyone can code to the same single context object, and instead of standardizing on weird bound variables (or a global locked map a la gorilla), you just need to standardize on a single string key and a type.
I think my ideal world would involve Go providing a map[string]interface{} as part of the http.Request struct in order to implement this behavior, but until we get that, I think Goji's web.C ("the context object") is the next best thing.
There's one other thing pat hacks around: the issue of how to pass bound URL variables to the resulting handler. At first I was a little grossed out at how pat did it, but I've sort of come to terms with it. I still think Goji's way is better, but I don't think it's the reason I wrote (or a reason to use) Goji.
The big use case here is how you'd write a middleware that did authentication (using API keys, session cookies, ???) and emitted a username for other middleware to consume. With net/http, you end up with a lot of coupling: your end handler needs to know about every layer of middleware above it, and you start losing a lot of the benefit of having middleware in the first place. With an explicit middleware stack and a universal interface for middleware contexts, this is easy: everyone can code to the same single context object, and instead of standardizing on weird bound variables (or a global locked map a la gorilla), you just need to standardize on a single string key and a type.
I think my ideal world would involve Go providing a map[string]interface{} as part of the http.Request struct in order to implement this behavior, but until we get that, I think Goji's web.C ("the context object") is the next best thing.
There's one other thing pat hacks around: the issue of how to pass bound URL variables to the resulting handler. At first I was a little grossed out at how pat did it, but I've sort of come to terms with it. I still think Goji's way is better, but I don't think it's the reason I wrote (or a reason to use) Goji.