Add ConstructorFunc / MiddlewareFunc

[jgraettinger]

MiddlewareFunc defines a standard signature for a http.HandlerFunc which
accepts a chained http.Handler to invoke. ConstructorFunc supplies an
adapter for converting a MiddlewareFunc into a Constructor. This is most
useful for building middleware with bound parameters via closures.

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This change is

[jgraettinger]

Adding a test case is a TODO, but I'd first appreciate confirmation that the idea is acceptable.

[ravisastryk]

Review status: 0 of 1 files reviewed at latest revision, 1 unresolved discussion.

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chain.go, line 33 [r1] (raw file):

      f(w, r, next)
  }
  return http.HandlerFunc(h)

Just a code beautification, avoid 'var h' and use anonymous function call directly. Consider 'return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
f(w, r, next)
})

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Comments from Reviewable

[jgraettinger]

Apologies for the delay. Reviewing the tests, switching over tagMiddlware appeared as a concise way to add coverage on ConstructorFunc without sacrificing coverage elsewhere, and that's what I've done here. Let me know your thoughts.

PTAL.

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Review status: 0 of 2 files reviewed at latest revision, 1 unresolved discussion.

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chain.go, line 33 [r1] (raw file):

Previously, ravisastryk wrote…

Just a code beautification, avoid 'var h' and use anonymous function call directly. Consider 'return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
f(w, r, next)
})

Done.

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Comments from Reviewable

[jgraettinger]

Bueller ?

[sb89]

+1

[Akagi201]

+1

[justinas]

Sorry for the delay and I hate to be bikeshedding at this point, but one thing I'd like to do with this is clear separation of this model of middleware as an "adapter".

As the naming stands now, ConstructorFunc seems to be to Constructor as what HandlerFunc is to Handler, which is incorrect. What I'd like to know is:

• Is there an established name for this middleware pattern? 'Negroni-like'..?
• What would you think about moving it into a subpackage (.../alice/something)?
• What would a better name for ConstructorFunc be?

[Akagi201]

Look at https://godoc.org/github.com/go-web/httpmux#Middleware and https://godoc.org/github.com/go-web/httpmux#MiddlewareFunc. And github search here: https://github.com/search?utf8=%E2%9C%93&q=MiddlewareFunc+language%3Ago&type=Code&ref=searchresults

I think better names are MiddlewareFunc and Middleware, but it wil not be backwards compatibile.