diff options
Diffstat (limited to 'src/vendor/github.com/justinas/alice/chain.go')
| -rw-r--r-- | src/vendor/github.com/justinas/alice/chain.go | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/src/vendor/github.com/justinas/alice/chain.go b/src/vendor/github.com/justinas/alice/chain.go deleted file mode 100644 index d281ad3..0000000 --- a/src/vendor/github.com/justinas/alice/chain.go +++ /dev/null @@ -1,119 +0,0 @@ -// Package alice provides a convenient way to chain http handlers. -package alice - -import "net/http" - -// A constructor for a piece of middleware. -// Some middleware use this constructor out of the box, -// so in most cases you can just pass somepackage.New -type Constructor func(http.Handler) http.Handler - -// Chain acts as a list of http.Handler constructors. -// Chain is effectively immutable: -// once created, it will always hold -// the same set of constructors in the same order. -type Chain struct { - constructors []Constructor -} - -// New creates a new chain, -// memorizing the given list of middleware constructors. -// New serves no other function, -// constructors are only called upon a call to Then(). -func New(constructors ...Constructor) Chain { - c := Chain{} - c.constructors = append(c.constructors, constructors...) - - return c -} - -// Then chains the middleware and returns the final http.Handler. -// New(m1, m2, m3).Then(h) -// is equivalent to: -// m1(m2(m3(h))) -// When the request comes in, it will be passed to m1, then m2, then m3 -// and finally, the given handler -// (assuming every middleware calls the following one). -// -// A chain can be safely reused by calling Then() several times. -// stdStack := alice.New(ratelimitHandler, csrfHandler) -// indexPipe = stdStack.Then(indexHandler) -// authPipe = stdStack.Then(authHandler) -// Note that constructors are called on every call to Then() -// and thus several instances of the same middleware will be created -// when a chain is reused in this way. -// For proper middleware, this should cause no problems. -// -// Then() treats nil as http.DefaultServeMux. -func (c Chain) Then(h http.Handler) http.Handler { - var final http.Handler - if h != nil { - final = h - } else { - final = http.DefaultServeMux - } - - for i := len(c.constructors) - 1; i >= 0; i-- { - final = c.constructors[i](final) - } - - return final -} - -// ThenFunc works identically to Then, but takes -// a HandlerFunc instead of a Handler. -// -// The following two statements are equivalent: -// c.Then(http.HandlerFunc(fn)) -// c.ThenFunc(fn) -// -// ThenFunc provides all the guarantees of Then. -func (c Chain) ThenFunc(fn http.HandlerFunc) http.Handler { - if fn == nil { - return c.Then(nil) - } - return c.Then(http.HandlerFunc(fn)) -} - -// Append extends a chain, adding the specified constructors -// as the last ones in the request flow. -// -// Append returns a new chain, leaving the original one untouched. -// -// stdChain := alice.New(m1, m2) -// extChain := stdChain.Append(m3, m4) -// // requests in stdChain go m1 -> m2 -// // requests in extChain go m1 -> m2 -> m3 -> m4 -func (c Chain) Append(constructors ...Constructor) Chain { - newCons := make([]Constructor, len(c.constructors)+len(constructors)) - copy(newCons, c.constructors) - copy(newCons[len(c.constructors):], constructors) - - newChain := New(newCons...) - return newChain -} - -// Extend extends a chain by adding the specified chain -// as the last one in the request flow. -// -// Extend returns a new chain, leaving the original one untouched. -// -// stdChain := alice.New(m1, m2) -// ext1Chain := alice.New(m3, m4) -// ext2Chain := stdChain.Extend(ext1Chain) -// // requests in stdChain go m1 -> m2 -// // requests in ext1Chain go m3 -> m4 -// // requests in ext2Chain go m1 -> m2 -> m3 -> m4 -// -// Another example: -// aHtmlAfterNosurf := alice.New(m2) -// aHtml := alice.New(m1, func(h http.Handler) http.Handler { -// csrf := nosurf.New(h) -// csrf.SetFailureHandler(aHtmlAfterNosurf.ThenFunc(csrfFail)) -// return csrf -// }).Extend(aHtmlAfterNosurf) -// // requests to aHtml hitting nosurfs success handler go m1 -> nosurf -> m2 -> target-handler -// // requests to aHtml hitting nosurfs failure handler go m1 -> nosurf -> m2 -> csrfFail -func (c Chain) Extend(chain Chain) Chain { - return c.Append(chain.constructors...) -} |
