diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/rs/xhandler/chain.go')
-rw-r--r-- | Godeps/_workspace/src/github.com/rs/xhandler/chain.go | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/rs/xhandler/chain.go b/Godeps/_workspace/src/github.com/rs/xhandler/chain.go new file mode 100644 index 000000000..ffac67e8a --- /dev/null +++ b/Godeps/_workspace/src/github.com/rs/xhandler/chain.go @@ -0,0 +1,93 @@ +package xhandler + +import ( + "net/http" + + "github.com/ethereum/go-ethereum/Godeps/_workspace/src/golang.org/x/net/context" +) + +// Chain is an helper to chain middleware handlers together for an easier +// management. +type Chain []func(next HandlerC) HandlerC + +// UseC appends a context-aware handler to the middleware chain. +func (c *Chain) UseC(f func(next HandlerC) HandlerC) { + *c = append(*c, f) +} + +// Use appends a standard http.Handler to the middleware chain without +// lossing track of the context when inserted between two context aware handlers. +// +// Caveat: the f function will be called on each request so you are better to put +// any initialization sequence outside of this function. +func (c *Chain) Use(f func(next http.Handler) http.Handler) { + xf := func(next HandlerC) HandlerC { + return HandlerFuncC(func(ctx context.Context, w http.ResponseWriter, r *http.Request) { + n := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + next.ServeHTTPC(ctx, w, r) + }) + f(n).ServeHTTP(w, r) + }) + } + *c = append(*c, xf) +} + +// Handler wraps the provided final handler with all the middleware appended to +// the chain and return a new standard http.Handler instance. +// The context.Background() context is injected automatically. +func (c Chain) Handler(xh HandlerC) http.Handler { + ctx := context.Background() + return c.HandlerCtx(ctx, xh) +} + +// HandlerFC is an helper to provide a function (HandlerFuncC) to Handler(). +// +// HandlerFC is equivalent to: +// c.Handler(xhandler.HandlerFuncC(xhc)) +func (c Chain) HandlerFC(xhf HandlerFuncC) http.Handler { + ctx := context.Background() + return c.HandlerCtx(ctx, HandlerFuncC(xhf)) +} + +// HandlerH is an helper to provide a standard http handler (http.HandlerFunc) +// to Handler(). Your final handler won't have access the context though. +func (c Chain) HandlerH(h http.Handler) http.Handler { + ctx := context.Background() + return c.HandlerCtx(ctx, HandlerFuncC(func(ctx context.Context, w http.ResponseWriter, r *http.Request) { + h.ServeHTTP(w, r) + })) +} + +// HandlerF is an helper to provide a standard http handler function +// (http.HandlerFunc) to Handler(). Your final handler won't have access +// the context though. +func (c Chain) HandlerF(hf http.HandlerFunc) http.Handler { + ctx := context.Background() + return c.HandlerCtx(ctx, HandlerFuncC(func(ctx context.Context, w http.ResponseWriter, r *http.Request) { + hf(w, r) + })) +} + +// HandlerCtx wraps the provided final handler with all the middleware appended to +// the chain and return a new standard http.Handler instance. +func (c Chain) HandlerCtx(ctx context.Context, xh HandlerC) http.Handler { + return New(ctx, c.HandlerC(xh)) +} + +// HandlerC wraps the provided final handler with all the middleware appended to +// the chain and returns a HandlerC instance. +func (c Chain) HandlerC(xh HandlerC) HandlerC { + for i := len(c) - 1; i >= 0; i-- { + xh = c[i](xh) + } + return xh +} + +// HandlerCF wraps the provided final handler func with all the middleware appended to +// the chain and returns a HandlerC instance. +// +// HandlerCF is equivalent to: +// c.HandlerC(xhandler.HandlerFuncC(xhc)) +func (c Chain) HandlerCF(xhc HandlerFuncC) HandlerC { + return c.HandlerC(HandlerFuncC(xhc)) +} |