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Diffstat (limited to 'vendor/github.com/gorilla/context/doc.go')
-rw-r--r-- | vendor/github.com/gorilla/context/doc.go | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/vendor/github.com/gorilla/context/doc.go b/vendor/github.com/gorilla/context/doc.go new file mode 100644 index 000000000..73c740031 --- /dev/null +++ b/vendor/github.com/gorilla/context/doc.go @@ -0,0 +1,82 @@ +// Copyright 2012 The Gorilla Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* +Package context stores values shared during a request lifetime. + +For example, a router can set variables extracted from the URL and later +application handlers can access those values, or it can be used to store +sessions values to be saved at the end of a request. There are several +others common uses. + +The idea was posted by Brad Fitzpatrick to the go-nuts mailing list: + + http://groups.google.com/group/golang-nuts/msg/e2d679d303aa5d53 + +Here's the basic usage: first define the keys that you will need. The key +type is interface{} so a key can be of any type that supports equality. +Here we define a key using a custom int type to avoid name collisions: + + package foo + + import ( + "github.com/gorilla/context" + ) + + type key int + + const MyKey key = 0 + +Then set a variable. Variables are bound to an http.Request object, so you +need a request instance to set a value: + + context.Set(r, MyKey, "bar") + +The application can later access the variable using the same key you provided: + + func MyHandler(w http.ResponseWriter, r *http.Request) { + // val is "bar". + val := context.Get(r, foo.MyKey) + + // returns ("bar", true) + val, ok := context.GetOk(r, foo.MyKey) + // ... + } + +And that's all about the basic usage. We discuss some other ideas below. + +Any type can be stored in the context. To enforce a given type, make the key +private and wrap Get() and Set() to accept and return values of a specific +type: + + type key int + + const mykey key = 0 + + // GetMyKey returns a value for this package from the request values. + func GetMyKey(r *http.Request) SomeType { + if rv := context.Get(r, mykey); rv != nil { + return rv.(SomeType) + } + return nil + } + + // SetMyKey sets a value for this package in the request values. + func SetMyKey(r *http.Request, val SomeType) { + context.Set(r, mykey, val) + } + +Variables must be cleared at the end of a request, to remove all values +that were stored. This can be done in an http.Handler, after a request was +served. Just call Clear() passing the request: + + context.Clear(r) + +...or use ClearHandler(), which conveniently wraps an http.Handler to clear +variables at the end of a request lifetime. + +The Routers from the packages gorilla/mux and gorilla/pat call Clear() +so if you are using either of them you don't need to clear the context manually. +*/ +package context |