add example: dependency-injection/jwt

Former-commit-id: 77cdc7fa5f8a656857a3912910e037806adf70a9

_examples/dependency-injection/jwt/main.go

@@ -0,0 +1,63 @@
+package main
+
+import (
+	"github.com/kataras/iris/v12"
+
+	"github.com/iris-contrib/middleware/jwt"
+)
+
+var secret = []byte("My Secret Key")
+
+func main() {
+	app := iris.New()
+	app.ConfigureContainer(register)
+
+	app.Listen(":8080")
+}
+
+func register(api *iris.APIContainer) {
+	j := jwt.New(jwt.Config{
+		// Extract by "token" url parameter.
+		Extractor: jwt.FromFirst(jwt.FromParameter("token"), jwt.FromAuthHeader),
+		ValidationKeyGetter: func(token *jwt.Token) (interface{}, error) {
+			return secret, nil
+		},
+		SigningMethod: jwt.SigningMethodHS256,
+	})
+
+	api.Get("/token", writeToken)
+	// This works as usually:
+	api.Get("/", j.Serve, verifiedPage)
+
+	// You can also bind the *jwt.Token (see `verifiedWithBindedTokenPage`)
+	// by registering a *jwt.Token dependency.
+	//
+	// api.RegisterDependency(func(ctx iris.Context) *jwt.Token {
+	// 	if err := j.CheckJWT(ctx); err != nil {
+	// 		ctx.StopWithStatus(iris.StatusUnauthorized)
+	// 		return nil
+	// 	}
+
+	// 	token := j.Get(ctx)
+	// 	return token
+	// })
+	// api.Get("/", verifiedWithBindedTokenPage)
+}
+
+func writeToken() string {
+	token := jwt.NewTokenWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
+		"foo": "bar",
+	})
+
+	tokenString, _ := token.SignedString(secret)
+	return tokenString
+}
+
+func verifiedPage() string {
+	return "This page can only be seen by verified clients"
+}
+
+func verifiedWithBindedTokenPage(token *jwt.Token) string {
+	// Token[foo] value: bar
+	return "Token[foo] value: " + token.Claims.(jwt.MapClaims)["foo"].(string)
+}