Add use examples

Author: LyricTian

example/README.md

@@ -1,8 +1,4 @@
-# Authorization Code Grant
-
-![login](https://raw.githubusercontent.com/go-oauth2/oauth2/master/example/server/static/login.png)
-![auth](https://raw.githubusercontent.com/go-oauth2/oauth2/master/example/server/static/auth.png)
-![token](https://raw.githubusercontent.com/go-oauth2/oauth2/master/example/server/static/token.png)
+# Use Examples
 
 ## Run Server
 
@@ -20,7 +16,9 @@ $ go build client.go
 $ ./client
 ```
 
-## Open the browser
+## Authorization Code Grant
+
+### Open the browser
 
 [http://localhost:9094](http://localhost:9094)
 
@@ -34,7 +32,7 @@ $ ./client
 ```
 
 
-## Try access token
+### Try access token
 
 Open the browser [http://localhost:9094/try](http://localhost:9094/try)
 
@@ -57,4 +55,33 @@ Open the browser [http://localhost:9094/refresh](http://localhost:9094/refresh)
   "refresh_token": "AG6-63MLXUEFUV2Q_BLYIW",
   "expiry": "2019-01-09T23:03:16.374062+08:00"
 }
-```
+```
+
+## Password Credentials Grant
+
+Open the browser [http://localhost:9094/pwd](http://localhost:9094/pwd)
+
+```
+{
+  "access_token": "87JT3N6WOWANXVDNZFHY7Q",
+  "token_type": "Bearer",
+  "refresh_token": "LDIS6PXAVY-BXHPEDESWNG",
+  "expiry": "2019-02-12T10:58:43.734902+08:00"
+}
+```
+
+## Client Credentials Grant
+
+Open the browser [http://localhost:9094/client](http://localhost:9094/client)
+
+```
+{
+  "access_token": "OA6ITALNMDOGD58C0SN-MG",
+  "token_type": "Bearer",
+  "expiry": "2019-02-12T11:10:35.864838+08:00"
+}
+```
+
+![login](https://raw.githubusercontent.com/go-oauth2/oauth2/master/example/server/static/login.png)
+![auth](https://raw.githubusercontent.com/go-oauth2/oauth2/master/example/server/static/auth.png)
+![token](https://raw.githubusercontent.com/go-oauth2/oauth2/master/example/server/static/token.png)

example/client/client.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/clientcredentials"
 )
 
 const (
@@ -95,6 +96,37 @@ func main() {
 		io.Copy(w, resp.Body)
 	})
 
+	http.HandleFunc("/pwd", func(w http.ResponseWriter, r *http.Request) {
+		token, err := config.PasswordCredentialsToken(context.Background(), "test", "test")
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		globalToken = token
+		e := json.NewEncoder(w)
+		e.SetIndent("", "  ")
+		e.Encode(token)
+	})
+
+	http.HandleFunc("/client", func(w http.ResponseWriter, r *http.Request) {
+		cfg := clientcredentials.Config{
+			ClientID:     config.ClientID,
+			ClientSecret: config.ClientSecret,
+			TokenURL:     config.Endpoint.TokenURL,
+		}
+
+		token, err := cfg.Token(context.Background())
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		e := json.NewEncoder(w)
+		e.SetIndent("", "  ")
+		e.Encode(token)
+	})
+
 	log.Println("Client is running at 9094 port.")
 	log.Fatal(http.ListenAndServe(":9094", nil))
 }

example/server/server.go

@@ -32,6 +32,12 @@ func main() {
 	manager.MapClientStorage(clientStore)
 
 	srv := server.NewServer(server.NewConfig(), manager)
+	srv.SetPasswordAuthorizationHandler(func(username, password string) (userID string, err error) {
+		if username == "test" && password == "test" {
+			userID = "test"
+		}
+		return
+	})
 	srv.SetUserAuthorizationHandler(userAuthorizeHandler)
 
 	srv.SetInternalErrorHandler(func(err error) (re *errors.Response) {