Add gin example

examples/gin/main.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"github.com/markbates/goth/providers/twitter"
+	"html/template"
+	"net/http"
+	"os"
+
+	"sort"
+
+	"log"
+
+	"github.com/gin-gonic/gin"
+	"github.com/markbates/goth"
+	"github.com/markbates/goth/gothic"
+)
+
+func main() {
+	goth.UseProviders(
+		twitter.New(os.Getenv("TWITTER_KEY"), os.Getenv("TWITTER_SECRET"), "http://localhost:3000/auth/twitter/callback"),
+	)
+
+	m := make(map[string]string)
+	m["twitter"] = "Twitter"
+
+	var keys []string
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	providerIndex := &ProviderIndex{Providers: keys, ProvidersMap: m}
+
+	r := gin.Default()
+
+	r.GET("/auth/:provider/callback", func(c *gin.Context) {
+		provider := c.Param("provider")
+
+		// You have to add value context with provider name to get provider name in GetProviderName method
+		c.Request = contextWithProviderName(c, provider)
+
+		user, err := gothic.CompleteUserAuth(c.Writer, c.Request)
+		if err != nil {
+			fmt.Fprintln(c.Writer, err)
+			return
+		}
+		t, _ := template.New("foo").Parse(userTemplate)
+		t.Execute(c.Writer, user)
+	})
+
+	r.GET("/logout/:provider", func(c *gin.Context) {
+		gothic.Logout(c.Writer, c.Request)
+		c.Redirect(http.StatusTemporaryRedirect, "/")
+	})
+
+	r.GET("/auth/:provider", func(c *gin.Context) {
+		provider := c.Param("provider")
+
+		// You have to add value context with provider name to get provider name in GetProviderName method
+		c.Request = contextWithProviderName(c, provider)
+
+		// try to get the user without re-authenticating
+		if gothUser, err := gothic.CompleteUserAuth(c.Writer, c.Request); err == nil {
+			t, _ := template.New("foo").Parse(userTemplate)
+			t.Execute(c.Writer, gothUser)
+		} else {
+			gothic.BeginAuthHandler(c.Writer, c.Request)
+		}
+	})
+
+	r.GET("/", func(c *gin.Context) {
+		t, _ := template.New("foo").Parse(indexTemplate)
+		t.Execute(c.Writer, providerIndex)
+	})
+
+	log.Fatal(r.Run(":3000"))
+}
+
+func contextWithProviderName(c *gin.Context, provider string) (*http.Request){
+	return	c.Request.WithContext(context.WithValue(c.Request.Context(), "provider", provider))
+}
+
+type ProviderIndex struct {
+	Providers    []string
+	ProvidersMap map[string]string
+}
+
+var indexTemplate = `{{range $key,$value:=.Providers}}
+    <p><a href="/auth/{{$value}}">Log in with {{index $.ProvidersMap $value}}</a></p>
+{{end}}`
+
+var userTemplate = `
+<p><a href="/logout/{{.Provider}}">logout</a></p>
+<p>Name: {{.Name}} [{{.LastName}}, {{.FirstName}}]</p>
+<p>Email: {{.Email}}</p>
+<p>NickName: {{.NickName}}</p>
+<p>Location: {{.Location}}</p>
+<p>AvatarURL: {{.AvatarURL}} <img src="{{.AvatarURL}}"></p>
+<p>Description: {{.Description}}</p>
+<p>UserID: {{.UserID}}</p>
+<p>AccessToken: {{.AccessToken}}</p>
+<p>ExpiresAt: {{.ExpiresAt}}</p>
+<p>RefreshToken: {{.RefreshToken}}</p>
+`