working on flash messages

cookies/cookies.go

@@ -0,0 +1,109 @@
+package cookies
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"net/http"
+	"time"
+
+	"github.com/gorilla/securecookie"
+)
+
+const flashCookieName = "tuukoti_flash"
+
+type Cookies struct {
+	secureCookies *securecookie.SecureCookie
+}
+
+func New(sc *securecookie.SecureCookie) *Cookies {
+	return &Cookies{secureCookies: sc}
+}
+
+func (c *Cookies) Create(name string, val string) (*http.Cookie, error) {
+	encodedValue, err := c.secureCookies.Encode(name, val)
+	if err != nil {
+		return nil, err
+	}
+
+	cookie := &http.Cookie{
+		Name:     name,
+		Value:    encodedValue,
+		Expires:  time.Now().Add(3 * (24 * time.Hour)),
+		HttpOnly: true,
+		Path:     "/",
+	}
+
+	return cookie, nil
+}
+
+// ReadCookie will decode the secure cookie value into `out`.
+func (c *Cookies) Read(req *http.Request, name string, out interface{}) error {
+	cookie, err := req.Cookie(name)
+	if err != nil {
+		return err
+	}
+
+	return c.secureCookies.Decode(name, cookie.Value, out)
+}
+
+// SetFlashCookie will set a flash cookie with the data you give it a map[string]string{}.
+func SetFlash(w http.ResponseWriter, val map[string]string) error {
+	b, err := json.Marshal(val)
+	if err != nil {
+		return err
+	}
+
+	co := &http.Cookie{
+		Name:     flashCookieName,
+		Value:    encode(b),
+		Path:     "/",
+		HttpOnly: true,
+	}
+
+	http.SetCookie(w, co)
+
+	return nil
+}
+
+// GetFlash will return any flash data as a map[string]string{}.
+// It also sets the flash cookies value back to nothing so the flash only exists once.
+func GetFlash(w http.ResponseWriter, req *http.Request) (map[string]string, error) {
+	co, err := req.Cookie(flashCookieName)
+	if err != nil {
+		switch err {
+		case http.ErrNoCookie:
+			return nil, nil
+		default:
+			return nil, err
+		}
+	}
+
+	value, err := decode(co.Value)
+	if err != nil {
+		return nil, err
+	}
+
+	out := map[string]string{}
+	if err := json.Unmarshal(value, &out); err != nil {
+		return nil, err
+	}
+
+	http.SetCookie(w, &http.Cookie{
+		Name:     flashCookieName,
+		Value:    "",
+		MaxAge:   -1,
+		Expires:  time.Unix(1, 0),
+		Path:     "/",
+		HttpOnly: true,
+	})
+
+	return out, nil
+}
+
+func encode(src []byte) string {
+	return base64.URLEncoding.EncodeToString(src)
+}
+
+func decode(src string) ([]byte, error) {
+	return base64.URLEncoding.DecodeString(src)
+}