Introducing flash messages and i18n support

config/config.go

@@ -21,6 +21,10 @@ type ConfigT struct {
 	Url    string
 	Domain string
 
+	// Language
+
+	Language string
+
 	// Logging
 
 	LogLevel int `yaml:"log_level"`

handlers/handlers.go

@@ -180,7 +180,7 @@ func get(w http.ResponseWriter, r *http.Request, model string, pattern PathPatte
 		log.Println("Error:", err)
 		respondWithError(w, r, err)
 	} else {
-		data, err := getFn(mux.Vars(r), r)
+		data, err := getFn(mux.Vars(r), w, r)
 		if err != nil {
 			renderer.Render[format](w, r, err)
 		} else {
@@ -202,7 +202,7 @@ func post(w http.ResponseWriter, r *http.Request, model string, pattern PathPatt
 	if err != nil {
 		respondWithError(w, r, err)
 	} else {
-		data, err = postFn(mux.Vars(r), r)
+		data, err = postFn(mux.Vars(r), w, r)
 		if err != nil {
 			respondWithError(w, r, err)
 		} else if pattern.RedirectPattern != "" {
@@ -232,7 +232,7 @@ func delete(w http.ResponseWriter, r *http.Request, model string, pattern PathPa
 	if err != nil {
 		renderer.Render[r.URL.Query().Get("format")](w, r, err)
 	}
-	data, err = postFn(mux.Vars(r), r)
+	data, err = postFn(mux.Vars(r), w, r)
 	if err != nil {
 		renderer.Render["html"](w, r, err)
 	} else if pattern.RedirectPattern != "" {

i18n/i18n.go

@@ -0,0 +1,9 @@
+package i18n
+
+var (
+	FlashMessages = map[string]map[string]string{
+		"participantExists": map[string]string{
+			"it": "Un partecipante con questo codice fiscale è già presente nella base dati!",
+		},
+	}
+)

orm/answer.go

@@ -26,7 +26,7 @@ func (a *Answer) String() string {
 	return a.Text
 }
 
-func (a *Answer) Create(args map[string]string, r *http.Request) (interface{}, error) {
+func (a *Answer) Create(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
 		answer := new(Answer)
 		if err := DB().Find(&answer.AllQuestions).Error; err != nil {
@@ -48,7 +48,7 @@ func (a *Answer) Create(args map[string]string, r *http.Request) (interface{}, e
 	}
 }
 
-func (a *Answer) Read(args map[string]string, r *http.Request) (interface{}, error) {
+func (a *Answer) Read(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var answer Answer
 
 	id := args["id"]
@@ -60,7 +60,7 @@ func (a *Answer) Read(args map[string]string, r *http.Request) (interface{}, err
 	return &answer, nil
 }
 
-func (a *Answer) ReadAll(args map[string]string, r *http.Request) (interface{}, error) {
+func (a *Answer) ReadAll(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var answers []*Answer
 	if err := DB().Preload("Question").Order("created_at").Find(&answers).Error; err != nil {
 		return nil, err
@@ -68,9 +68,9 @@ func (a *Answer) ReadAll(args map[string]string, r *http.Request) (interface{},
 	return answers, nil
 }
 
-func (a *Answer) Update(args map[string]string, r *http.Request) (interface{}, error) {
+func (a *Answer) Update(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
-		result, err := a.Read(args, r)
+		result, err := a.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -86,7 +86,7 @@ func (a *Answer) Update(args map[string]string, r *http.Request) (interface{}, e
 
 		return answer, nil
 	} else {
-		answer, err := a.Read(args, nil)
+		answer, err := a.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -102,7 +102,7 @@ func (a *Answer) Update(args map[string]string, r *http.Request) (interface{}, e
 		if err != nil {
 			return nil, err
 		}
-		answer, err = a.Read(args, nil)
+		answer, err = a.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -110,7 +110,7 @@ func (a *Answer) Update(args map[string]string, r *http.Request) (interface{}, e
 	}
 }
 
-func (a *Answer) Delete(args map[string]string, r *http.Request) (interface{}, error) {
+func (a *Answer) Delete(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	return nil, nil
 }
 

orm/contest.go

@@ -31,7 +31,7 @@ func (c *Contest) String() string {
 	return c.Name
 }
 
-func (c *Contest) Create(args map[string]string, r *http.Request) (interface{}, error) {
+func (c *Contest) Create(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
 		return nil, nil
 	} else {
@@ -69,7 +69,7 @@ func (c *Contest) Create(args map[string]string, r *http.Request) (interface{},
 	}
 }
 
-func (c *Contest) Read(args map[string]string, r *http.Request) (interface{}, error) {
+func (c *Contest) Read(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var contest Contest
 
 	id := args["id"]
@@ -81,7 +81,7 @@ func (c *Contest) Read(args map[string]string, r *http.Request) (interface{}, er
 	return &contest, nil
 }
 
-func (c *Contest) ReadAll(args map[string]string, r *http.Request) (interface{}, error) {
+func (c *Contest) ReadAll(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var contests []*Contest
 
 	claims := r.Context().Value("user").(*jwt.Token).Claims.(jwt.MapClaims)
@@ -103,9 +103,9 @@ func (c *Contest) ReadAll(args map[string]string, r *http.Request) (interface{},
 	}
 }
 
-func (c *Contest) Update(args map[string]string, r *http.Request) (interface{}, error) {
+func (c *Contest) Update(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
-		result, err := c.Read(args, r)
+		result, err := c.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -113,7 +113,7 @@ func (c *Contest) Update(args map[string]string, r *http.Request) (interface{},
 
 		return contest, nil
 	} else {
-		contest, err := c.Read(args, nil)
+		contest, err := c.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -146,7 +146,7 @@ func (c *Contest) Update(args map[string]string, r *http.Request) (interface{},
 		if err != nil {
 			return nil, err
 		}
-		contest, err = c.Read(args, nil)
+		contest, err = c.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -154,7 +154,7 @@ func (c *Contest) Update(args map[string]string, r *http.Request) (interface{},
 	}
 }
 
-func (c *Contest) Delete(args map[string]string, r *http.Request) (interface{}, error) {
+func (c *Contest) Delete(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	return nil, nil
 }
 

orm/orm.go

@@ -7,6 +7,8 @@ import (
 	"reflect"
 	"strings"
 
+	"git.andreafazzi.eu/andrea/oef/config"
+	"github.com/gorilla/sessions"
 	"github.com/jinzhu/gorm"
 	"github.com/jinzhu/inflection"
 
@@ -17,15 +19,16 @@ type IDer interface {
 	GetID() uint
 }
 
-type GetFn func(map[string]string, *http.Request) (interface{}, error)
+type GetFn func(map[string]string, http.ResponseWriter, *http.Request) (interface{}, error)
 
 var (
-	fns    map[string]func(map[string]string, *http.Request) (interface{}, error)
+	fns    map[string]func(map[string]string, http.ResponseWriter, *http.Request) (interface{}, error)
 	currDB *gorm.DB
+	store  = sessions.NewCookieStore([]byte(config.Config.Keys.CookieStoreKey))
 )
 
 func init() {
-	fns = make(map[string]func(map[string]string, *http.Request) (interface{}, error), 0)
+	fns = make(map[string]func(map[string]string, http.ResponseWriter, *http.Request) (interface{}, error), 0)
 }
 
 func New(connection string) (*gorm.DB, error) {
@@ -69,7 +72,7 @@ func MapHandlers(models []interface{}) error {
 			if strings.HasSuffix(p, "/") {
 				joinedPath += "/"
 			}
-			fns[joinedPath] = method.Interface().(func(map[string]string, *http.Request) (interface{}, error))
+			fns[joinedPath] = method.Interface().(func(map[string]string, http.ResponseWriter, *http.Request) (interface{}, error))
 		}
 
 	}
@@ -89,7 +92,7 @@ func GetNothing(args map[string]string) (interface{}, error) {
 	return nil, nil
 }
 
-func PostNothing(args map[string]string, r *http.Request) (IDer, error) {
+func PostNothing(args map[string]string, w http.ResponseWriter, r *http.Request) (IDer, error) {
 	return nil, nil
 }
 

orm/participant.go

@@ -6,7 +6,8 @@ import (
 	"net/http"
 	"strings"
 
-	"git.andreafazzi.eu/andrea/oef/errors"
+	"git.andreafazzi.eu/andrea/oef/config"
+	"git.andreafazzi.eu/andrea/oef/i18n"
 	"git.andreafazzi.eu/andrea/oef/renderer"
 	"github.com/jinzhu/gorm"
 )
@@ -49,16 +50,30 @@ func (model *Participant) String() string {
 	return fmt.Sprintf("%s %s", strings.ToUpper(model.Lastname), strings.Title(strings.ToLower(model.Firstname)))
 }
 
-func (model *Participant) BeforeSave(tx *gorm.DB) error {
+func setFlashMessage(w http.ResponseWriter, r *http.Request, key string) error {
-	users := make([]*User, 0)
+	session, err := store.Get(r, "flash-session")
-	if err := tx.Where("username = ?", model.FiscalCode).Find(&users).Error; err != nil {
+	if err != nil {
 		return err
 	}
-
+	session.AddFlash(i18n.FlashMessages[key][config.Config.Language])
-	if len(users) > 0 {
+	err = session.Save(r, w)
-		return errors.RecordExists
+	if err != nil {
+		return err
 	}
+	return nil
+}
 
+func (model *Participant) exists() (*User, error) {
+	var user User
+	if err := DB().First(&user, &User{Username: model.username()}).Error; err != nil && err != gorm.ErrRecordNotFound {
+		return nil, err
+	} else if err == gorm.ErrRecordNotFound {
+		return nil, nil
+	}
+	return &user, nil
+}
+
+func (model *Participant) BeforeSave(tx *gorm.DB) error {
 	var user User
 	if err := tx.FirstOrCreate(&user, &User{
 		Username: model.username(),
@@ -93,7 +108,7 @@ func (model *Participant) AfterDelete(tx *gorm.DB) error {
 	return nil
 }
 
-func (model *Participant) Create(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Participant) Create(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
 		participant := new(Participant)
 		if err := DB().Find(&participant.AllContests).Error; err != nil {
@@ -107,6 +122,19 @@ func (model *Participant) Create(args map[string]string, r *http.Request) (inter
 			return nil, err
 		}
 
+		if user, err := participant.exists(); err == nil && user != nil {
+			if err := DB().Where("user_id = ?", user.ID).Find(&participant).Error; err != nil {
+				return nil, err
+			}
+			err := setFlashMessage(w, r, "participantExists")
+			if err != nil {
+				return nil, err
+			}
+			return participant, nil
+		} else if err != nil {
+			return nil, err
+		}
+
 		participant, err = CreateParticipant(participant)
 		if err != nil {
 			return nil, err
@@ -115,7 +143,7 @@ func (model *Participant) Create(args map[string]string, r *http.Request) (inter
 	}
 }
 
-func (model *Participant) Read(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Participant) Read(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var participant Participant
 
 	id := args["id"]
@@ -127,7 +155,7 @@ func (model *Participant) Read(args map[string]string, r *http.Request) (interfa
 	return &participant, nil
 }
 
-func (model *Participant) ReadAll(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Participant) ReadAll(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var participants []*Participant
 	if err := DB().Preload("Contests").Preload("Responses").Order("created_at").Find(&participants).Error; err != nil {
 		return nil, err
@@ -135,9 +163,9 @@ func (model *Participant) ReadAll(args map[string]string, r *http.Request) (inte
 	return participants, nil
 }
 
-func (model *Participant) Update(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Participant) Update(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
-		result, err := model.Read(args, r)
+		result, err := model.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -155,7 +183,7 @@ func (model *Participant) Update(args map[string]string, r *http.Request) (inter
 
 		return participant, nil
 	} else {
-		participant, err := model.Read(args, nil)
+		participant, err := model.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -164,6 +192,18 @@ func (model *Participant) Update(args map[string]string, r *http.Request) (inter
 			return nil, err
 		}
 
+		if user, err := participant.(*Participant).exists(); err == nil && user != nil {
+			if user.ID != participant.(*Participant).UserID {
+				err := setFlashMessage(w, r, "participantExists")
+				if err != nil {
+					return nil, err
+				}
+				return participant, nil
+			}
+		} else if err != nil {
+			return nil, err
+		}
+
 		if err := DB().Where(participant.(*Participant).ContestIDs).Find(&participant.(*Participant).Contests).Error; err != nil {
 			return nil, err
 		}
@@ -177,7 +217,7 @@ func (model *Participant) Update(args map[string]string, r *http.Request) (inter
 			return nil, err
 		}
 
-		participant, err = model.Read(args, nil)
+		participant, err = model.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -185,8 +225,8 @@ func (model *Participant) Update(args map[string]string, r *http.Request) (inter
 	}
 }
 
-func (model *Participant) Delete(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Participant) Delete(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
-	participant, err := model.Read(args, nil)
+	participant, err := model.Read(args, w, r)
 	if err != nil {
 		return nil, err
 	}

orm/question.go

@@ -26,7 +26,7 @@ func (q *Question) String() string {
 	return q.Text
 }
 
-func (q *Question) Create(args map[string]string, r *http.Request) (interface{}, error) {
+func (q *Question) Create(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
 		question := new(Question)
 		if err := DB().Find(&question.AllContests).Error; err != nil {
@@ -47,7 +47,7 @@ func (q *Question) Create(args map[string]string, r *http.Request) (interface{},
 	}
 }
 
-func (q *Question) Read(args map[string]string, r *http.Request) (interface{}, error) {
+func (q *Question) Read(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var question Question
 
 	id := args["id"]
@@ -59,7 +59,7 @@ func (q *Question) Read(args map[string]string, r *http.Request) (interface{}, e
 	return &question, nil
 }
 
-func (q *Question) ReadAll(args map[string]string, r *http.Request) (interface{}, error) {
+func (q *Question) ReadAll(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var questions []*Question
 	if err := DB().Preload("Contest").Order("created_at").Find(&questions).Error; err != nil {
 		return nil, err
@@ -67,9 +67,9 @@ func (q *Question) ReadAll(args map[string]string, r *http.Request) (interface{}
 	return questions, nil
 }
 
-func (q *Question) Update(args map[string]string, r *http.Request) (interface{}, error) {
+func (q *Question) Update(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
-		result, err := q.Read(args, r)
+		result, err := q.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -85,7 +85,7 @@ func (q *Question) Update(args map[string]string, r *http.Request) (interface{},
 
 		return question, nil
 	} else {
-		question, err := q.Read(args, nil)
+		question, err := q.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -97,7 +97,7 @@ func (q *Question) Update(args map[string]string, r *http.Request) (interface{},
 		if err != nil {
 			return nil, err
 		}
-		question, err = q.Read(args, nil)
+		question, err = q.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -105,7 +105,7 @@ func (q *Question) Update(args map[string]string, r *http.Request) (interface{},
 	}
 }
 
-func (q *Question) Delete(args map[string]string, r *http.Request) (interface{}, error) {
+func (q *Question) Delete(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	return nil, nil
 }
 

orm/response.go

@@ -30,7 +30,7 @@ func (model *Response) String() string {
 	return model.Name
 }
 
-func (model *Response) Create(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Response) Create(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
 		response := new(Response)
 		contestID := r.URL.Query().Get("contest_id")
@@ -53,7 +53,7 @@ func (model *Response) Create(args map[string]string, r *http.Request) (interfac
 	}
 }
 
-func (model *Response) Read(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Response) Read(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var response Response
 
 	id := args["id"]
@@ -65,7 +65,7 @@ func (model *Response) Read(args map[string]string, r *http.Request) (interface{
 	return &response, nil
 }
 
-func (model *Response) ReadAll(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Response) ReadAll(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var responses []*Response
 	if err := DB().Preload("Contest", "Participant").Order("created_at").Find(&responses).Error; err != nil {
 		return nil, err
@@ -73,9 +73,9 @@ func (model *Response) ReadAll(args map[string]string, r *http.Request) (interfa
 	return responses, nil
 }
 
-func (model *Response) Update(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Response) Update(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
-		result, err := model.Read(args, r)
+		result, err := model.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -91,7 +91,7 @@ func (model *Response) Update(args map[string]string, r *http.Request) (interfac
 
 		return response, nil
 	} else {
-		response, err := model.Read(args, nil)
+		response, err := model.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -103,7 +103,7 @@ func (model *Response) Update(args map[string]string, r *http.Request) (interfac
 		if err != nil {
 			return nil, err
 		}
-		response, err = model.Read(args, nil)
+		response, err = model.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -111,8 +111,8 @@ func (model *Response) Update(args map[string]string, r *http.Request) (interfac
 	}
 }
 
-func (model *Response) Delete(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *Response) Delete(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
-	response, err := model.Read(args, nil)
+	response, err := model.Read(args, w, r)
 	if err != nil {
 		return nil, err
 	}

orm/user.go

@@ -42,7 +42,7 @@ func (model *User) BeforeSave(tx *gorm.DB) error {
 	return nil
 }
 
-func (model *User) Create(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *User) Create(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
 		user := new(User)
 		// if err := DB().Find(&user.AllContests).Error; err != nil {
@@ -63,7 +63,7 @@ func (model *User) Create(args map[string]string, r *http.Request) (interface{},
 	}
 }
 
-func (model *User) Read(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *User) Read(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var user User
 
 	id := args["id"]
@@ -75,7 +75,7 @@ func (model *User) Read(args map[string]string, r *http.Request) (interface{}, e
 	return &user, nil
 }
 
-func (model *User) ReadAll(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *User) ReadAll(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	var users []*User
 	if err := DB(). /*.Preload("Something")*/ Order("created_at").Find(&users).Error; err != nil {
 		return nil, err
@@ -83,9 +83,9 @@ func (model *User) ReadAll(args map[string]string, r *http.Request) (interface{}
 	return users, nil
 }
 
-func (model *User) Update(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *User) Update(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
 	if r.Method == "GET" {
-		result, err := model.Read(args, r)
+		result, err := model.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -101,7 +101,7 @@ func (model *User) Update(args map[string]string, r *http.Request) (interface{},
 
 		return user, nil
 	} else {
-		user, err := model.Read(args, nil)
+		user, err := model.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -113,7 +113,7 @@ func (model *User) Update(args map[string]string, r *http.Request) (interface{},
 		if err != nil {
 			return nil, err
 		}
-		user, err = model.Read(args, nil)
+		user, err = model.Read(args, w, r)
 		if err != nil {
 			return nil, err
 		}
@@ -121,8 +121,8 @@ func (model *User) Update(args map[string]string, r *http.Request) (interface{},
 	}
 }
 
-func (model *User) Delete(args map[string]string, r *http.Request) (interface{}, error) {
+func (model *User) Delete(args map[string]string, w http.ResponseWriter, r *http.Request) (interface{}, error) {
-	user, err := model.Read(args, nil)
+	user, err := model.Read(args, w, r)
 	if err != nil {
 		return nil, err
 	}

renderer/renderer.go

@@ -8,6 +8,8 @@ import (
 	"io"
 	"log"
 
+	"git.andreafazzi.eu/andrea/oef/config"
+	"github.com/gorilla/sessions"
 	"mime"
 	"net/http"
 	"net/url"
@@ -36,7 +38,7 @@ type htmlTemplateData struct {
 	Data          interface{}
 	Options       url.Values
 	Claims        jwt.MapClaims
-	Error   error
+	FlashMessages []interface{}
 }
 
 type JsonResponse struct {
@@ -45,6 +47,7 @@ type JsonResponse struct {
 }
 
 var (
+	store        = sessions.NewCookieStore([]byte(config.Config.Keys.CookieStoreKey))
 	currRenderer Renderer
 	Render       map[string]func(http.ResponseWriter, *http.Request, interface{}, ...url.Values)
 
@@ -241,12 +244,12 @@ func (rend *HTMLRenderer) writeError(w http.ResponseWriter, r *http.Request, dat
 
 func (rend *HTMLRenderer) Render(w http.ResponseWriter, r *http.Request, data interface{}, options ...url.Values) {
 	if data != nil && isErrorType(data) {
-		rend.writeError(w, r, &htmlTemplateData{data.(error), nil, nil, data.(error)})
+		rend.writeError(w, r, &htmlTemplateData{data.(error), nil, nil, nil})
 	} else {
 		t, ok := rend.templates[options[0]["tpl_content"][0]]
 		if !ok {
 			err := fmt.Errorf("Template %s not found", options[0]["tpl_content"][0])
-			rend.writeError(w, r, &htmlTemplateData{err, nil, nil, err})
+			rend.writeError(w, r, &htmlTemplateData{err, nil, nil, nil})
 		}
 
 		var claims jwt.MapClaims
@@ -256,9 +259,20 @@ func (rend *HTMLRenderer) Render(w http.ResponseWriter, r *http.Request, data in
 		}
 
 		w.Header().Set("Content-Type", "text/html; charset=utf-8")
-		err := t.ExecuteTemplate(w, options[0]["tpl_layout"][0], &htmlTemplateData{data, options[0], claims, nil})
+
+		session, err := store.Get(r, "flash-session")
 		if err != nil {
-			rend.writeError(w, r, &htmlTemplateData{err, nil, nil, err})
+			rend.writeError(w, r, &htmlTemplateData{err, nil, nil, nil})
+		}
+		fm := session.Flashes()
+		err = session.Save(r, w)
+		if err != nil {
+			rend.writeError(w, r, &htmlTemplateData{err, nil, nil, nil})
+		}
+
+		err = t.ExecuteTemplate(w, options[0]["tpl_layout"][0], &htmlTemplateData{data, options[0], claims, fm})
+		if err != nil {
+			rend.writeError(w, r, &htmlTemplateData{err, nil, nil, nil})
 		}
 	}
 }

templates/layout/base.html.tpl

@@ -36,6 +36,17 @@
       </div><!--/.nav-collapse -->
     </nav>
 
+    {{if .FlashMessages}}
+    {{range $message := .FlashMessages}}
+    <div class="alert alert-danger alert-dismissible fade show" role="alert">
+      <strong>Attenzione!</strong> {{$message}}
+      <button type="button" class="close" data-dismiss="alert" aria-label="Close">
+	<span aria-hidden="true">&times;</span>
+      </button>
+    </div>
+    {{end}}
+    {{end}}
+    
     <div class="base-template">
       {{ template "content" . }}
     </div>