Add error messages in login page

2 files changed, 14 insertions, 4 deletions

diff --git a/main.go b/main.go
index 34667cf..86fd969 100644
--- a/main.go
+++ b/main.go
@@ -75,15 +75,23 @@ func (app *App) loginHandler(w http.ResponseWriter, r *http.Request) {
 			http.SetCookie(w, &c)
 			http.Redirect(w, r, next, http.StatusSeeOther)
 		} else {
+			var flash string
+			if !ok {
+				flash = "Utilisateur non enregistré"
+			} else if subtle.ConstantTimeCompare(u.Password, hash) != 1 {
+				flash = "Mot de passe incorrect"
+			}
 			app.Template.ExecuteTemplate(w, "login.tmpl", struct {
-				Next string
-			}{next})
+				Next  string
+				Flash string
+			}{next, flash})
 		}
 	} else if r.Method == http.MethodGet {
 		next := r.FormValue("next")
 		app.Template.ExecuteTemplate(w, "login.tmpl", struct {
-			Next string
-		}{next})
+			Next  string
+			Flash string
+		}{next, ""})
 	}
 }
 
diff --git a/templates/login.tmpl b/templates/login.tmpl
index 6f76a4a..a78fdc1 100644
--- a/templates/login.tmpl
+++ b/templates/login.tmpl
@@ -9,6 +9,7 @@ body{margin: 0 auto; width: 400px; padding-top: 10em; font-family: "Source Sans
 form > hr{border: none; border-top: 1px solid #e6e6e6; margin: 1.3em 0;}
 form > h4{font-weight: 300; font-size: 19px; margin-bottom: 0} label {font-weight: bold; text-align: right;}
 form > div {display: grid; grid-template-columns: 2fr 5fr; grid-gap: 1em 1em; align-items: center;}
+form .alert { background-color: #ff0039; grid-column: 1 / 3; color: white; padding: 0.8em 1em}
 input, button {font-size: inherit; font-family: inherit; line-height: inherit; padding: 0.8em 1em; border-radius: 0}
 input {border: 1px solid #cccccc; transition: border-color ease-in-out .15s,box-shadow ease-in-out .15s}
 input:focus {border-color: #66afe9; outline: 0; box-shadow: inset 0 1px 1px rgba(0,0,0,0.075),0 0 8px rgba(102,175,233,0.6)}
@@ -28,6 +29,7 @@ button:hover {background-color: #1967be; border-color: #1862b5}
 	<label for="password">Mot de passe :</label>
 	<input type="password" id="password" name="password" placeholder="Mot de passe"/>
 
+	{{ if .Flash }} <div class="alert">{{.Flash}}</div> {{end}}
 	<button type="submit" name="login">Se Connecter</button>
 	<input type="hidden" name="next" value="{{.Next}}"/>
   </div>