handlers: update error handling

* have a common error page tmpl

handlers/handlers.go

@@ -286,7 +286,17 @@ func Signup() echo.HandlerFunc {
 		)
 		if err != nil {
 			log.Warnf("error: %q", err)
-			http.Error(c.Response().Writer, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+
+			err = renderErrorPage(
+				c.Response().Writer,
+				http.StatusInternalServerError,
+				http.StatusText(http.StatusInternalServerError),
+				err.Error(),
+			)
+
+			if err != nil {
+				return err
+			}
 		}
 
 		return nil
@@ -353,15 +363,25 @@ func Home() echo.HandlerFunc {
 		if err != nil {
 			if err == http.ErrNoCookie {
 				log.Infof("error no cookie: %q", err)
-				http.Error(c.Response().Writer, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
+
+				err = renderErrorPage(
+					c.Response().Writer,
+					http.StatusNotFound, http.StatusText(http.StatusNotFound),
+					err.Error(),
+				)
+
+				if err != nil {
+					c.Logger().Errorf("error: %q", err)
+
+					return err
+				}
 
 				return nil
 			}
 
-			log.Infof("error: %q", err)
-			http.Error(c.Response().Writer, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
+			c.Logger().Errorf("error: %q", err)
 
-			return nil
+			return echo.NewHTTPError(http.StatusBadRequest, http.StatusText(http.StatusBadRequest))
 		}
 
 		if session != nil {
@@ -370,7 +390,22 @@ func Home() echo.HandlerFunc {
 			if err := session.Valid(); err != nil {
 				log.Warn("invalid or expired session?")
 
-				return echo.NewHTTPError(http.StatusUnauthorized, http.StatusText(http.StatusUnauthorized))
+				c.Logger().Errorf("error: %q", err)
+
+				err = renderErrorPage(
+					c.Response().Writer,
+					http.StatusNotFound, http.StatusText(http.StatusNotFound),
+					err.Error(),
+				)
+
+				if err != nil {
+					c.Logger().Errorf("error: %q", err)
+
+					return echo.NewHTTPError(
+						http.StatusInternalServerError,
+						http.StatusText(http.StatusInternalServerError),
+					)
+				}
 			}
 
 			username = session.Value
@@ -395,7 +430,22 @@ func Home() echo.HandlerFunc {
 		if err != nil {
 			log.Warnf("error: %q", err)
 
-			return echo.NewHTTPError(http.StatusInternalServerError, http.StatusText(http.StatusInternalServerError))
+			c.Logger().Errorf("error: %q", err)
+
+			err = renderErrorPage(
+				c.Response().Writer,
+				http.StatusInternalServerError, http.StatusText(http.StatusInternalServerError),
+				err.Error(),
+			)
+
+			if err != nil {
+				c.Logger().Errorf("error: %q", err)
+
+				return echo.NewHTTPError(
+					http.StatusInternalServerError,
+					http.StatusText(http.StatusInternalServerError),
+				)
+			}
 		}
 
 		return nil
@@ -413,9 +463,9 @@ func Logout() echo.HandlerFunc {
 					return c.Redirect(302, "/signin")
 				}
 
-				log.Warnf("error: %q", err)
+				c.Logger().Errorf("error: %q", err)
 
-				return nil
+				return err
 			}
 
 			var username string
@@ -451,7 +501,20 @@ func Logout() echo.HandlerFunc {
 		if err != nil {
 			log.Warnf("error: %q", err)
 
-			return echo.NewHTTPError(http.StatusInternalServerError, http.StatusText(http.StatusInternalServerError))
+			c.Logger().Errorf("error: %q", err)
+
+			err = renderErrorPage(
+				c.Response().Writer,
+				http.StatusInternalServerError,
+				http.StatusText(http.StatusInternalServerError),
+				err.Error(),
+			)
+
+			if err != nil {
+				c.Logger().Errorf("error: %q", err)
+
+				return err
+			}
 		}
 
 		return nil

handlers/helper.go

@@ -0,0 +1,30 @@
+package handlers
+
+import (
+	"fmt"
+	"io"
+	"strconv"
+)
+
+func renderErrorPage(wr io.Writer, status int, statusText, error string) error {
+	tpl := getTmpl("errorPage.tmpl")
+	strStatus := strconv.Itoa(status)
+
+	err := tpl.Execute(wr,
+		page{
+			AppName:    conf.AppName,
+			AppVer:     appver,
+			Title:      fmt.Sprintf("Error %s - %s", strStatus, statusText),
+			DevelMode:  conf.DevelMode,
+			Current:    strStatus,
+			Error:      error,
+			Status:     strStatus,
+			StatusText: statusText,
+		},
+	)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

handlers/page.go

@@ -8,4 +8,7 @@ type page struct {
 	CSRF       string
 	DevelMode  bool
 	Current    string
+	Error      string
+	Status     string
+	StatusText string
 }

templates/500.tmpl

@@ -1,5 +0,0 @@
-{{ template "head.tmpl" . }}
-<body>
-	<div class="cover"><h1>Webservice currently unavailable <small>500</small></h1><p class="lead">An unexpected condition was encountered.<br />Our service team has been dispatched to bring it back online.</p></div>
-    
-{{ template "footer.tmpl" . }}

templates/errorPage.tmpl

@@ -0,0 +1,21 @@
+{{ template "head.tmpl" . }}
+<body class="h-screen bg-white dark:bg-gray-900">
+{{ template "navbar.tmpl" . }}
+<main class="grow">
+	<div class="container mx-auto md:items-center text-center">
+		<div class="place-items-center text-center">
+			<h1 class="p-2 mt-10 text-4xl font-bold text-purple-700 dark:text-purple-400">
+				{{ .Status }} - {{ .StatusText }}
+			</h1>
+			{{ if .DevelMode }}
+				<p class="p-2 mt-4 text-xl font-medium text-red-500">
+					Error: {{ .Error }}<br />
+				</p>
+			{{ end }}
+			<div class="w-1/2 md:w-full px-auto py-3 mx-auto text-sm font-medium tracking-wide text-blue-300 dark:text-blue-500 transition-colors duration-300 hover:underline">
+				<a href="/">Get back home</a>
+			</div>
+		</div>
+	</div>
+	</main>
+{{ template "footer.tmpl" . }}