Configure Django messages framework

Use cookie storage and match Bootstrap classes.

accesspoc/accesspoc/settings.py

@@ -9,6 +9,7 @@
 For the full list of settings and their values, see
 https://docs.djangoproject.com/en/1.11/ref/settings/
 """
+from django.contrib.messages import constants as messages
 from django.utils.translation import gettext_lazy as _
 
 from envparse import env
@@ -141,6 +142,16 @@
 
 USE_TZ = True
 
+# Messages
+
+# Force cookie storage to reduce the possibility of looking the database
+# when using SessionStorage, which saves the data in the database by default.
+MESSAGE_STORAGE = 'django.contrib.messages.storage.cookie.CookieStorage'
+# Fix mismatch with Bootstrap alert classes
+MESSAGE_TAGS = {
+    messages.DEBUG: 'secondary',
+    messages.ERROR: 'danger',
+}
 
 # Static files (CSS, JavaScript, Images)
 # https://docs.djangoproject.com/en/1.11/howto/static-files/

accesspoc/templates/base.html

@@ -73,6 +73,16 @@
       </div>
     </nav>
     <div class="main m-4">
+      {% if messages %}
+        {% for message in messages %}
+        <div class="alert alert-{{ message.level_tag }} alert-dismissible fade show" role="alert">
+          {{ message|safe }}
+          <button type="button" class="close" data-dismiss="alert" aria-label="Close">
+            <span aria-hidden="true">&times;</span>
+          </button>
+        </div>
+        {% endfor %}
+      {% endif %}
       {% block content %}
       {% endblock %}
     </div>