custom management command that sets an announcement banner on front page

general/management/commands/announcement_cache.py

@@ -0,0 +1,45 @@
+"""Custom management command to set/clear announcement_cache for front page announcements banner.
+
+The announcement banner is a simple HTML snippet cached in the Django cache. It is formed by a title and a text
+that are passed as arguments to the command. The command can be used to set the cache, clear it, or show the current
+value of the cache.
+
+Example usage:
+    python manage.py announcement_cache set "New feature!" "Now you can do this and that. <a href='/forum'>Learn more</a>"
+    python manage.py announcement_cache clear
+    python manage.py announcement_cache show
+
+"""
+from django.core.cache import cache
+from django.core.management.base import BaseCommand
+from django.template.loader import render_to_string
+
+
+class Command(BaseCommand):
+    help = 'Set/clear "announcement_cache" for front page announcements banner'
+
+    def add_arguments(self, parser):
+        parser.add_argument("action", type=str, help="Indicates whether to set or clear the cache")
+        parser.add_argument("title", type=str, nargs="?", help="Title of the announcement")
+        parser.add_argument("text", type=str, nargs="?", help="Text of the announcement")
+
+    def handle(self, *args, **kwargs):
+        action = kwargs["action"]
+        title = kwargs["title"]
+        text = kwargs["text"]
+
+        announcement_cache_key = "announcement_cache"
+        if action == "set":
+            one_day = 60 * 60 * 24
+            value = render_to_string("molecules/announcement_banner.html", {"title": title, "text": text})
+            cache.set(announcement_cache_key, value, one_day)
+            self.stdout.write(self.style.SUCCESS("Successfully set announcement_cache"))
+        elif action == "clear":
+            cache.delete(announcement_cache_key)
+            self.stdout.write(self.style.SUCCESS("Successfully cleared announcement_cache"))
+        elif action == "show":
+            current_value = cache.get(announcement_cache_key, "<<Cache is empty>>")
+            self.stdout.write(self.style.SUCCESS("Current value of announcement_cache:"))
+            self.stdout.write(current_value)
+        else:
+            self.stdout.write(self.style.ERROR('Invalid action. Use "set" or "clear".'))

templates/front.html

@@ -41,6 +41,10 @@ <h3 class="v-spacing-4">Latest additions</h3>
                     </section>
                     {% endcache %}
                 {% endif %}
+
+                {%  if announcement_cache %}
+                    {{ announcement_cache }}
+                {% endif %}
 
                 {% if rss_cache %}
                     {{ rss_cache }}

templates/molecules/announcement_banner.html

@@ -0,0 +1,8 @@
+<div class="v-spacing-6">
+    <section class="border-grey-light">
+        <h3 class="text-center v-spacing-2 ellipsis">{{ title }}</h3>
+        <div class="center">
+            {{ text | safe }}
+        </div>
+    </section>
+</div>