feat: Add domain customtag

src/fellchensammlung/templates/fellchensammlung/details/detail_adoption_notice.html

@@ -48,7 +48,14 @@
                 <td>{{ adoption_notice.searching_since }}</td>
                 <td>{{ adoption_notice.last_checked | date:'d. F Y' }}</td>
                 {% if adoption_notice.further_information %}
-                    <td>{{ adoption_notice.link_to_more_information | safe }}</td>
+                    <td>
+                        <form method="get" action="{% url 'external-site' %}">
+                            <input type="hidden" name="url" value="adoption_notice.further_information">
+                            <button class="btn" type="submit" id="submit">
+                                 {{ adoption_notice.further_information | domain }} <i class="fa-solid fa-arrow-up-right-from-square"></i>
+                            </button>
+                        </form>
+                    </td>
                 {% else %}
                     <td>-</td>
                 {% endif %}

src/fellchensammlung/templatetags/custom_tags.py

@@ -4,6 +4,7 @@ from django import template
 from django.template.defaultfilters import stringfilter
 from django.utils.safestring import mark_safe
 from notfellchen import settings
+from urllib.parse import urlparse
 
 register = template.Library()
 
@@ -56,6 +57,17 @@ def pointdecimal(value):
     except ValueError:
         return value
 
+@register.filter
+@stringfilter
+def domain(url):
+    try:
+        domain = urlparse(url).netloc
+        if domain.startswith("www."):
+            return domain[4:]
+        return domain
+    except ValueError:
+        return url
+
 @register.simple_tag
 def settings_value(name):
     return getattr(settings, name)