shortening links

rowers/templates/list_workouts.html

@@ -280,7 +280,7 @@
     <div class="site-announcement-box">
       <div class="site-announcement">
         <em>{{ a.created }}:</em>
-        {{ a.announcement|urlize }}
+        {{ a.announcement|urlshorten:20 }}
       </div>
     </div>
   </li>

rowers/templatetags/rowerfilters.py

@@ -31,8 +31,20 @@ from rowers.opaque import encoder
 
 import arrow
 
+from django.utils.safestring import mark_safe
+from django.utils.html import urlize as urlize_impl
+from django.template.defaultfilters import stringfilter
+
 from six import string_types
 
+@register.filter(is_safe=True, needs_autoescape=True)
+@stringfilter
+def urlshorten(value, limit,autoescape=None):
+    return mark_safe(
+        urlize_impl(
+            value, trim_url_limit=int(limit),
+            nofollow=True, autoescape=autoescape).replace('<a', '<a target="_blank"'))
+
 @register.filter
 def nogoals(user):
     targets = TrainingTarget.objects.filter(rowers=user.rower,