add Event.view_url property

locklost/event.py

@@ -84,6 +84,11 @@ class LocklossEvent(object):
         """generate event URL path"""
         return os.path.join(self.url, *args)
 
+    @property
+    def view_url(self):
+        """event URL"""
+        return '{}?event={}'.format(config.WEB_ROOT, self.id)
+
     @property
     def transition_index(self):
         """tuple of indices of Guardian state transition"""
@@ -372,7 +377,7 @@ class LocklossEvent(object):
             'gps': self.gps,
             'utc': self.utc,
             'url': self.url,
-            'view_url': os.path.join(config.WEB_ROOT, 'index.cgi?event={}'.format(self.id)),
+            'view_url': self.view_url,
             'transition_index': self.transition_index,
             'analyzed': self.analyzed,
             'analysis_version': self.analysis_version,

locklost/plots.py

@@ -36,17 +36,11 @@ def event_dn(e):
     return gps2dn(e.gps)
 
 
-def event_url(e):
-    """return event URL"""
-    url = '{}?event={}'.format(config.WEB_ROOT, e.id)
-    return url
-
-
 def escatter(events, **kwargs):
     """scatter plot of events"""
     x = [event_dn(e) for e in events]
     y = [e.transition_index[0] for e in events]
-    urls = [event_url(e) for e in events]
+    urls = [e.view_url for e in events]
     s = plt.scatter(
         x, y,
         linewidth=0,