Better 404 handling.

Added a 404.html template.
gracedb/view raises Http404 when event is not found.
Event.getByGraceId should now never return None.

gracedb/models.py

@@ -86,7 +86,6 @@ class Event(models.Model):
 
     @classmethod
     def getByGraceid(cls, id):
-        if not id: return None
         if id[0] == "G":
             return cls.objects.get(id=int(id[1:]))
         return cls.objects.get(uid=id)

gracedb/views.py

 
-from django.http import HttpResponse, HttpResponseRedirect, HttpResponseNotFound
+from django.http import HttpResponse
+from django.http import HttpResponseRedirect, HttpResponseNotFound, Http404
 from django.template import RequestContext
 from django.core.urlresolvers import reverse, get_script_prefix
 from django.shortcuts import render_to_response
@@ -202,9 +203,10 @@ def ping(request):
 
 def view(request, graceid):
     context = {}
-    a = Event.getByGraceid(graceid)
-    if not a:
-        return HttpResponseNotFound()
+    try:
+        a = Event.getByGraceid(graceid)
+    except Event.DoesNotExist:
+        raise Http404
     context['object'] = a
     return render_to_response(
         'gracedb/event_detail.html',

templates/404.html

+{% extends "base.html" %}
+
+{% block title %}404 – Not Found{{ object.graceid }}{% endblock %}
+{% block heading %}Not Found {{ object.graceid }}{% endblock %}
+
+{% block content %}
+    <p>The item you requested was not found.</p>
+{% endblock %}