fixes bugs in controller

ckanext/odsh/collection/controller.py

@@ -16,7 +16,7 @@ class LatestRecourcesController(PackageController):
     def latest_resource(self, id, type):
         latest_resources = get_latest_resources_for_format(id, format)
         if latest_resources is None:
-            abort(404)
+            toolkit.abort(404)
         url_type = latest_resources.get('url_type')
         if url_type is None:
             resource_url = latest_resources.get('url')
@@ -35,4 +35,4 @@ class LatestRecourcesController(PackageController):
                                     filename=pre_resource_url,
                                     qualified = True)
             toolkit.redirect_to(url_resource)
-        abort(404)
\ No newline at end of file
+        toolkit.abort(404)
\ No newline at end of file

ckanext/odsh/collection/helpers.py

@@ -136,6 +136,8 @@ def get_latest_resources_for_format(collection_name, resource_format):
         return None
     latest_dataset = members[-1]
     resources = latest_dataset.get('resources')
-    resources_with_asked_type = [r for r in resources if r.get('format') == resource_format]
+    if not resources:
+        return None
+    resources_with_asked_type = [r for r in resources if r.get('format').upper() == resource_format.upper()]
     resources_sorted = sorted(resources_with_asked_type, key=itemgetter('id','created'), reverse=True)
     return resources_sorted[-1]