extract latest timestamp from feed entries

geojson_client/__init__.py

@@ -28,6 +28,7 @@ def __init__(self, home_coordinates, url, filter_radius=None):
         self._filter_radius = filter_radius
         self._url = url
         self._request = requests.Request(method="GET", url=url).prepare()
+        self._last_timestamp = None
 
     def __repr__(self):
         """Return string representation of this feed."""
@@ -50,7 +51,9 @@ def update(self):
                 for feature in data.features:
                     entries.append(self._new_entry(self._home_coordinates,
                                                    feature, global_data))
-                return UPDATE_OK, self._filter_entries(entries)
+                filtered_entries = self._filter_entries(entries)
+                self._last_timestamp = self._extract_last_timestamp(filtered_entries)
+                return UPDATE_OK, filtered_entries
             else:
                 # Should not happen.
                 return UPDATE_OK, None
@@ -103,6 +106,10 @@ def _extract_from_feed(self, feed):
         """Extract global metadata from feed."""
         return None
 
+    def _extract_last_timestamp(self, feed_entries):
+        """Determine latest (newest) entry from the filtered feed."""
+        return None
+
 
 class FeedEntry:
     """Feed entry base class."""

geojson_client/feed_manager.py

@@ -14,14 +14,15 @@ class FeedManagerBase:
     """Generic Feed manager."""
 
     def __init__(self, feed, generate_callback, update_callback,
-                 remove_callback):
+                 remove_callback, persistent_timestamp=False):
         """Initialise feed manager."""
         self._feed = feed
         self.feed_entries = {}
         self._managed_external_ids = set()
         self._generate_callback = generate_callback
         self._update_callback = update_callback
         self._remove_callback = remove_callback
+        self._persistent_timestamp = persistent_timestamp
 
     def __repr__(self):
         """Return string representation of this feed."""

geojson_client/nsw_rural_fire_service_feed.py

@@ -80,6 +80,14 @@ def _filter_entries(self, entries):
                                entries))
         return entries
 
+    def _extract_last_timestamp(self, feed_entries):
+        """Determine latest (newest) entry from the filtered feed."""
+        if feed_entries:
+            dates = sorted([entry.publication_date for entry in feed_entries],
+                           reverse=True)
+            return dates[0]
+        return None
+
 
 class NswRuralFireServiceFeedEntry(FeedEntry):
     """NSW Rural Fire Service feed entry."""

geojson_client/usgs_earthquake_hazards_program_feed.py

@@ -100,6 +100,14 @@ def _filter_entries(self, entries):
                                _filter_minimum_magnitude, entries))
         return entries
 
+    def _extract_last_timestamp(self, feed_entries):
+        """Determine latest (newest) entry from the filtered feed."""
+        if feed_entries:
+            dates = sorted([entry.updated for entry in feed_entries],
+                           reverse=True)
+            return dates[0]
+        return None
+
     def _extract_from_feed(self, feed):
         """Extract global metadata from feed."""
         global_data = {}