Make change_datetime accept a format arg

changedetectionio/notification_service.py

@@ -54,14 +54,45 @@ def _check_cascading_vars(datastore, var_name, watch):
     return None
 
 
+class FormattableTimestamp:
+    """
+    A datetime wrapper that renders with a default strftime format when used as a string,
+    but can also be called with a custom format argument in Jinja2 templates:
+
+        {{ change_datetime }}                        → '2024-01-15 10:30:00 UTC'
+        {{ change_datetime(format='%Y') }}           → '2024'
+        {{ change_datetime(format='%Y-%m-%d') }}     → '2024-01-15'
+    """
+    _DEFAULT_FORMAT = '%Y-%m-%d %H:%M:%S %Z'
+
+    def __init__(self, timestamp):
+        dt = datetime.datetime.fromtimestamp(int(timestamp), tz=pytz.UTC)
+        local_tz = datetime.datetime.now().astimezone().tzinfo
+        self._dt = dt.astimezone(local_tz)
+
+    def __call__(self, format=_DEFAULT_FORMAT):
+        try:
+            return self._dt.strftime(format)
+        except Exception:
+            return self._dt.isoformat()
+
+    def __str__(self):
+        try:
+            return self._dt.strftime(self._DEFAULT_FORMAT)
+        except Exception:
+            return self._dt.isoformat()
+
+    def __repr__(self):
+        return self.__str__()
+
+
 # What is passed around as notification context, also used as the complete list of valid {{ tokens }}
 class NotificationContextData(dict):
     def __init__(self, initial_data=None, **kwargs):
         # ValidateJinja2Template() validates against the keynames of this dict to check for valid tokens in the body (user submission)
         super().__init__({
             'base_url': None,
-            'change_datetime': None,
-            'change_datetime_z': None,
+            'change_datetime': FormattableTimestamp(time.time()),
             'current_snapshot': None,
             'diff': None,
             'diff_added': None,
@@ -108,7 +139,7 @@ class NotificationContextData(dict):
         So we can test the output in the notification body
         """
         for key in self.keys():
-            if key in ['uuid', 'time', 'watch_uuid']:
+            if key in ['uuid', 'time', 'watch_uuid', 'change_datetime']:
                 continue
             rand_str = 'RANDOM-PLACEHOLDER-'+''.join(random.choices(string.ascii_letters + string.digits, k=12))
             self[key] = rand_str
@@ -120,35 +151,6 @@ class NotificationContextData(dict):
 
         super().__setitem__(key, value)
 
-def timestamp_to_localtime_iso8601(timestamp):
-    # Interpret timestamp as UTC
-    dt_utc = datetime.datetime.fromtimestamp(int(timestamp), tz=pytz.UTC)
-
-    # Convert to local timezone
-    local_dt = dt_utc.astimezone()
-
-    # Return ISO 8601 format
-    return local_dt.isoformat()
-
-def timestamp_to_localtime(timestamp):
-    # Format the date using locale-aware formatting with timezone
-    # Pass tz=UTC so fromtimestamp() interprets the epoch correctly as UTC,
-    # rather than converting to local time first and then mislabelling it as UTC.
-    dt = datetime.datetime.fromtimestamp(int(timestamp), tz=pytz.UTC)
-
-    # Get local timezone-aware datetime
-    local_tz = datetime.datetime.now().astimezone().tzinfo
-    local_dt = dt.astimezone(local_tz)
-
-    # Format date with timezone - using strftime for locale awareness
-    try:
-        formatted_date = local_dt.strftime('%Y-%m-%d %H:%M:%S %Z')
-    except:
-        # Fallback if locale issues
-        formatted_date = local_dt.isoformat()
-
-    return formatted_date
-
 def add_rendered_diff_to_notification_vars(notification_scan_text:str, prev_snapshot:str, current_snapshot:str, word_diff:bool):
     """
     Efficiently renders only the diff placeholders that are actually used in the notification text.
@@ -214,8 +216,7 @@ def set_basic_notification_vars(current_snapshot, prev_snapshot, watch, triggere
         'current_snapshot': current_snapshot,
         'prev_snapshot': prev_snapshot,
         'screenshot': watch.get_screenshot() if watch and watch.get('notification_screenshot') else None,
-        'change_datetime': timestamp_to_localtime(timestamp_changed) if timestamp_changed else None,
-        'change_datetime_z': timestamp_to_localtime_iso8601(timestamp_changed) if timestamp_changed else None,
+        'change_datetime': FormattableTimestamp(timestamp_changed) if timestamp_changed else None,
         'triggered_text': triggered_text,
         'uuid': watch.get('uuid') if watch else None,
         'watch_url': watch.get('url') if watch else None,

changedetectionio/templates/_common_fields.html

@@ -45,12 +45,8 @@
                 <td>{{ _('The URL of the preview page generated by changedetection.io.') }}</td>
             </tr>
             <tr>
-                <td><code>{{ '{{change_datime}}' }}</code></td>
-                <td>{{ _('Date/time of the change in \'%Y-%m-%d %H:%M:%S %Z\' format') }}</td>
-            </tr>
-            <tr>
-                <td><code>{{ '{{change_datime_z}}' }}</code></td>
-                <td>{{ _('Date/time of the change in ISO-8601 format') }}</td>
+                <td><code>{{ '{{change_datetime}}' }}</code></td>
+                <td>{{ _('Date/time of the change, accepts format=, change_datetime(format=\'%A\')\', default is \'%Y-%m-%d %H:%M:%S %Z\'') }}</td>
             </tr>
             <tr>
                 <td><code>{{ '{{diff_url}}' }}</code></td>

changedetectionio/tests/test_notification.py

@@ -17,6 +17,7 @@ from changedetectionio.notification import (
 )
 from ..diff import HTML_CHANGED_STYLE
 from ..model import USE_SYSTEM_DEFAULT_NOTIFICATION_FORMAT_FOR_WATCH
+from ..notification_service import FormattableTimestamp
 
 
 # Hard to just add more live server URLs when one test is already running (I think)
@@ -109,7 +110,8 @@ def test_check_notification(client, live_server, measure_memory_usage, datastore
                                                    "Diff Full: {{diff_full}}\n"
                                                    "Diff as Patch: {{diff_patch}}\n"
                                                    "Change datetime: {{change_datetime}}\n"
-                                                   "Change datetime Z: {{change_datetime_z}}\n"
+                                                   "Change datetime format: Weekday {{change_datetime(format='%A')}}\n"
+                                                   "Change datetime format: {{change_datetime(format='%Y-%m-%dT%H:%M:%S%z')}}\n"
                                                    ":-)",
                               "notification_screenshot": True,
                               "notification_format": 'text'}
@@ -178,15 +180,15 @@ def test_check_notification(client, live_server, measure_memory_usage, datastore
     notification_submission_object = json.loads(notification_submission)
     assert notification_submission_object
 
-    # timestamp worked
     import time
-    from changedetectionio.notification_service import timestamp_to_localtime, timestamp_to_localtime_iso8601
     # Could be from a few seconds ago (when the notification was fired vs in this test checking), so check for any
-    times_possible = [timestamp_to_localtime(int(time.time()) - i) for i in range(15)]
+    times_possible = [str(FormattableTimestamp(int(time.time()) - i)) for i in range(15)]
     assert any(t in notification_submission for t in times_possible)
 
-    times_possible = [timestamp_to_localtime_iso8601(int(time.time()) - i) for i in range(15)]
-    assert any(t in notification_submission for t in times_possible)
+    txt = f"Weekday {FormattableTimestamp(int(time.time()))(format='%A')}"
+    assert txt in notification_submission
+
+
 
 
     # We keep PNG screenshots for now