implement application properties filter (#78)

* This PR implements application properties filtering for AMQP streams, enabling consumers to filter messages based on their application-level properties. This completes the feature request tracked in issue #42.

Adds support for filtering messages by application properties in stream consumers
Updates the example to demonstrate both message properties and application properties filtering
Extends the StreamConsumerOptions class with application properties filter handling


---------

Signed-off-by: Gabriele Santomaggio <[email protected]>
Co-authored-by: Copilot <[email protected]>

Author: Gsantomaggio

examples/streams_with_filters/example_streams_with_filters.py

@@ -29,11 +29,13 @@ def __init__(self):
 
     def on_amqp_message(self, event: Event):
         # only messages with banana filters and with subject yellow
+        # and application property from = italy get received
         self._count = self._count + 1
         logger.info(
-            "Received message: {}, subject {}.[Total Consumed: {}]".format(
+            "Received message: {}, subject {} application properties {} .[Total Consumed: {}]".format(
                 Converter.bytes_to_string(event.message.body),
                 event.message.subject,
+                event.message.application_properties,
                 self._count,
             )
         )
@@ -88,13 +90,15 @@ def main() -> None:
         addr_queue,
         message_handler=MyMessageHandler(),
         # the consumer will only receive messages with filter value banana and subject yellow
+        # and application property from = italy
         stream_consumer_options=StreamConsumerOptions(
             offset_specification=OffsetSpecification.first,
             filter_options=StreamFilterOptions(
                 values=["banana"],
                 message_properties=MessageProperties(
                     subject="yellow",
                 ),
+                application_properties={"from": "italy"},
             ),
         ),
     )
@@ -108,11 +112,13 @@ def main() -> None:
     # publish with a filter of apple
     for i in range(MESSAGES_TO_PUBLISH):
         color = "green" if i % 2 == 0 else "yellow"
+        from_value = "italy" if i % 3 == 0 else "spain"
         publisher.publish(
             Message(
                 Converter.string_to_bytes(body="apple: " + str(i)),
                 annotations={"x-stream-filter-value": "apple"},
                 subject=color,
+                application_properties={"from": from_value},
             )
         )
 
@@ -121,11 +127,13 @@ def main() -> None:
     # publish with a filter of banana
     for i in range(MESSAGES_TO_PUBLISH):
         color = "green" if i % 2 == 0 else "yellow"
+        from_value = "italy" if i % 3 == 0 else "spain"
         publisher.publish(
             Message(
                 body=Converter.string_to_bytes("banana: " + str(i)),
                 annotations={"x-stream-filter-value": "banana"},
                 subject=color,
+                application_properties={"from": from_value},
             )
         )
 

rabbitmq_amqp_python_client/entities.py

@@ -11,6 +11,7 @@
 STREAM_OFFSET_SPEC = "rabbitmq:stream-offset-spec"
 STREAM_FILTER_MATCH_UNFILTERED = "rabbitmq:stream-match-unfiltered"
 AMQP_PROPERTIES_FILTER = "amqp:properties-filter"
+AMQP_APPLICATION_PROPERTIES_FILTER = "amqp:application-properties-filter"
 
 
 @dataclass
@@ -252,6 +253,11 @@ def __init__(
 
         if filter_options is not None and filter_options.message_properties is not None:
             self._filter_message_properties(filter_options.message_properties)
+        if (
+            filter_options is not None
+            and filter_options.application_properties is not None
+        ):
+            self._filter_application_properties(filter_options.application_properties)
 
     def _offset(self, offset_specification: Union[OffsetSpecification, int]) -> None:
         """
@@ -316,6 +322,18 @@ def _filter_message_properties(
                     symbol(AMQP_PROPERTIES_FILTER), filter_prop
                 )
 
+    def _filter_application_properties(
+        self, application_properties: Optional[dict[str, Any]]
+    ) -> None:
+        app_prop = {}
+        if application_properties is not None:
+            app_prop = application_properties.copy()
+
+            if len(app_prop) > 0:
+                self._filter_set[symbol(AMQP_APPLICATION_PROPERTIES_FILTER)] = (
+                    Described(symbol(AMQP_APPLICATION_PROPERTIES_FILTER), app_prop)
+                )
+
     def filter_set(self) -> Dict[symbol, Described]:
         """
         Get the current filter set configuration.