Support multiple on parameter set callbacks

Signed-off-by: Abhinav Singh <singhabhinav9051571833@gmail.com>

rclpy/rclpy/duration.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import builtin_interfaces
+import builtin_interfaces.msg
 from rclpy.impl.implementation_singleton import rclpy_implementation as _rclpy
 
 

rclpy/rclpy/node.py

@@ -146,8 +146,8 @@ def __init__(
         self.__guards: List[GuardCondition] = []
         self.__waitables: List[Waitable] = []
         self._default_callback_group = MutuallyExclusiveCallbackGroup()
+        self._parameters_callback: List[Callable[[List[Parameter]], SetParametersResult]] = []
         self._rate_group = ReentrantCallbackGroup()
-        self._parameters_callback = None
         self._allow_undeclared_parameters = allow_undeclared_parameters
         self._parameter_overrides = {}
         self._descriptors = {}
@@ -715,9 +715,11 @@ def _set_parameters_atomically(
         if not result.successful:
             return result
         elif self._parameters_callback:
-            result = self._parameters_callback(parameter_list)
-        else:
-            result = SetParametersResult(successful=True)
+            for callback in self._parameters_callback:
+                result = callback(parameter_list)
+                if(not result.successful):
+                    return result
+        result = SetParametersResult(successful=True)
 
         if result.successful:
             parameter_event = ParameterEvent()
@@ -761,6 +763,25 @@ def _set_parameters_atomically(
 
         return result
 
+    def add_on_set_paramters_callback(
+        self,
+        callback: Callable[[List[Parameter]], SetParametersResult]
+    ) -> None:
+        """Add the callback to list."""
+        prevCallBack = self._parameters_callback
+        prevCallBack.insert(0, callback)
+        self._parameters_callback = prevCallBack
+
+    def remove_on_set_parameters_callback(
+        self,
+        callback: Callable[[List[Parameter]], SetParametersResult]
+    ) -> None:
+        """Remove callback from list."""
+        if callback in self._parameters_callback:
+            self._parameters_callback.remove(callback)
+        else:
+            print('Callback does not exist')
+
     def _apply_descriptors(
         self,
         parameter_list: List[Parameter],
@@ -1019,7 +1040,7 @@ def set_parameters_callback(
         """
         Register a set parameters callback.
 
-        Calling this function with override any previously registered callback.
+        Calling this function will override any previously registered callback.
 
         :param callback: The function that is called whenever parameters are set for the node.
         """

rclpy/rclpy/time.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import builtin_interfaces
+import builtin_interfaces.msg
 from rclpy.clock import ClockType
 from rclpy.duration import Duration
 from rclpy.impl.implementation_singleton import rclpy_implementation as _rclpy