feat: Add interface and service for retrieving action type (#1046)

* Added ActionType service and related functionality

- Introduced ActionType service to retrieve the type of a specified ROS action.
- Updated proxy to include logic for determining action types based on existing action servers.
- Modified rosapi_node to create the new ActionType service endpoint.
- Added ActionType message definition in rosapi_msgs.

* Fix pre-commit hook issues: end-of-file and trailing-whitespace

* reverted back vscode settings.json

* Refactor get_action_type to use get_action_names_and_types for improved action type retrieval. Removed outdated logic for action server filtering and topic name extraction.

* Update get_action_type function to set include_hidden parameter default to False for consistency with other functions.

* Added ros2action as a runtime dependency in package.xml

Author: chaitanya-mandala

rosapi/package.xml

@@ -25,6 +25,7 @@
   <exec_depend>rosbridge_library</exec_depend>
   <exec_depend>ros2node</exec_depend>
   <exec_depend>ros2service</exec_depend>
+  <exec_depend>ros2action</exec_depend>
   <exec_depend>ros2topic</exec_depend>
 
   <test_depend>ament_cmake_mypy</test_depend>

rosapi/scripts/rosapi_node

@@ -47,6 +47,7 @@ from rosapi_msgs.srv import (
     ActionFeedbackDetails,
     ActionGoalDetails,
     ActionResultDetails,
+    ActionType,
     DeleteParam,
     GetActionServers,
     GetParam,
@@ -112,6 +113,7 @@ class Rosapi(Node):
         self.create_service(Nodes, "~/nodes", self.get_nodes)
         self.create_service(NodeDetails, "~/node_details", self.get_node_details)
         self.create_service(GetActionServers, "~/action_servers", self.get_action_servers)
+        self.create_service(ActionType, "~/action_type", self.get_action_type)
         self.create_service(TopicType, "~/topic_type", self.get_topic_type)
         self.create_service(ServiceType, "~/service_type", self.get_service_type)
         self.create_service(Publishers, "~/publishers", self.get_publishers)
@@ -335,6 +337,12 @@ class Rosapi(Node):
         ]
         return response
 
+    def get_action_type(self, request, response):
+        """Called by the rosapi/ActionType service. Given the name of an action, returns its type.
+        If the action does not exist, an empty string is returned."""
+        response.type = proxy.get_action_type(request.action)
+        return response
+
     async def set_param(self, request, response):
         try:
             node_name, param_name = self._get_node_and_param_name(request.name)

rosapi/src/rosapi/proxy.py

@@ -31,6 +31,7 @@
 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
+from ros2action.api import get_action_names_and_types
 from ros2interface.api import type_completer
 from ros2node.api import (
     get_node_names,
@@ -264,3 +265,16 @@ def get_service_node(queried_type, services_glob, include_hidden=False):
         return node_name[0]
     else:
         return ""
+
+
+def get_action_type(action_name, include_hidden=False):
+    """Returns the type of the specified ROS action.
+    If the action does not exist, an empty string is returned."""
+
+    names_and_types = get_action_names_and_types(node=_node, include_hidden_actions=include_hidden)
+
+    for name, types in names_and_types:
+        if name == action_name and types:
+            return types[0]
+
+    return ""

rosapi_msgs/CMakeLists.txt

@@ -26,6 +26,7 @@ rosidl_generate_interfaces(${PROJECT_NAME}
   srv/ActionGoalDetails.srv
   srv/ActionResultDetails.srv
   srv/ActionFeedbackDetails.srv
+  srv/ActionType.srv
   srv/Services.srv
   srv/ServicesForType.srv
   srv/ServiceType.srv

rosapi_msgs/srv/ActionType.srv

@@ -0,0 +1,3 @@
+string action
+---
+string type