Update Custom-ROS2-Interfaces.rst

source/Tutorials/Beginner-Client-Libraries/Custom-ROS2-Interfaces.rst

@@ -661,55 +661,46 @@ Since you'll be changing the original two integer request srv to a three integer
 
     .. code-block:: python
 
-      from tutorial_interfaces.srv import AddThreeInts                            # CHANGE
-      import sys
-      import rclpy
-      from rclpy.node import Node
-
-
-      class MinimalClientAsync(Node):
-
-          def __init__(self):
-              super().__init__('minimal_client_async')
-              self.cli = self.create_client(AddThreeInts, 'add_three_ints')       # CHANGE
-              while not self.cli.wait_for_service(timeout_sec=1.0):
-                  self.get_logger().info('service not available, waiting again...')
-              self.req = AddThreeInts.Request()                                   # CHANGE
-
-          def send_request(self):
-              self.req.a = int(sys.argv[1])
-              self.req.b = int(sys.argv[2])
-              self.req.c = int(sys.argv[3])                                       # CHANGE
-              self.future = self.cli.call_async(self.req)
-
-
-      def main(args=None):
-          rclpy.init(args=args)
-
-          minimal_client = MinimalClientAsync()
-          minimal_client.send_request()
-
-          while rclpy.ok():
-              rclpy.spin_once(minimal_client)
-              if minimal_client.future.done():
-                  try:
-                      response = minimal_client.future.result()
-                  except Exception as e:
-                      minimal_client.get_logger().info(
-                          'Service call failed %r' % (e,))
-                  else:
-                      minimal_client.get_logger().info(
-                          'Result of add_three_ints: for %d + %d + %d = %d' %                                # CHANGE
-                          (minimal_client.req.a, minimal_client.req.b, minimal_client.req.c, response.sum))  # CHANGE
-                  break
-
-          minimal_client.destroy_node()
-          rclpy.shutdown()
-
-
-      if __name__ == '__main__':
-          main()
-
+        import sys
+
+        from tutorial_interfaces.srv import AddThreeInts                                 # CHANGE
+        import rclpy
+        from rclpy.node import Node
+
+
+        class MinimalClientAsync(Node):
+
+            def __init__(self):
+                super().__init__('minimal_client_async')
+                self.cli = self.create_client(AddThreeInts, 'add_three_ints')             # CHANGE
+                while not self.cli.wait_for_service(timeout_sec=1.0):
+                    self.get_logger().info('service not available, waiting again...')
+                self.req = AddThreeInts.Request()
+
+            def send_request(self, a, b, c):                                              # CHANGE
+                self.req.a = a
+                self.req.b = b
+                self.req.c = c                                                            # CHANGE
+                return self.cli.call_async(self.req)
+
+
+        def main():
+            rclpy.init()
+
+            minimal_client = MinimalClientAsync()
+            future = minimal_client.send_request(int(sys.argv[1]), int(sys.argv[2]), int(sys.argv[3]))    # CHANGE
+            rclpy.spin_until_future_complete(minimal_client, future)
+            response = future.result()
+            minimal_client.get_logger().info(
+                'Result of add_three_ints: for %d + %d + %d = %d' %                                       # CHANGE
+                (int(sys.argv[1]), int(sys.argv[2]), int(sys.argv[3]), response.sum))                     # CHANGE
+
+            minimal_client.destroy_node()
+            rclpy.shutdown()
+
+
+        if __name__ == '__main__':
+            main()
 
 **CMakeLists.txt**