.. _ros_node_model:

ROS Node Model
==============

Within a Component, a **ROS Node** is represented by a **GenericDomainModel** with the following **Attributes.**

+-------------+---------------------+-------------------------------------------------+
| Attributes  | Value               | Description                                     |
+=============+=====================+=================================================+
| Type        | node                |                                                 |
+-------------+---------------------+-------------------------------------------------+
| Domain      | ros                 |                                                 |
+-------------+---------------------+-------------------------------------------------+
| Attribute 0 | *[ROS package]*     | ROS package name, *- e.g. "gazebo_ros"*         |
+-------------+---------------------+-------------------------------------------------+
| Attribute 1 | *[executable name]* | ROS node executable name *- e.g. "spawn_model"* |
+-------------+---------------------+-------------------------------------------------+
| Attribute 2 | *[output]*          | | *"screen"* - stdout/stderr to screen          |
|             |                     | | *"log"* - stdout/stderr to log file           |
+-------------+---------------------+-------------------------------------------------+
| Attribute 3 | *[launch-prefix]*   | Node's launch arguments *- e.g. "xterm -e"*     |
+-------------+---------------------+-------------------------------------------------+

If the CyPhy Master Interpreter is run, these Attributes will be used to populate
a node element in the generated ROS .launch file:

.. code-block:: none

  <node
    name=[GenericDomainModel name]
    pkg=[ROS package]
    type=[executable name]
    output=[output]
    launch-prefix=[launch-prefix]
  />

.. note::
   For a better understanding of the roslaunch XML node syntax, please consult its `documentation <http://wiki.ros.org/roslaunch/XML/node>`_

----

.. figure:: images/hexapod_leg_fsm_node_gdm_outside.png

  Hexapod Leg FSM Node GenericDomainModel (Outside)

.. figure:: images/hexapod_leg_fsm_node_gdm_attributes.png

  Hexapod Leg FSM Node GenericDomainModel (Attributes)

.. figure:: images/hexapod_leg_fsm_node_gdm_inside.png

  Hexapod Leg FSM Node GenericDomainModel (Inside)

----

A ROS Node Model GenericDomainModel may contain the following elements:

.. toctree::
   :maxdepth: 2

   ros_topic_publisher
   ros_service_server
   ros_action_server
   urdf_link_port
   parameter