.. _Server ROS:

ROS Service Server
====================

The Follow Along Examples:

- :ref:`Command ROS`
- :ref:`Server ROS` <- you are here 
- :ref:`Client ROS`

.. raw:: html
    
    <div style="background: #C3F8FF" class="admonition note custom">
        <p style="background: light-blue" class="admonition-title">
            Follow along: ROS Service Server Example
        </p>
        <div class="line-block">
            <div class="line">The program launching process along with parameter settings are all simplified and set up on the Jupyter Notebook Environment.</div>
        </div>
        <ul>
            <li>Open the 02_02_ros_service_client.ipynb Jupyter Notebook</li>
            <li>Import the necessary python libraries and modules</li>
            <li>Follow and Execute the example codes</li>

        </ul>
        <div class="line">(The Jetson Board used for these examples are => Jetson Nano)</div>
        
    </div>


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    <hr>

Open the following jupyter notebook:

-   02_02_ros_service_client.ipynb
-   To run the cells within the notebook use *Ctrl + Enter*

.. thumbnail:: /_images/robot_control_move/comm12.png

.. thumbnail:: /_images/robot_control_move/comm13.png


-   Import print_function from __future__ module for Python3 compatibility
-   Import sys module
-   Import rospy_tutorials.srv module
-   Import rospy modules

.. code-block:: python

    from __future__ import print_function
    import sys
    import rospy
    from rospy_tutorials.srv import *
    

-   Create add_two_ints_client()  function
-   Create add_two_ints_client() 
-   Get add_two_ints Service result
-   exception handling


.. code-block:: python

    def add_two_ints_client(x, y):
        rospy.wait_for_service('add_two_ints')
        try:
            add_two_ints = rospy.ServiceProxy('add_two_ints', AddTwoInts)
            resp1 = add_two_ints(x, y)
            return resp1.sum
        except rospy.ServiceException as e:
            print("Service call failed: %s"%e)

-   Get user input x, y, and output the calculation result:

.. code-block:: python

    def usage():
        return "%s [x y]"%sys.argv[0]

.. code-block:: python

    input_num = input("숫자 두 개를 입력하세요(ex: a,b) : ")
    x = int(input_num[0])
    y = int(input_num[1])
    print("Requesting %s+%s"%(x, y))
    print("%s + %s = %s"%(x, y, add_two_ints_client(x, y)))