dynamic_service.py

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#! /usr/bin/python
#
# This code is based on dynamic_action.py of the actionlib package, written by
# Eitan Marder-Eppstein.
# Adapted to work for services by Felix Widmaier at Synapticon GmbH.
#
# **********************************************************
#  Software License Agreement (BSD License)
#
#   Copyright (c) 2009, Willow Garage, Inc.
#   Copyright (c) 2018, Synapticon GmbH
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"""Helper class to load service message types."""
import roslib
import rospy
import sys
 
 
class DynamicService(object):
    """Provides types of the given service message."""
 
    def __init__(self, name):
        """Initialize.
 
        Args:
            name (str): Name of the service type (e.g. "std_srvs/SetBool").
 
        """
        self.name = name
        self.base = self.load_submsg('')
        self.request = self.load_submsg('Request')
        self.response = self.load_submsg('Response')
 
    def load_submsg(self, subname):
        """Load submessage.
 
        Args:
            subname (str): Suffix that is added to the type.
 
        Returns:
            The sub-message type.
 
        """
        msgclass = roslib.message.get_service_class(self.name + subname)
        if msgclass is None:
            rospy.logfatal('Could not load message for: %s' % (self.name +
                                                               subname))
            sys.exit(1)
        return msgclass