subname enhanced ROS dynamic reconfigure server

dynamic_reconfigure_server2.py

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"""
Python client API for dynamic_reconfigure (L{DynamicReconfigureClient}) as well as 
example server implementation (L{DynamicReconfigureServer}).
"""

# This is an enhanced version of
# driver_common/dynamic_reconfigure/src/dynamic_reconfigure/server.py
# to support the "subname" parameter.

from __future__ import with_statement

import roslib; roslib.load_manifest('dynamic_reconfigure')
import rospy
import rosservice                  
import threading
import time
from dynamic_reconfigure import DynamicReconfigureCallbackException
from dynamic_reconfigure.srv import Reconfigure as ReconfigureSrv
from dynamic_reconfigure.msg import Config as ConfigMsg
from dynamic_reconfigure.msg import ConfigDescription as ConfigDescrMsg
from dynamic_reconfigure.msg import IntParameter, BoolParameter, StrParameter, DoubleParameter, ParamDescription
from dynamic_reconfigure.encoding import *

class Server(object):
    def __init__(self, type, callback, subname = None):
        self.mutex = threading.Lock()
        self.type = type
        self.config = type.defaults.copy() # (see https://code.ros.org/trac/ros/ticket/3394 )

        self.subname = subname
        if subname is None:
            self._prefix = '~'
        else:
            self._prefix = subname + '/'

        self.description = encode_description(type)
        self._copy_from_parameter_server()
        self.callback = callback
        self._clamp(self.config) 

        self.descr_topic = rospy.Publisher(self._prefix+'parameter_descriptions', ConfigDescrMsg, latch=True)
        self.descr_topic.publish(self.description);
        
        self.update_topic = rospy.Publisher(self._prefix+'parameter_updates', ConfigMsg, latch=True)
        self._change_config(self.config, type.all_level)
        
        self.set_service = rospy.Service(self._prefix+'set_parameters', ReconfigureSrv, self._set_callback)

    def update_configuration(self, changes):
        with self.mutex:
            new_config = dict(self.config)
            new_config.update(changes)
            self._clamp(new_config)
            return self._change_config(new_config, self._calc_level(new_config, self.config))

    def _copy_from_parameter_server(self):
        for param in self.type.config_description:
            try:
                self.config[param['name']] = rospy.get_param(self._prefix + param['name'])
            except KeyError:
                pass

    def _copy_to_parameter_server(self):
        for param in self.type.config_description:
            rospy.set_param(self._prefix + param['name'], self.config[param['name']])

    def _change_config(self, config, level):
        if self.subname != '':
            # call the callback with the subname
            self.config = self.callback(config, level, subname=self.subname)
        else:
            # backwards-compatible call to callback
            self.config = self.callback(config, level)
        if self.config is None:
            msg = 'Reconfigure callback should return a possibly updated configuration.'
            rospy.logerr(msg)
            raise DynamicReconfigureCallbackException(msg)
        
        self._copy_to_parameter_server()
        
        self.update_topic.publish(encode_config(self.config))

        return self.config
   
    def _calc_level(self, config1, config2):
        level = 0
        for param in self.type.config_description:
            if config1[param['name']] != config2[param['name']]:
                level |= param['level']

        return level

    def _clamp(self, config):
        for param in self.type.config_description: 
            maxval = self.type.max[param['name']] 
            minval = self.type.min[param['name']] 
            val = config[param['name']]
            if val > maxval and maxval != "": 
                config[param['name']] = maxval 
            elif val < minval and minval != "": 
                config[param['name']] = minval 

    def _set_callback(self, req):
        return encode_config(self.update_configuration(decode_config(req.config)))

dynamic_server.patch

--- dynamic_reconfigure/src/dynamic_reconfigure/server.py	2012-08-17 09:30:37.331027429 +0200
+++ /tmp/dynamic_reconfigure_server2.py	2012-08-17 09:26:57.360940524 +0200
@@ -35,6 +35,10 @@
 example server implementation (L{DynamicReconfigureServer}).
 """
 
+# This is an enhanced version of
+# driver_common/dynamic_reconfigure/src/dynamic_reconfigure/server.py
+# to support the "subname" parameter.
+
 from __future__ import with_statement
 
 import roslib; roslib.load_manifest('dynamic_reconfigure')
@@ -50,22 +54,29 @@
 from dynamic_reconfigure.encoding import *
 
 class Server(object):
-    def __init__(self, type, callback):
+    def __init__(self, type, callback, subname = None):
         self.mutex = threading.Lock()
         self.type = type
-        self.config = type.defaults
+        self.config = type.defaults.copy() # (see https://code.ros.org/trac/ros/ticket/3394 )
+
+        self.subname = subname
+        if subname is None:
+            self._prefix = '~'
+        else:
+            self._prefix = subname + '/'
+
         self.description = encode_description(type)
         self._copy_from_parameter_server()
         self.callback = callback
         self._clamp(self.config) 
 
-        self.descr_topic = rospy.Publisher('~parameter_descriptions', ConfigDescrMsg, latch=True)
+        self.descr_topic = rospy.Publisher(self._prefix+'parameter_descriptions', ConfigDescrMsg, latch=True)
         self.descr_topic.publish(self.description);
         
-        self.update_topic = rospy.Publisher('~parameter_updates', ConfigMsg, latch=True)
+        self.update_topic = rospy.Publisher(self._prefix+'parameter_updates', ConfigMsg, latch=True)
         self._change_config(self.config, type.all_level)
         
-        self.set_service = rospy.Service('~set_parameters', ReconfigureSrv, self._set_callback)
+        self.set_service = rospy.Service(self._prefix+'set_parameters', ReconfigureSrv, self._set_callback)
 
     def update_configuration(self, changes):
         with self.mutex:
@@ -77,16 +88,21 @@
     def _copy_from_parameter_server(self):
         for param in self.type.config_description:
             try:
-                self.config[param['name']] = rospy.get_param("~" + param['name'])
+                self.config[param['name']] = rospy.get_param(self._prefix + param['name'])
             except KeyError:
                 pass
 
     def _copy_to_parameter_server(self):
         for param in self.type.config_description:
-            rospy.set_param('~' + param['name'], self.config[param['name']])
+            rospy.set_param(self._prefix + param['name'], self.config[param['name']])
 
     def _change_config(self, config, level):
-        self.config = self.callback(config, level)
+        if self.subname != '':
+            # call the callback with the subname
+            self.config = self.callback(config, level, subname=self.subname)
+        else:
+            # backwards-compatible call to callback
+            self.config = self.callback(config, level)
         if self.config is None:
             msg = 'Reconfigure callback should return a possibly updated configuration.'
             rospy.logerr(msg)

For comparison with a recent question on answers.ros.org, I just updated this to include my code as a patch file against the original.