added samples to README, exception handling

README.md

@@ -58,3 +58,42 @@ Dependencies
 ===========
 * simplejson 
 * pika
+
+Usage
+=========
+
+This is what you normally want to do when writing a new genericore module:
+
+    conf = gen.Configurator(PROTO_VERSION,DESCRIPTION)  
+    amqp = gen.auto_amqp()   
+    s = YourMagic()  
+
+    conf.configure([amqp,s])    #set up parser and eval parsed stuff
+
+    # start network connections, probably also for your Parser (e.g. backend)
+    amqp.create_connection()
+
+    def cb (ch,method,header,body):
+      entry = s.process(json.loads(body))
+      amqp.publish(json.dumps(entry))
+
+    amqp.consume(cb)
+    amqp.start_loop()
+
+Configurator
+===========
+python-genericore provides the Configurator class which can be instanciated
+in order to do all your nasty configuration and argument parsing stuff.
+
+In order to configure YOUR Object object you may want to do the following
+things:
+* derive your class from Configurable ( to have the load\_conf magic )
+  a "config" member variable is now available with the config dictionary
+* implement populate\_parser(parser)
+  in this function you can add custom arguments to the command line parser
+  (argparse is the weaopn of choice in Configurator)
+* implement eval\_parser(args)
+  do something with the then parsed arguments
+
+These functions will be called by the Configurator when doing a configure
+for a list of modules (including your's)

genericore/utils.py

@@ -39,7 +39,7 @@ def load_conf_parser(self,parser):
       """ loads the configuration from a parser object """
 
 class Configurator(Configurable):
-  def __init__(self,PROTO_VERSION,DESCRIPTION,conf=None):
+  def __init__(self,PROTO_VERSION=1,DESCRIPTION='description not set!',conf=None):
     """ PROTO_VERSION is the protocol version of the module to configure """
     Configurable.__init__(self,conf)
     self.PROTO_VERSION = PROTO_VERSION
@@ -59,14 +59,17 @@ def configure(self,conf_list):
 
     self.populate_parser(parser)
     for configurable in conf_list:
-      configurable.populate_parser(parser)
+      try: configurable.populate_parser(parser) 
+      except : log.warning(str(configurable.__class__) + "does not have populate_parser")
 
     args = parser.parse_args()
 
     self.eval_parser(args)
     for i in conf_list:
-      i.load_conf(self.config)
-      i.eval_parser(args)
+      try:
+        i.load_conf(self.config)
+        i.eval_parser(args)
+      except Exception as e: log.warning(str(i.__class__) + "does not have eval_parser or load_conf" + str(e))
 
     self.blend(conf_list)
     log.debug ('New Configuration:' + str(self.config))