Refactor graph generation and cover error path

Remove constants out of code and add error message to output when there
are no data produced by the show bgp ipv4/6 <prefix> command parser (or
BIRD equivalent - show route <prefix> all) and therefore no graph
can be generated. The error occures in situation when wrong prefix is
on input or the prefix has no paths in the routing table.

src/ulgbird.py

@@ -29,6 +29,9 @@ import defaults
 import ulgmodel
 import ulggraph
 
+STRING_BGP_GRAPH='BGP graph'
+STRING_BGP_GRAPH_ERROR='Error: Can not produce image out of the received output.'
+
 IPV46_SUBNET_REGEXP = '^[0-9a-fA-F:\.]+(/[0-9]{1,2}){0,1}$'
 RTNAME_REGEXP = '^[a-zA-Z0-9]+$'
 STRING_SYMBOL_ROUTING_TABLE = 'routing table'
@@ -357,7 +360,10 @@ class BirdGraphShowRouteAll(ulgmodel.TextCommand):
 
     def decorateResult(self,session,decorator_helper=None):
         if(session.isFinished()):
-            return (decorator_helper.img(decorator_helper.getSpecialContentURL(session.getSessionId()),"BGP graph"),1)
+            if(session.getData() != None) and (session.getData() != []):
+                return (decorator_helper.img(decorator_helper.getSpecialContentURL(session.getSessionId()),STRING_BGP_GRAPH),1)
+            else:
+                return (STRING_BGP_GRAPH_ERROR, 1)
         else:
             return ('',0)
 

src/ulgcisco.py

@@ -31,6 +31,8 @@ import ulgmodel
 import ulggraph
 
 # module globals
+STRING_BGP_GRAPH='BGP graph'
+STRING_BGP_GRAPH_ERROR='Error: Can not produce image out of the received output.'
 STRING_EXPECT_SSH_NEWKEY='Are you sure you want to continue connecting'
 STRING_EXPECT_PASSWORD='(P|p)assword:'
 STRING_EXPECT_SHELL_PROMPT_REGEXP = '\n[a-zA-Z0-9\._-]+>'
@@ -600,7 +602,10 @@ class CiscoCommandGraphShowBgpIPv46Uni(ulgmodel.TextCommand):
 
     def decorateResult(self,session,decorator_helper=None):
         if(session.isFinished()):
-		return (decorator_helper.img(decorator_helper.getSpecialContentURL(session.getSessionId()),"BGP graph"),1)
+		if(session.getData() != None) and (session.getData() != []):
+			return (decorator_helper.img(decorator_helper.getSpecialContentURL(session.getSessionId()),STRING_BGP_GRAPH),1)
+		else:
+			return (STRING_BGP_GRAPH_ERROR, 1)
 	else:
 		return ('',0)
 
@@ -609,6 +614,7 @@ class CiscoCommandGraphShowBgpIPv46Uni(ulgmodel.TextCommand):
 
     def getSpecialContent(self,session,**params):
         paths = session.getData()
+	ulgmodel.debug("CISCO GRAPH: "+str(paths))
         print "Content-type: image/png\n"
         ulggraph.bgp_graph_gen(reduce_bgp_paths(paths),start=session.getRouter().getName(),
 			       end=session.getParameters()[0])