--- a/sbsv2/raptor/python/filter_interface.py	Mon Nov 16 09:46:46 2009 +0000
+++ b/sbsv2/raptor/python/filter_interface.py	Mon Nov 16 20:39:37 2009 +0000
@@ -18,7 +18,7 @@
 
 class Filter(object):
 	
-	def open(self, raptor):
+	def open(self, params):
 		return False
 	
 	def write(self, text):
@@ -32,3 +32,87 @@
 	
 	def formatError(self, message):
 		return "sbs: error: " + message + "\n"
+		
+
+import sys
+import xml.sax
+
+class FilterSAX(Filter, xml.sax.handler.ContentHandler, xml.sax.handler.ErrorHandler):
+	"base class for filters using a SAX parser"
+	
+	# define these methods in your subclass
+	
+	def startDocument(self):
+		"called once before any elements are seen"
+		pass
+		
+	def startElement(self, name, attributes):
+		"called on the opening of any element"
+		pass
+	
+	def characters(self, char):
+		"called one or more times with body text from an element"
+		pass
+		
+	def endElement(self, name):
+		"called on the closing of any element"
+		pass
+	
+	def endDocument(self):
+		"called once when all elements are closed"
+		pass
+
+	def error(self, exception):
+		"the parse found an error which is (possibly) recoverable"
+		pass
+		
+	def fatalError(self, exception):
+		"the parser thinks an error occurred which should stop everything"
+		pass
+		
+	def warning(self, exception):
+		"the parser found something to complain about that might not matter"
+		pass
+		
+	# these methods are from the Filter base class
+	
+	def open(self, params):
+		"initialise"
+		
+		self.params = params
+		self.ok = True
+		try:
+			self.parser = xml.sax.make_parser(['xml.sax.expatreader'])
+			self.parser.setContentHandler(self)
+			self.parser.setErrorHandler(self)
+			
+		except Exception, ex:
+			sys.stderr.write(self.formatError(str(ex)))
+			self.ok = False
+		
+		return self.ok
+	
+		
+	def write(self, text):
+		"process some log text"
+		try:
+			self.parser.feed(text)
+		except Exception, ex:
+			sys.stderr.write(self.formatError(str(ex)))
+			self.ok = False
+				
+		return self.ok
+	
+
+	def close(self):
+		"finish off"
+		try:
+			self.parser.close()
+		except Exception, ex:
+			sys.stderr.write(self.formatError(str(ex)))
+			self.ok = False
+			
+		return self.ok
+	
+
+# the end