3 files changed, 54 insertions, 21 deletions

diff --git a/Lib/xml/sax/expatreader.py b/Lib/xml/sax/expatreader.py
index 341efd3..e3b3ad0 100644
--- a/Lib/xml/sax/expatreader.py
+++ b/Lib/xml/sax/expatreader.py
@@ -3,17 +3,6 @@ SAX driver for the Pyexpat C module.  This driver works with
 pyexpat.__version__ == '1.5'.
 """
 
-# Todo on driver:
-#  - make it support external entities (wait for pyexpat.c)
-#  - enable configuration between reset() and feed() calls
-#  - support lexical events?
-#  - proper inputsource handling
-#  - properties and features
-
-# Todo on pyexpat.c:
-#  - support XML_ExternalEntityParserCreate
-#  - exceptions in callouts from pyexpat to python code lose position info
-
 version = "0.20"
 
 from xml.sax._exceptions import *
@@ -30,10 +19,11 @@ class ExpatParser(xmlreader.IncrementalParser, xmlreader.Locator):
 
     def __init__(self, namespaceHandling=0, bufsize=2**16-20):
         xmlreader.IncrementalParser.__init__(self, bufsize)
-        self._source = None
+        self._source = xmlreader.InputSource()
         self._parser = None
         self._namespaces = namespaceHandling
         self._parsing = 0
+        self._entity_stack = []
 
     # XMLReader methods
 
@@ -186,11 +176,23 @@ class ExpatParser(xmlreader.IncrementalParser, xmlreader.Locator):
         self._dtd_handler.notationDecl(name, pubid, sysid)
 
     def external_entity_ref(self, context, base, sysid, pubid):
-        raise NotImplementedError()
         source = self._ent_handler.resolveEntity(pubid, sysid)
-        source = saxutils.prepare_input_source(source)
-        # FIXME: create new parser, stack self._source and self._parser
-        # FIXME: reuse code from self.parse(...)
+        source = saxutils.prepare_input_source(source,
+                                               self._source.getSystemId() or
+                                               "")
+        
+        self._entity_stack.append((self._parser, self._source))
+        self._parser = self._parser.ExternalEntityParserCreate(context)
+        self._source = source
+
+        try:
+            xmlreader.IncrementalParser.parse(self, source)
+            self.close()
+        except:
+            return 0  # FIXME: save error info here?
+
+        (self._parser, self._source) = self._entity_stack[-1]
+        del self._entity_stack[-1]
         return 1
         
 # ---
diff --git a/Lib/xml/sax/handler.py b/Lib/xml/sax/handler.py
index d25c171..c80457c 100644
--- a/Lib/xml/sax/handler.py
+++ b/Lib/xml/sax/handler.py
@@ -17,7 +17,7 @@ version = '2.0beta'
 #
 #============================================================================
 
-# ===== ErrorHandler =====
+# ===== ERRORHANDLER =====
 
 class ErrorHandler:
     """Basic interface for SAX error handlers. If you create an object
@@ -40,6 +40,7 @@ class ErrorHandler:
         "Handle a warning."   
         print exception
 
+        
 # ===== CONTENTHANDLER =====
 
 class ContentHandler:
@@ -199,7 +200,39 @@ class ContentHandler:
         http://xml.org/sax/features/external-general-entities and the
         http://xml.org/sax/features/external-parameter-entities
         properties."""
+
+        
+# ===== DTDHandler =====
+
+class DTDHandler:
+    """Handle DTD events.
+
+    This interface specifies only those DTD events required for basic
+    parsing (unparsed entities and attributes)."""
+
+    def notationDecl(self, name, publicId, systemId):
+	"Handle a notation declaration event."
+
+    def unparsedEntityDecl(self, name, publicId, systemId, ndata):
+	"Handle an unparsed entity declaration event."
+
+        
+# ===== ENTITYRESOLVER =====
         
+class EntityResolver:
+    """Basic interface for resolving entities. If you create an object
+    implementing this interface, then register the object with your
+    Parser, the parser will call the method in your object to
+    resolve all external entities. Note that DefaultHandler implements
+    this interface with the default behaviour."""
+    
+    def resolveEntity(self, publicId, systemId):
+	"""Resolve the system identifier of an entity and return either
+        the system identifier to read from as a string, or an InputSource
+        to read from."""
+	return systemId
+
+
 #============================================================================
 #
 # CORE FEATURES
diff --git a/Lib/xml/sax/xmlreader.py b/Lib/xml/sax/xmlreader.py
index e5133f6..04e7bc1 100644
--- a/Lib/xml/sax/xmlreader.py
+++ b/Lib/xml/sax/xmlreader.py
@@ -9,8 +9,8 @@ class XMLReader:
     
     def __init__(self):
         self._cont_handler = handler.ContentHandler()
-        #self._dtd_handler = handler.DTDHandler()
-        #self._ent_handler = handler.EntityResolver()
+        self._dtd_handler = handler.DTDHandler()
+        self._ent_handler = handler.EntityResolver()
         self._err_handler = handler.ErrorHandler()
 
     def parse(self, source):
@@ -109,8 +109,6 @@ class IncrementalParser(XMLReader):
         while buffer != "":
             self.feed(buffer)
             buffer = file.read(self._bufsize)
-            
-        self.reset()
 
     def feed(self, data):        
         """This method gives the raw XML data in the data parameter to