Added PullDOM tree walker

tbroyer · tbroyer · commit e9db87b982f4 · 2007-05-26T13:03:21.000Z
--HG--
extra : convert_revision : svn%3Aacbfec75-9323-0410-a652-858a13e371e0/trunk%40614
diff --git a/src/treewalkers/pulldom.py b/src/treewalkers/pulldom.py
@@ -0,0 +1,46 @@
+from xml.dom.pulldom import START_ELEMENT, END_ELEMENT, \
+    COMMENT, IGNORABLE_WHITESPACE, CHARACTERS
+
+import _base
+
+from constants import voidElements
+
+class TreeWalker(_base.TreeWalker):
+    def walk(self, stream):
+        previous = None
+        for event in stream:
+            if previous is not None:
+                for token in self.tokens(previous, event):
+                    yield token
+            previous = event
+        for token in self.tokens(previous, None):
+            yield token
+    
+    def tokens(self, event, next):
+        type, node = event
+        if type == START_ELEMENT:
+            name = node.nodeName
+            if name in voidElements:
+                for token in self.emptyTag(name, \
+                  node.attributes.items(), not event or event[1] is not node):
+                    yield token
+            else:
+                yield self.startTag(name, node.attributes.items())
+        
+        elif type == END_ELEMENT:
+            name = node.nodeName
+            if name not in voidElements:
+                yield self.endTag(name)
+        
+        elif type == COMMENT:
+            yield self.comment(node.nodeValue)
+        
+        elif type in (IGNORABLE_WHITESPACE, CHARACTERS):
+            for token in self.text(node.nodeValue):
+                yield token
+        
+        else:
+            yield self.unknown(type)
+    
+    def walkChildren(self, node):
+        raise Exception(_("PullDOM tree walker's walkChildren should never be called"))
