Fixed Ticket 80. Added support for ElementTree Comments to be included by third party extensions when using cElementTree.

3 files changed, 48 insertions, 6 deletions

diff --git a/markdown/etree_loader.py b/markdown/etree_loader.py
index 0ea38f6..578fa28 100644
--- a/markdown/etree_loader.py
+++ b/markdown/etree_loader.py
@@ -8,26 +8,30 @@ def importETree():
     etree_in_c = None
     try: # Is it Python 2.5+ with C implemenation of ElementTree installed?
         import xml.etree.cElementTree as etree_in_c
+        from xml.etree.ElementTree import Comment
     except ImportError:
         try: # Is it Python 2.5+ with Python implementation of ElementTree?
             import xml.etree.ElementTree as etree
         except ImportError:
             try: # An earlier version of Python with cElementTree installed?
                 import cElementTree as etree_in_c
+                from elementtree.ElementTree import Comment
             except ImportError:
                 try: # An earlier version of Python with Python ElementTree?
                     import elementtree.ElementTree as etree
                 except ImportError:
                     message(CRITICAL, "Failed to import ElementTree")
                     sys.exit(1)
-    if etree_in_c and etree_in_c.VERSION < "1.0":
-        message(CRITICAL, "For cElementTree version 1.0 or higher is required.")
-        sys.exit(1)
-    elif etree_in_c :
+    if etree_in_c: 
+        if etree_in_c.VERSION < "1.0":
+            message(CRITICAL, "cElementTree version 1.0 or higher is required.")
+            sys.exit(1)
+        # Third party serializers (including ours) require non-c Comment
+        etree_in_c.Comment = Comment
         return etree_in_c
     elif etree.VERSION < "1.1":
-        message(CRITICAL, "For ElementTree version 1.1 or higher is required")
+        message(CRITICAL, "ElementTree version 1.1 or higher is required")
         sys.exit(1)
-    else :
+    else:
         return etree
 
diff --git a/markdown/util.py b/markdown/util.py
index f41469b..fa50e83 100644
--- a/markdown/util.py
+++ b/markdown/util.py
@@ -51,6 +51,8 @@ AUXILIARY GLOBAL FUNCTIONS
 
 def isBlockLevel(tag):
     """Check if the tag is a block level HTML tag."""
+    if tag is etree.Comment:
+        return True
     return BLOCK_LEVEL_ELEMENTS.match(tag)
 
 """
diff --git a/tests/test_apis.py b/tests/test_apis.py
index 51f4e73..114b09d 100644
--- a/tests/test_apis.py
+++ b/tests/test_apis.py
@@ -285,3 +285,39 @@ def _create_fake_extension(name, has_factory_func=True, is_wrong_type=False):
     # this needs to be specificly overriden or a new python session needs to 
     # be started to get rid of this. This should be ok in a testing context.
     sys.modules[mod_name] =  ext_mod
+
+
+class testETreeComments(unittest.TestCase):
+    """ 
+    Test that ElementTree Comments work.
+
+    These tests should only be a concern when using cElementTree with third
+    party serializers (including markdown's html4 serializer). While markdown
+    doesn't use ElementTree.Comment itself, we should certainly support any
+    third party extensions which may. Therefore, these tests are included to
+    ensure such support is maintained.
+    """
+
+    def setUp(self):
+        # Create comment node
+        self.comment = markdown.util.etree.Comment('foo')
+
+    def testCommentIsComment(self):
+        """ Test that an ElementTree Comment passes the `is Comment` test. """
+        self.assert_(self.comment.tag is markdown.util.etree.Comment)
+
+    def testCommentIsBlockLevel(self):
+        """ Test that an ElementTree Comment is recognized as BlockLevel. """
+        self.assert_(markdown.util.isBlockLevel(self.comment.tag))
+
+    def testCommentSerialization(self):
+        """ Test that an ElementTree Comment serializes properly. """
+        self.assertEqual(markdown.html4.to_html_string(self.comment),
+                    '<!--foo-->')
+
+    def testCommentPrettify(self):
+        """ Test that an ElementTree Comment is prettified properly. """
+        pretty = markdown.treeprocessors.PrettifyTreeprocessor()
+        pretty.run(self.comment)
+        self.assertEqual(markdown.html4.to_html_string(self.comment),
+                    '<!--foo-->\n')