bpo-36673: Implement comment/PI parsing support for the TreeBuilder in ElementTree. (#12883)
* bpo-36673: Implement comment/PI parsing support for the TreeBuilder in ElementTree.
* bpo-36673: Rewrite the comment/PI factory handling for the TreeBuilder in "_elementtree" to make it use the same factories as the ElementTree module, and to make it explicit when the comments/PIs are inserted into the tree and when they are not (which is the default).
diff --git a/Lib/xml/etree/ElementTree.py b/Lib/xml/etree/ElementTree.py
index c9e2f36..c640048 100644
--- a/Lib/xml/etree/ElementTree.py
+++ b/Lib/xml/etree/ElementTree.py
@@ -1374,12 +1374,30 @@
*element_factory* is an optional element factory which is called
to create new Element instances, as necessary.
+ *comment_factory* is a factory to create comments to be used instead of
+ the standard factory. If *insert_comments* is false (the default),
+ comments will not be inserted into the tree.
+
+ *pi_factory* is a factory to create processing instructions to be used
+ instead of the standard factory. If *insert_pis* is false (the default),
+ processing instructions will not be inserted into the tree.
"""
- def __init__(self, element_factory=None):
+ def __init__(self, element_factory=None, *,
+ comment_factory=None, pi_factory=None,
+ insert_comments=False, insert_pis=False):
self._data = [] # data collector
self._elem = [] # element stack
self._last = None # last element
+ self._root = None # root element
self._tail = None # true if we're after an end tag
+ if comment_factory is None:
+ comment_factory = Comment
+ self._comment_factory = comment_factory
+ self.insert_comments = insert_comments
+ if pi_factory is None:
+ pi_factory = ProcessingInstruction
+ self._pi_factory = pi_factory
+ self.insert_pis = insert_pis
if element_factory is None:
element_factory = Element
self._factory = element_factory
@@ -1387,8 +1405,8 @@
def close(self):
"""Flush builder buffers and return toplevel document Element."""
assert len(self._elem) == 0, "missing end tags"
- assert self._last is not None, "missing toplevel element"
- return self._last
+ assert self._root is not None, "missing toplevel element"
+ return self._root
def _flush(self):
if self._data:
@@ -1417,6 +1435,8 @@
self._last = elem = self._factory(tag, attrs)
if self._elem:
self._elem[-1].append(elem)
+ elif self._root is None:
+ self._root = elem
self._elem.append(elem)
self._tail = 0
return elem
@@ -1435,6 +1455,33 @@
self._tail = 1
return self._last
+ def comment(self, text):
+ """Create a comment using the comment_factory.
+
+ *text* is the text of the comment.
+ """
+ return self._handle_single(
+ self._comment_factory, self.insert_comments, text)
+
+ def pi(self, target, text=None):
+ """Create a processing instruction using the pi_factory.
+
+ *target* is the target name of the processing instruction.
+ *text* is the data of the processing instruction, or ''.
+ """
+ return self._handle_single(
+ self._pi_factory, self.insert_pis, target, text)
+
+ def _handle_single(self, factory, insert, *args):
+ elem = factory(*args)
+ if insert:
+ self._flush()
+ self._last = elem
+ if self._elem:
+ self._elem[-1].append(elem)
+ self._tail = 1
+ return elem
+
# also see ElementTree and TreeBuilder
class XMLParser:
@@ -1519,6 +1566,15 @@
def handler(prefix, event=event_name, append=append):
append((event, None))
parser.EndNamespaceDeclHandler = handler
+ elif event_name == 'comment':
+ def handler(text, event=event_name, append=append, self=self):
+ append((event, self.target.comment(text)))
+ parser.CommentHandler = handler
+ elif event_name == 'pi':
+ def handler(pi_target, data, event=event_name, append=append,
+ self=self):
+ append((event, self.target.pi(pi_target, data)))
+ parser.ProcessingInstructionHandler = handler
else:
raise ValueError("unknown event %r" % event_name)
@@ -1640,7 +1696,10 @@
# (see tests)
_Element_Py = Element
- # Element, SubElement, ParseError, TreeBuilder, XMLParser
+ # Element, SubElement, ParseError, TreeBuilder, XMLParser, _set_factories
from _elementtree import *
+ from _elementtree import _set_factories
except ImportError:
pass
+else:
+ _set_factories(Comment, ProcessingInstruction)