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[Docutils-checkins] r4641 - in trunk/docutils: docutils/nodes.py test/test_traversals.py
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From: <bl...@us...> - 2006-06-28 16:28:06
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Author: blais
Date: 2006-06-28 18:27:55 +0200 (Wed, 28 Jun 2006)
New Revision: 4641
Added:
trunk/docutils/test/test_traversals.py
Modified:
trunk/docutils/docutils/nodes.py
Log:
Added StopTraversal exception in nodes, to interrupt the traversal cleanly.
I needed this for my Nabu presentation layer, in order to be able to render
just the first portion of my blog entries.
Modified: trunk/docutils/docutils/nodes.py
===================================================================
--- trunk/docutils/docutils/nodes.py 2006-06-27 13:18:32 UTC (rev 4640)
+++ trunk/docutils/docutils/nodes.py 2006-06-28 16:27:55 UTC (rev 4641)
@@ -113,22 +113,31 @@
Parameter `visitor`: A `NodeVisitor` object, containing a
``visit`` implementation for each `Node` subclass encountered.
+
+ Return true if we should stop the traversal.
"""
+ stop = 0
visitor.document.reporter.debug(
'docutils.nodes.Node.walk calling dispatch_visit for %s'
% self.__class__.__name__)
try:
- visitor.dispatch_visit(self)
- except (SkipChildren, SkipNode):
- return
- except SkipDeparture: # not applicable; ignore
- pass
- children = self.children
- try:
- for child in children[:]:
- child.walk(visitor)
- except SkipSiblings:
- pass
+ try:
+ visitor.dispatch_visit(self)
+ except (SkipChildren, SkipNode):
+ return stop
+ except SkipDeparture: # not applicable; ignore
+ pass
+ children = self.children
+ try:
+ for child in children[:]:
+ if child.walk(visitor):
+ stop = 1
+ break
+ except SkipSiblings:
+ pass
+ except StopTraversal:
+ stop = 1
+ return stop
def walkabout(self, visitor):
"""
@@ -139,8 +148,11 @@
Parameter `visitor`: A `NodeVisitor` object, containing a
``visit`` and ``depart`` implementation for each `Node`
subclass encountered.
+
+ Return true if we should stop the traversal.
"""
call_depart = 1
+ stop = 0
visitor.document.reporter.debug(
'docutils.nodes.Node.walkabout calling dispatch_visit for %s'
% self.__class__.__name__)
@@ -148,22 +160,27 @@
try:
visitor.dispatch_visit(self)
except SkipNode:
- return
+ return stop
except SkipDeparture:
call_depart = 0
children = self.children
try:
for child in children[:]:
- child.walkabout(visitor)
+ if child.walkabout(visitor):
+ stop = 1
+ break
except SkipSiblings:
pass
except SkipChildren:
pass
+ except StopTraversal:
+ stop = 1
if call_depart:
visitor.document.reporter.debug(
'docutils.nodes.Node.walkabout calling dispatch_departure '
'for %s' % self.__class__.__name__)
visitor.dispatch_departure(self)
+ return stop
def traverse(self, condition=None,
include_self=1, descend=1, siblings=0, ascend=0):
@@ -1692,6 +1709,19 @@
pass
+class StopTraversal(TreePruningException):
+
+ """
+ Stop the traversal alltogether. The current node's ``depart_...`` method
+ is not affected. The parent nodes ``depart_...`` methods are also called
+ as usual. No other nodes are visited. This is an alternative to
+ NodeFound that does not cause exception handling to trickle up to the
+ caller.
+ """
+
+ pass
+
+
def make_id(string):
"""
Convert `string` into an identifier and return it.
Added: trunk/docutils/test/test_traversals.py
===================================================================
--- trunk/docutils/test/test_traversals.py 2006-06-27 13:18:32 UTC (rev 4640)
+++ trunk/docutils/test/test_traversals.py 2006-06-28 16:27:55 UTC (rev 4641)
@@ -0,0 +1,75 @@
+#! /usr/bin/env python
+
+# $Id$
+# Author: Martin Blais <bl...@fu...>
+# Copyright: This module has been placed in the public domain.
+
+"""
+Test module for traversals.
+"""
+
+import unittest
+import DocutilsTestSupport # must be imported before docutils
+from docutils import nodes, core, io, utils, writers
+from docutils.writers.null import Writer as NullWriter
+import docutils
+
+
+
+stop_traversal_input = '''
+==================
+ Train Travel
+==================
+
+Happily, happily going by train.
+
+.. attention:: Attention, attention. This is a public annoucement.
+ You must get off the train now.
+
+KaZoom! Train crashes.
+
+- Told ya!!! Get off the train next time.
+
+'''
+
+class AttentiveVisitor(nodes.SparseNodeVisitor):
+
+ def visit_attention(self, node):
+ raise nodes.StopTraversal
+
+ def visit_bullet_list(self, node):
+ raise RuntimeError("It's too late for attention, "
+ "more discipline is needed!.")
+
+class AttentiveWriter(writers.Writer):
+
+ def translate(self):
+ self.visitor = visitor = AttentiveVisitor(self.document)
+
+ # Test both kinds of traversals.
+ self.document.walkabout(visitor)
+ self.document.walk(visitor)
+
+class StopTraversalTests(unittest.TestCase, docutils.SettingsSpec):
+ """
+ Test interrupting the visitor during traversal. In this test we stop it
+ when we reach an attention node.
+ """
+ def test_stop_traversal(self):
+ # Load some document tree in memory.
+ doctree = docutils.core.publish_doctree(
+ source=stop_traversal_input,
+ reader_name='standalone',
+ parser_name='restructuredtext',
+ settings_spec=self)
+ self.assert_(isinstance(doctree, nodes.document))
+
+ parts = docutils.core.publish_parts(
+ reader_name='doctree', source_class=docutils.io.DocTreeInput,
+ source=doctree, source_path='test',
+ writer=AttentiveWriter())
+
+
+if __name__ == '__main__':
+ unittest.main()
+
Property changes on: trunk/docutils/test/test_traversals.py
___________________________________________________________________
Name: svn:executable
+ *
Name: svn:keywords
+ Author Date Id Revision
Name: svn:eol-style
+ native
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