add new utility module for html processing

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@3567 fd906abe-77d9-0310-91a1-e0d9ade77398
2009-10-05 21:00:50 +00:00 · 2009-10-05 21:00:50 +00:00 · 427d043f2c
commit 427d043f2c
parent 0bb7071829
3 changed files with 84 additions and 0 deletions
--- a/util/html.py
+++ b/util/html.py
@ -0,0 +1,63 @@
+#
+#  Copyright (c) 2009 Helmut Merz helmutm@cy55.de
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software
+#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+
+"""
+Strip HTML tags and other HTML-related utilities.
+
+$Id$
+"""
+
+from cybertools.text.lib.BeautifulSoup import BeautifulSoup, Comment
+
+#validTags = 'p i strong b u a h1 h2 h3 img pre br'.split()
+validTags = 'b br div em font h1 h2 h3 i p pre span strong table td tr u'.split()
+
+#validAttrs = 'href src'.split()
+validAttrs = 'class style'.split()
+
+validStyles = 'font-style font-weight'.split()
+
+
+def sanitize(value, validTags=validTags, validAttrs=validAttrs,
+                    validStyles=validStyles):
+    soup = BeautifulSoup(value)
+    for comment in soup.findAll(text=lambda text: isinstance(text, Comment)):
+        comment.extract()
+    for tag in soup.findAll(True):
+        if tag.name not in validTags:
+            tag.hidden = True
+        attrs = []
+        for attr, val in tag.attrs:
+            if attr not in validAttrs:
+                continue
+            if attr == 'style':
+                val = sanitizeStyle(val, validStyles)
+            if val:
+                attrs.append((attr, val))
+        tag.attrs = attrs
+    return soup.renderContents().decode('utf8')
+
+
+def sanitizeStyle(value, validStyles=validStyles):
+    result = []
+    for item in value.split(';'):
+        if ':' in item:
+            k, v = item.split(':')
+            if k.strip() in validStyles:
+                result.append(item.strip())
+    return '; '.join(result)
--- a/util/html.txt
+++ b/util/html.txt
@ -0,0 +1,20 @@
+==================
+Tweaking HTML text
+==================
+
+$Id$
+
+  >>> from cybertools.util.html import sanitize
+
+  >>> input = """<html>
+  ... <p class="standard" style="font-size: 200%; font-weight: bold">
+  ...   <a href="blubb"><b>Text</b></a>
+  ... </p>
+  ... </html>"""
+
+  >>> sanitize(input, validAttrs=['style'])
+  u'\n<p style="font-weight: bold">\n<b>Text</b>\n</p>\n'
+
+  >>> sanitize(input, ['p', 'b'], ['class'])
+  u'\n<p class="standard">\n<b>Text</b>\n</p>\n'
+
--- a/util/tests.py
+++ b/util/tests.py
@ -24,6 +24,7 @@ def test_suite():
        doctest.DocFileSuite('config.txt', optionflags=flags),
        doctest.DocFileSuite('defer.txt', optionflags=flags),
        doctest.DocFileSuite('format.txt', optionflags=flags),
+        doctest.DocFileSuite('html.txt', optionflags=flags),
        doctest.DocFileSuite('multikey.txt', optionflags=flags),
        doctest.DocFileSuite('property.txt', optionflags=flags),
        doctest.DocFileSuite('json.txt', optionflags=flags),