# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
import difflib
class HtmlSideBySideDiff(object):
table_tmpl = '''
<table class="side-by-side-diff">
<thead>
<th class="lineno"></th>
<th>%s</th>
<th class="lineno"></th>
<th>%s</th>
</thead>
%s
</table>
'''.strip()
line_tmpl = '''
<tr>
<td class="lineno">%s</td>
<td%s><pre>%s</pre></td>
<td class="lineno">%s</td>
<td%s><pre>%s</pre></td>
</tr>'''.strip()
def __init__(self, tabsize=4):
self._tabsize = tabsize
def _render_change(self, aline, bline, anum=None, bnum=None, astyle=None, bstyle=None):
astyle = (' class="%s"' % astyle) if astyle else ''
bstyle = (' class="%s"' % bstyle) if bstyle else ''
anum = anum if anum is not None else ''
bnum = bnum if bnum is not None else ''
return self.line_tmpl % (anum, astyle, aline, bnum, bstyle, bline)
def _preprocess(self, line):
if not line:
return line
line = line.expandtabs(self._tabsize)
return line.replace('&', '&').replace('<', '<').replace('>', '>')
def _replace_marks(self, line):
# if entire line was added/removed/changed
# we strip first mark and return corresponding flag
# this is needed to be able to highlight entire <td> in the table,
# rather then highlighting only chunk inside the <span>
flag = ''
if line.startswith('\0+') and line.endswith('\1'):
line = line.lstrip('\0+').rstrip('\1')
flag = 'diff-add'
elif line.startswith('\0-') and line.endswith('\1'):
line = line.lstrip('\0-').rstrip('\1')
flag = 'diff-rem'
elif '\0^' in line or '\0+' in line or '\0-' in line:
flag = 'diff-chg'
# replace all other marks with <span>'s
span = '<span class="%s">'
line = line.replace('\0+', span % 'diff-add')
line = line.replace('\0-', span % 'diff-rem')
line = line.replace('\0^', span % 'diff-chg')
line = line.replace('\1', '</span>')
return line, flag
def _make_line(self, diff):
aline, bline, changed = diff
if changed is None:
# context separation
return self._render_change('...', '...', '', '', 'diff-gap', 'diff-gap')
anum, aline = aline
bnum, bline = bline
aline = self._preprocess(aline)
bline = self._preprocess(bline)
if not changed:
# line doesn't changed - render with default style
return self._render_change(aline, bline, anum, bnum)
aline, aflag = self._replace_marks(aline)
bline, bflag = self._replace_marks(bline)
return self._render_change(aline, bline, anum, bnum, aflag, bflag)
def make_table(self, a, b, adesc=None, bdesc=None, context=5):
"""Make html table that displays side-by-side diff
Arguments:
- a -- list of text lines to be compared to b
- b -- list of text lines to be compared to a
- adesc -- description of the 'a' lines (e.g. filename)
- bdesc -- description of the 'b' lines (e.g. filename)
- context -- number of context lines to display
Uses difflib._mdiff function to generate diff.
"""
adesc = adesc or ''
bdesc = bdesc or ''
diff = difflib._mdiff(a, b, context=context)
lines = [self._make_line(d) for d in diff]
return self.table_tmpl % (adesc, bdesc, '\n'.join(lines))