Mercurial > genshi > mirror
annotate markup/filters.py @ 69:c40a5dcd2b55 trunk
A couple of minor performance improvements.
| author | cmlenz |
|---|---|
| date | Mon, 10 Jul 2006 17:37:01 +0000 |
| parents | 59eb24184e9c |
| children | 01d36818bb3d |
| rev | line source |
|---|---|
| 1 | 1 # -*- coding: utf-8 -*- |
| 2 # | |
|
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59eb24184e9c
Switch copyright to Edgewall and URLs to markup.edgewall.org.
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3 # Copyright (C) 2006 Edgewall Software |
| 1 | 4 # All rights reserved. |
| 5 # | |
| 6 # This software is licensed as described in the file COPYING, which | |
| 7 # you should have received as part of this distribution. The terms | |
|
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Switch copyright to Edgewall and URLs to markup.edgewall.org.
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8 # are also available at http://markup.edgewall.org/wiki/License. |
| 1 | 9 # |
| 10 # This software consists of voluntary contributions made by many | |
| 11 # individuals. For the exact contribution history, see the revision | |
|
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Switch copyright to Edgewall and URLs to markup.edgewall.org.
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12 # history and logs, available at http://markup.edgewall.org/log/. |
| 1 | 13 |
| 14 """Implementation of a number of stream filters.""" | |
| 15 | |
| 16 try: | |
| 17 frozenset | |
| 18 except NameError: | |
| 19 from sets import ImmutableSet as frozenset | |
| 20 import re | |
| 21 | |
| 69 | 22 from markup.core import Attributes, Markup, Namespace |
| 23 from markup.core import END, END_NS, START, START_NS, TEXT | |
| 1 | 24 from markup.path import Path |
| 25 | |
|
17
74cc70129d04
Refactoring to address #6: all match templates are now processed by a single filter, which means that match templates added by included templates are properly applied. A side effect of this refactoring is that `Context` objects may not be reused across multiple template processing runs.
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26 __all__ = ['IncludeFilter', 'WhitespaceFilter', 'HTMLSanitizer'] |
| 1 | 27 |
| 28 | |
| 29 class IncludeFilter(object): | |
| 30 """Template filter providing (very) basic XInclude support | |
| 31 (see http://www.w3.org/TR/xinclude/) in templates. | |
| 32 """ | |
| 33 | |
|
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5420cfe42d36
Actually make use of the `markup.core.Namespace` class, and add a couple of doctests.
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34 NAMESPACE = Namespace('http://www.w3.org/2001/XInclude') |
| 1 | 35 |
|
17
74cc70129d04
Refactoring to address #6: all match templates are now processed by a single filter, which means that match templates added by included templates are properly applied. A side effect of this refactoring is that `Context` objects may not be reused across multiple template processing runs.
cmlenz
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36 def __init__(self, loader): |
| 1 | 37 """Initialize the filter. |
| 38 | |
| 39 @param loader: the `TemplateLoader` to use for resolving references to | |
| 40 external template files | |
| 41 """ | |
| 42 self.loader = loader | |
| 43 | |
|
12
97423376736e
Make the XInclude filter track namespace context, to enable it to omit `END_NS` events for the XInclude namespace.
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44 def __call__(self, stream, ctxt=None, ns_prefixes=None): |
| 1 | 45 """Filter the stream, processing any XInclude directives it may |
| 46 contain. | |
| 47 | |
| 48 @param ctxt: the template context | |
| 49 @param stream: the markup event stream to filter | |
| 50 """ | |
|
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97423376736e
Make the XInclude filter track namespace context, to enable it to omit `END_NS` events for the XInclude namespace.
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51 from markup.template import Template, TemplateError, TemplateNotFound |
| 1 | 52 |
|
12
97423376736e
Make the XInclude filter track namespace context, to enable it to omit `END_NS` events for the XInclude namespace.
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53 if ns_prefixes is None: |
|
97423376736e
Make the XInclude filter track namespace context, to enable it to omit `END_NS` events for the XInclude namespace.
cmlenz
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diff
changeset
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54 ns_prefixes = [] |
| 1 | 55 in_fallback = False |
| 56 include_href, fallback_stream = None, None | |
| 69 | 57 namespace = self.NAMESPACE |
| 1 | 58 |
| 59 for kind, data, pos in stream: | |
| 60 | |
| 69 | 61 if kind is START and not in_fallback and data[0] in namespace: |
| 1 | 62 tag, attrib = data |
| 63 if tag.localname == 'include': | |
| 64 include_href = attrib.get('href') | |
| 65 elif tag.localname == 'fallback': | |
| 66 in_fallback = True | |
| 67 fallback_stream = [] | |
| 68 | |
| 69 | 69 elif kind is END and data in namespace: |
| 1 | 70 if data.localname == 'include': |
| 71 try: | |
| 72 if not include_href: | |
| 73 raise TemplateError('Include misses required ' | |
| 74 'attribute "href"') | |
|
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b4d17897d053
* Include paths are now interpreted relative to the path of the including template. Closes #3.
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75 template = self.loader.load(include_href, |
|
b4d17897d053
* Include paths are now interpreted relative to the path of the including template. Closes #3.
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76 relative_to=pos[0]) |
|
17
74cc70129d04
Refactoring to address #6: all match templates are now processed by a single filter, which means that match templates added by included templates are properly applied. A side effect of this refactoring is that `Context` objects may not be reused across multiple template processing runs.
cmlenz
parents:
15
diff
changeset
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77 for event in template.generate(ctxt): |
|
74cc70129d04
Refactoring to address #6: all match templates are now processed by a single filter, which means that match templates added by included templates are properly applied. A side effect of this refactoring is that `Context` objects may not be reused across multiple template processing runs.
cmlenz
parents:
15
diff
changeset
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78 yield event |
|
13
f9001cd6785b
Match directives should now also be applied when included indirectly.
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79 |
| 1 | 80 except TemplateNotFound: |
| 81 if fallback_stream is None: | |
| 82 raise | |
| 83 for event in fallback_stream: | |
| 84 yield event | |
| 85 | |
| 86 include_href = None | |
| 87 fallback_stream = None | |
|
17
74cc70129d04
Refactoring to address #6: all match templates are now processed by a single filter, which means that match templates added by included templates are properly applied. A side effect of this refactoring is that `Context` objects may not be reused across multiple template processing runs.
cmlenz
parents:
15
diff
changeset
|
88 |
| 1 | 89 elif data.localname == 'fallback': |
| 90 in_fallback = False | |
| 91 | |
| 92 elif in_fallback: | |
| 93 fallback_stream.append((kind, data, pos)) | |
| 94 | |
| 69 | 95 elif kind is START_NS and data[1] == namespace: |
|
12
97423376736e
Make the XInclude filter track namespace context, to enable it to omit `END_NS` events for the XInclude namespace.
cmlenz
parents:
10
diff
changeset
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96 ns_prefixes.append(data[0]) |
|
97423376736e
Make the XInclude filter track namespace context, to enable it to omit `END_NS` events for the XInclude namespace.
cmlenz
parents:
10
diff
changeset
|
97 |
| 69 | 98 elif kind is END_NS and data in ns_prefixes: |
|
12
97423376736e
Make the XInclude filter track namespace context, to enable it to omit `END_NS` events for the XInclude namespace.
cmlenz
parents:
10
diff
changeset
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99 ns_prefixes.pop() |
| 1 | 100 |
| 101 else: | |
| 102 yield kind, data, pos | |
| 103 | |
| 104 | |
| 105 class WhitespaceFilter(object): | |
| 106 """A filter that removes extraneous white space from the stream. | |
| 107 | |
| 69 | 108 TODO: |
| 1 | 109 * Support for xml:space |
| 110 """ | |
| 111 _TRAILING_SPACE = re.compile('[ \t]+(?=\n)') | |
| 112 _LINE_COLLAPSE = re.compile('\n{2,}') | |
| 113 | |
| 114 def __call__(self, stream, ctxt=None): | |
| 69 | 115 trim_trailing_space = self._TRAILING_SPACE.sub |
| 116 collapse_lines = self._LINE_COLLAPSE.sub | |
| 117 mjoin = Markup('').join | |
| 118 | |
| 1 | 119 textbuf = [] |
| 120 for kind, data, pos in stream: | |
| 69 | 121 if kind is TEXT: |
| 1 | 122 textbuf.append(data) |
| 69 | 123 else: |
| 124 if textbuf: | |
| 125 text = mjoin(textbuf, escape_quotes=False) | |
| 126 text = trim_trailing_space('', text) | |
| 127 text = collapse_lines('\n', text) | |
| 128 yield TEXT, Markup(text), pos | |
| 129 del textbuf[:] | |
| 1 | 130 yield kind, data, pos |
| 69 | 131 else: |
| 132 if textbuf: | |
| 133 text = mjoin(textbuf, escape_quotes=False) | |
| 134 text = trim_trailing_space('', text) | |
| 135 text = collapse_lines('\n', text) | |
| 136 yield TEXT, Markup(text), pos | |
| 1 | 137 |
| 138 | |
| 139 class HTMLSanitizer(object): | |
| 140 """A filter that removes potentially dangerous HTML tags and attributes | |
| 141 from the stream. | |
| 142 """ | |
| 143 | |
| 144 _SAFE_TAGS = frozenset(['a', 'abbr', 'acronym', 'address', 'area', 'b', | |
| 145 'big', 'blockquote', 'br', 'button', 'caption', 'center', 'cite', | |
| 146 'code', 'col', 'colgroup', 'dd', 'del', 'dfn', 'dir', 'div', 'dl', 'dt', | |
| 147 'em', 'fieldset', 'font', 'form', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', | |
| 148 'hr', 'i', 'img', 'input', 'ins', 'kbd', 'label', 'legend', 'li', 'map', | |
| 149 'menu', 'ol', 'optgroup', 'option', 'p', 'pre', 'q', 's', 'samp', | |
| 150 'select', 'small', 'span', 'strike', 'strong', 'sub', 'sup', 'table', | |
| 151 'tbody', 'td', 'textarea', 'tfoot', 'th', 'thead', 'tr', 'tt', 'u', | |
| 152 'ul', 'var']) | |
| 153 | |
| 154 _SAFE_ATTRS = frozenset(['abbr', 'accept', 'accept-charset', 'accesskey', | |
| 15 | 155 'action', 'align', 'alt', 'axis', 'bgcolor', 'border', 'cellpadding', |
| 1 | 156 'cellspacing', 'char', 'charoff', 'charset', 'checked', 'cite', 'class', |
| 157 'clear', 'cols', 'colspan', 'color', 'compact', 'coords', 'datetime', | |
| 158 'dir', 'disabled', 'enctype', 'for', 'frame', 'headers', 'height', | |
| 159 'href', 'hreflang', 'hspace', 'id', 'ismap', 'label', 'lang', | |
| 160 'longdesc', 'maxlength', 'media', 'method', 'multiple', 'name', | |
| 161 'nohref', 'noshade', 'nowrap', 'prompt', 'readonly', 'rel', 'rev', | |
| 162 'rows', 'rowspan', 'rules', 'scope', 'selected', 'shape', 'size', | |
| 163 'span', 'src', 'start', 'style', 'summary', 'tabindex', 'target', | |
| 164 'title', 'type', 'usemap', 'valign', 'value', 'vspace', 'width']) | |
| 165 _URI_ATTRS = frozenset(['action', 'background', 'dynsrc', 'href', 'lowsrc', | |
| 166 'src']) | |
| 167 _SAFE_SCHEMES = frozenset(['file', 'ftp', 'http', 'https', 'mailto', None]) | |
| 168 | |
| 169 def __call__(self, stream, ctxt=None): | |
| 170 waiting_for = None | |
| 171 | |
| 172 for kind, data, pos in stream: | |
| 69 | 173 if kind is START: |
| 1 | 174 if waiting_for: |
| 175 continue | |
| 176 tag, attrib = data | |
| 177 if tag not in self._SAFE_TAGS: | |
| 178 waiting_for = tag | |
| 179 continue | |
| 180 | |
| 181 new_attrib = [] | |
| 182 for attr, value in attrib: | |
| 183 if attr not in self._SAFE_ATTRS: | |
| 184 continue | |
| 185 elif attr in self._URI_ATTRS: | |
| 186 # Don't allow URI schemes such as "javascript:" | |
| 187 if self._get_scheme(value) not in self._SAFE_SCHEMES: | |
| 188 continue | |
| 189 elif attr == 'style': | |
| 190 # Remove dangerous CSS declarations from inline styles | |
| 191 decls = [] | |
| 192 for decl in filter(None, value.split(';')): | |
| 193 is_evil = False | |
| 194 if 'expression' in decl: | |
| 195 is_evil = True | |
| 196 for m in re.finditer(r'url\s*\(([^)]+)', decl): | |
| 197 if self._get_scheme(m.group(1)) not in self._SAFE_SCHEMES: | |
| 198 is_evil = True | |
| 199 break | |
| 200 if not is_evil: | |
| 201 decls.append(decl.strip()) | |
| 202 if not decls: | |
| 203 continue | |
| 204 value = '; '.join(decls) | |
| 205 new_attrib.append((attr, value)) | |
| 206 | |
| 207 yield kind, (tag, new_attrib), pos | |
| 208 | |
| 69 | 209 elif kind is END: |
| 1 | 210 tag = data |
| 211 if waiting_for: | |
| 212 if waiting_for == tag: | |
| 213 waiting_for = None | |
| 214 else: | |
| 215 yield kind, data, pos | |
| 216 | |
| 217 else: | |
| 218 if not waiting_for: | |
| 219 yield kind, data, pos | |
| 220 | |
| 221 def _get_scheme(self, text): | |
| 222 if ':' not in text: | |
| 223 return None | |
| 224 chars = [char for char in text.split(':', 1)[0] if char.isalnum()] | |
| 225 return ''.join(chars).lower() |