Mercurial > genshi > mirror
annotate markup/core.py @ 5:dbb08edbc615 trunk
Improved `py:attrs` directive so that it removes existing attributes if they evaluate to `None` (AFAICT matching Kid behavior).
| author | cmlenz |
|---|---|
| date | Sat, 03 Jun 2006 15:29:27 +0000 |
| parents | 5479aae32f5a |
| children | 71e8e645fe81 |
| rev | line source |
|---|---|
| 1 | 1 # -*- coding: utf-8 -*- |
| 2 # | |
| 3 # Copyright (C) 2006 Christopher Lenz | |
| 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 | |
| 8 # are also available at http://trac.edgewall.com/license.html. | |
| 9 # | |
| 10 # This software consists of voluntary contributions made by many | |
| 11 # individuals. For the exact contribution history, see the revision | |
| 12 # history and logs, available at http://projects.edgewall.com/trac/. | |
| 13 | |
| 14 """Core classes for markup processing.""" | |
| 15 | |
| 16 import htmlentitydefs | |
| 17 import re | |
| 18 from StringIO import StringIO | |
| 19 | |
| 20 __all__ = ['Stream', 'Markup', 'escape', 'unescape', 'Namespace', 'QName'] | |
| 21 | |
| 22 | |
| 23 class StreamEventKind(object): | |
| 24 """A kind of event on an XML stream.""" | |
| 25 | |
| 26 __slots__ = ['name'] | |
| 27 | |
| 28 def __init__(self, name): | |
| 29 self.name = name | |
| 30 | |
| 31 def __repr__(self): | |
| 32 return self.name | |
| 33 | |
| 34 | |
| 35 class Stream(object): | |
| 36 """Represents a stream of markup events. | |
| 37 | |
| 38 This class is basically an iterator over the events. | |
| 39 | |
| 40 Also provided are ways to serialize the stream to text. The `serialize()` | |
| 41 method will return an iterator over generated strings, while `render()` | |
| 42 returns the complete generated text at once. Both accept various parameters | |
| 43 that impact the way the stream is serialized. | |
| 44 | |
| 45 Stream events are tuples of the form: | |
| 46 | |
| 47 (kind, data, position) | |
| 48 | |
| 49 where `kind` is the event kind (such as `START`, `END`, `TEXT`, etc), `data` | |
| 50 depends on the kind of event, and `position` is a `(line, offset)` tuple | |
| 51 that contains the location of the original element or text in the input. | |
| 52 """ | |
| 53 __slots__ = ['events'] | |
| 54 | |
| 55 START = StreamEventKind('start') # a start tag | |
| 56 END = StreamEventKind('end') # an end tag | |
| 57 TEXT = StreamEventKind('text') # literal text | |
| 58 EXPR = StreamEventKind('expr') # an expression | |
| 59 SUB = StreamEventKind('sub') # a "subprogram" | |
| 60 PROLOG = StreamEventKind('prolog') # XML prolog | |
| 61 DOCTYPE = StreamEventKind('doctype') # doctype declaration | |
| 62 START_NS = StreamEventKind('start-ns') # start namespace mapping | |
| 63 END_NS = StreamEventKind('end-ns') # end namespace mapping | |
| 64 PI = StreamEventKind('pi') # processing instruction | |
| 65 COMMENT = StreamEventKind('comment') # comment | |
| 66 | |
| 67 def __init__(self, events): | |
| 68 """Initialize the stream with a sequence of markup events. | |
| 69 | |
| 70 @oaram events: a sequence or iterable providing the events | |
| 71 """ | |
| 72 self.events = events | |
| 73 | |
| 74 def __iter__(self): | |
| 75 return iter(self.events) | |
| 76 | |
| 77 def render(self, method='xml', encoding='utf-8', **kwargs): | |
| 78 """Return a string representation of the stream. | |
| 79 | |
| 80 @param method: determines how the stream is serialized; can be either | |
| 81 'xml' or 'html', or a custom `Serializer` subclass | |
| 82 @param encoding: how the output string should be encoded; if set to | |
| 83 `None`, this method returns a `unicode` object | |
| 84 | |
| 85 Any additional keyword arguments are passed to the serializer, and thus | |
| 86 depend on the `method` parameter value. | |
| 87 """ | |
| 88 retval = u''.join(self.serialize(method=method, **kwargs)) | |
| 89 if encoding is not None: | |
| 90 return retval.encode('utf-8') | |
| 91 return retval | |
| 92 | |
| 93 def select(self, path): | |
| 94 """Return a new stream that contains the events matching the given | |
| 95 XPath expression. | |
| 96 | |
| 97 @param path: a string containing the XPath expression | |
| 98 """ | |
| 99 from markup.path import Path | |
| 100 path = Path(path) | |
| 101 return path.select(self) | |
| 102 | |
| 103 def serialize(self, method='xml', **kwargs): | |
| 104 """Generate strings corresponding to a specific serialization of the | |
| 105 stream. | |
| 106 | |
| 107 Unlike the `render()` method, this method is a generator this returns | |
| 108 the serialized output incrementally, as opposed to returning a single | |
| 109 string. | |
| 110 | |
| 111 @param method: determines how the stream is serialized; can be either | |
| 112 'xml' or 'html', or a custom `Serializer` subclass | |
| 113 """ | |
| 114 from markup import output | |
| 115 cls = method | |
| 116 if isinstance(method, basestring): | |
| 117 cls = {'xml': output.XMLSerializer, | |
| 118 'html': output.HTMLSerializer}[method] | |
| 119 else: | |
| 120 assert issubclass(cls, serializers.Serializer) | |
| 121 serializer = cls(**kwargs) | |
| 122 return serializer.serialize(self) | |
| 123 | |
| 124 def __str__(self): | |
| 125 return self.render() | |
| 126 | |
| 127 def __unicode__(self): | |
| 128 return self.render(encoding=None) | |
| 129 | |
| 130 | |
| 131 class Attributes(list): | |
| 132 | |
| 133 def __init__(self, attrib=None): | |
| 134 list.__init__(self, map(lambda (k, v): (QName(k), v), attrib or [])) | |
| 135 | |
| 136 def __contains__(self, name): | |
| 137 return name in [attr for attr, value in self] | |
| 138 | |
| 139 def get(self, name, default=None): | |
| 140 for attr, value in self: | |
| 141 if attr == name: | |
| 142 return value | |
| 143 return default | |
| 144 | |
|
5
dbb08edbc615
Improved `py:attrs` directive so that it removes existing attributes if they evaluate to `None` (AFAICT matching Kid behavior).
cmlenz
parents:
1
diff
changeset
|
145 def remove(self, name): |
|
dbb08edbc615
Improved `py:attrs` directive so that it removes existing attributes if they evaluate to `None` (AFAICT matching Kid behavior).
cmlenz
parents:
1
diff
changeset
|
146 for idx, (attr, _) in enumerate(self): |
|
dbb08edbc615
Improved `py:attrs` directive so that it removes existing attributes if they evaluate to `None` (AFAICT matching Kid behavior).
cmlenz
parents:
1
diff
changeset
|
147 if attr == name: |
|
dbb08edbc615
Improved `py:attrs` directive so that it removes existing attributes if they evaluate to `None` (AFAICT matching Kid behavior).
cmlenz
parents:
1
diff
changeset
|
148 del self[idx] |
|
dbb08edbc615
Improved `py:attrs` directive so that it removes existing attributes if they evaluate to `None` (AFAICT matching Kid behavior).
cmlenz
parents:
1
diff
changeset
|
149 break |
|
dbb08edbc615
Improved `py:attrs` directive so that it removes existing attributes if they evaluate to `None` (AFAICT matching Kid behavior).
cmlenz
parents:
1
diff
changeset
|
150 |
| 1 | 151 def set(self, name, value): |
| 152 for idx, (attr, _) in enumerate(self): | |
| 153 if attr == name: | |
| 154 self[idx] = (attr, value) | |
| 155 break | |
| 156 else: | |
| 157 self.append((QName(name), value)) | |
| 158 | |
| 159 | |
| 160 class Markup(unicode): | |
| 161 """Marks a string as being safe for inclusion in HTML/XML output without | |
| 162 needing to be escaped. | |
| 163 """ | |
| 164 def __new__(self, text='', *args): | |
| 165 if args: | |
| 166 text %= tuple([escape(arg) for arg in args]) | |
| 167 return unicode.__new__(self, text) | |
| 168 | |
| 169 def __add__(self, other): | |
| 170 return Markup(unicode(self) + Markup.escape(other)) | |
| 171 | |
| 172 def __mod__(self, args): | |
| 173 if not isinstance(args, (list, tuple)): | |
| 174 args = [args] | |
| 175 return Markup(unicode.__mod__(self, | |
| 176 tuple([escape(arg) for arg in args]))) | |
| 177 | |
| 178 def __mul__(self, num): | |
| 179 return Markup(unicode(self) * num) | |
| 180 | |
| 181 def join(self, seq): | |
| 182 return Markup(unicode(self).join([Markup.escape(item) for item in seq])) | |
| 183 | |
| 184 def stripentities(self, keepxmlentities=False): | |
| 185 """Return a copy of the text with any character or numeric entities | |
| 186 replaced by the equivalent UTF-8 characters. | |
| 187 | |
| 188 If the `keepxmlentities` parameter is provided and evaluates to `True`, | |
| 189 the core XML entities (&, ', >, < and "). | |
| 190 """ | |
| 191 def _replace_entity(match): | |
| 192 if match.group(1): # numeric entity | |
| 193 ref = match.group(1) | |
| 194 if ref.startswith('x'): | |
| 195 ref = int(ref[1:], 16) | |
| 196 else: | |
| 197 ref = int(ref, 10) | |
| 198 return unichr(ref) | |
| 199 else: # character entity | |
| 200 ref = match.group(2) | |
| 201 if keepxmlentities and ref in ('amp', 'apos', 'gt', 'lt', 'quot'): | |
| 202 return '&%s;' % ref | |
| 203 try: | |
| 204 codepoint = htmlentitydefs.name2codepoint[ref] | |
| 205 return unichr(codepoint) | |
| 206 except KeyError: | |
| 207 if keepxmlentities: | |
| 208 return '&%s;' % ref | |
| 209 else: | |
| 210 return ref | |
| 211 return Markup(re.sub(r'&(?:#((?:\d+)|(?:[xX][0-9a-fA-F]+));?|(\w+);)', | |
| 212 _replace_entity, self)) | |
| 213 | |
| 214 def striptags(self): | |
| 215 """Return a copy of the text with all XML/HTML tags removed.""" | |
| 216 return Markup(re.sub(r'<[^>]*?>', '', self)) | |
| 217 | |
| 218 def escape(cls, text, quotes=True): | |
| 219 """Create a Markup instance from a string and escape special characters | |
| 220 it may contain (<, >, & and \"). | |
| 221 | |
| 222 If the `quotes` parameter is set to `False`, the \" character is left | |
| 223 as is. Escaping quotes is generally only required for strings that are | |
| 224 to be used in attribute values. | |
| 225 """ | |
| 226 if isinstance(text, cls): | |
| 227 return text | |
| 228 text = unicode(text) | |
| 229 if not text: | |
| 230 return cls() | |
| 231 text = text.replace('&', '&') \ | |
| 232 .replace('<', '<') \ | |
| 233 .replace('>', '>') | |
| 234 if quotes: | |
| 235 text = text.replace('"', '"') | |
| 236 return cls(text) | |
| 237 escape = classmethod(escape) | |
| 238 | |
| 239 def unescape(self): | |
| 240 """Reverse-escapes &, <, > and \" and returns a `unicode` object.""" | |
| 241 if not self: | |
| 242 return '' | |
| 243 return unicode(self).replace('"', '"') \ | |
| 244 .replace('>', '>') \ | |
| 245 .replace('<', '<') \ | |
| 246 .replace('&', '&') | |
| 247 | |
| 248 def plaintext(self, keeplinebreaks=True): | |
| 249 """Returns the text as a `unicode`with all entities and tags removed.""" | |
| 250 text = unicode(self.striptags().stripentities()) | |
| 251 if not keeplinebreaks: | |
| 252 text = text.replace('\n', ' ') | |
| 253 return text | |
| 254 | |
| 255 def sanitize(self): | |
| 256 from markup.filters import HTMLSanitizer | |
| 257 from markup.input import HTMLParser | |
| 258 sanitize = HTMLSanitizer() | |
| 259 text = self.stripentities(keepxmlentities=True) | |
| 260 return Stream(sanitize(HTMLParser(StringIO(text)), None)) | |
| 261 | |
| 262 | |
| 263 escape = Markup.escape | |
| 264 | |
| 265 def unescape(text): | |
| 266 """Reverse-escapes &, <, > and \" and returns a `unicode` object.""" | |
| 267 if not isinstance(text, Markup): | |
| 268 return text | |
| 269 return text.unescape() | |
| 270 | |
| 271 | |
| 272 class Namespace(object): | |
| 273 | |
| 274 def __init__(self, uri): | |
| 275 self.uri = uri | |
| 276 | |
| 277 def __getitem__(self, name): | |
| 278 return QName(self.uri + '}' + name) | |
| 279 | |
| 280 __getattr__ = __getitem__ | |
| 281 | |
| 282 def __repr__(self): | |
| 283 return '<Namespace "%s">' % self.uri | |
| 284 | |
| 285 def __str__(self): | |
| 286 return self.uri | |
| 287 | |
| 288 def __unicode__(self): | |
| 289 return unicode(self.uri) | |
| 290 | |
| 291 | |
| 292 class QName(unicode): | |
| 293 """A qualified element or attribute name. | |
| 294 | |
| 295 The unicode value of instances of this class contains the qualified name of | |
| 296 the element or attribute, in the form `{namespace}localname`. The namespace | |
| 297 URI can be obtained through the additional `namespace` attribute, while the | |
| 298 local name can be accessed through the `localname` attribute. | |
| 299 """ | |
| 300 __slots__ = ['namespace', 'localname'] | |
| 301 | |
| 302 def __new__(cls, qname): | |
| 303 if isinstance(qname, QName): | |
| 304 return qname | |
| 305 | |
| 306 parts = qname.split('}', 1) | |
| 307 if qname.find('}') > 0: | |
| 308 self = unicode.__new__(cls, '{' + qname) | |
| 309 self.namespace = parts[0] | |
| 310 self.localname = parts[1] | |
| 311 else: | |
| 312 self = unicode.__new__(cls, qname) | |
| 313 self.namespace = None | |
| 314 self.localname = qname | |
| 315 return self |