genshi/mirror: markup/core.py comparison

comparison markup/core.py @ 1:5479aae32f5a trunk

Initial import.

author	cmlenz
date	Sat, 03 Jun 2006 07:16:01 +0000
parents
children	dbb08edbc615

comparison

equal deleted inserted replaced

-:5f9862282a9d
+:5479aae32f5a
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2006 Christopher Lenz
+# All rights reserved.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at http://trac.edgewall.com/license.html.
+#
+# This software consists of voluntary contributions made by many
+# individuals. For the exact contribution history, see the revision
+# history and logs, available at http://projects.edgewall.com/trac/.
+"""Core classes for markup processing."""
+import htmlentitydefs
+import re
+from StringIO import StringIO
+__all__ = ['Stream', 'Markup', 'escape', 'unescape', 'Namespace', 'QName']
+class StreamEventKind(object):
+"""A kind of event on an XML stream."""
+__slots__ = ['name']
+def __init__(self, name):
+self.name = name
+def __repr__(self):
+return self.name
+class Stream(object):
+"""Represents a stream of markup events.
+This class is basically an iterator over the events.
+Also provided are ways to serialize the stream to text. The `serialize()`
+method will return an iterator over generated strings, while `render()`
+returns the complete generated text at once. Both accept various parameters
+that impact the way the stream is serialized.
+Stream events are tuples of the form:
+(kind, data, position)
+where `kind` is the event kind (such as `START`, `END`, `TEXT`, etc), `data`
+depends on the kind of event, and `position` is a `(line, offset)` tuple
+that contains the location of the original element or text in the input.
+"""
+__slots__ = ['events']
+START = StreamEventKind('start') # a start tag
+END = StreamEventKind('end') # an end tag
+TEXT = StreamEventKind('text') # literal text
+EXPR = StreamEventKind('expr') # an expression
+SUB = StreamEventKind('sub') # a "subprogram"
+PROLOG = StreamEventKind('prolog') # XML prolog
+DOCTYPE = StreamEventKind('doctype') # doctype declaration
+START_NS = StreamEventKind('start-ns') # start namespace mapping
+END_NS = StreamEventKind('end-ns') # end namespace mapping
+PI = StreamEventKind('pi') # processing instruction
+COMMENT = StreamEventKind('comment') # comment
+def __init__(self, events):
+"""Initialize the stream with a sequence of markup events.
+@oaram events: a sequence or iterable providing the events
+"""
+self.events = events
+def __iter__(self):
+return iter(self.events)
+def render(self, method='xml', encoding='utf-8', **kwargs):
+"""Return a string representation of the stream.
+@param method: determines how the stream is serialized; can be either
+'xml' or 'html', or a custom `Serializer` subclass
+@param encoding: how the output string should be encoded; if set to
+`None`, this method returns a `unicode` object
+Any additional keyword arguments are passed to the serializer, and thus
+depend on the `method` parameter value.
+"""
+retval = u''.join(self.serialize(method=method, **kwargs))
+if encoding is not None:
+return retval.encode('utf-8')
+return retval
+def select(self, path):
+"""Return a new stream that contains the events matching the given
+XPath expression.
+@param path: a string containing the XPath expression
+"""
+from markup.path import Path
+path = Path(path)
+return path.select(self)
+def serialize(self, method='xml', **kwargs):
+"""Generate strings corresponding to a specific serialization of the
+stream.
+Unlike the `render()` method, this method is a generator this returns
+the serialized output incrementally, as opposed to returning a single
+string.
+@param method: determines how the stream is serialized; can be either
+'xml' or 'html', or a custom `Serializer` subclass
+"""
+from markup import output
+cls = method
+if isinstance(method, basestring):
+cls = {'xml': output.XMLSerializer,
+'html': output.HTMLSerializer}[method]
+else:
+assert issubclass(cls, serializers.Serializer)
+serializer = cls(**kwargs)
+return serializer.serialize(self)
+def __str__(self):
+return self.render()
+def __unicode__(self):
+return self.render(encoding=None)
+class Attributes(list):
+def __init__(self, attrib=None):
+list.__init__(self, map(lambda (k, v): (QName(k), v), attrib or []))
+def __contains__(self, name):
+return name in [attr for attr, value in self]
+def get(self, name, default=None):
+for attr, value in self:
+if attr == name:
+return value
+return default
+def set(self, name, value):
+for idx, (attr, _) in enumerate(self):
+if attr == name:
+self[idx] = (attr, value)
+break
+else:
+self.append((QName(name), value))
+class Markup(unicode):
+"""Marks a string as being safe for inclusion in HTML/XML output without
+needing to be escaped.
+"""
+def __new__(self, text='', *args):
+if args:
+text %= tuple([escape(arg) for arg in args])
+return unicode.__new__(self, text)
+def __add__(self, other):
+return Markup(unicode(self) + Markup.escape(other))
+def __mod__(self, args):
+if not isinstance(args, (list, tuple)):
+args = [args]
+return Markup(unicode.__mod__(self,
+tuple([escape(arg) for arg in args])))
+def __mul__(self, num):
+return Markup(unicode(self) * num)
+def join(self, seq):
+return Markup(unicode(self).join([Markup.escape(item) for item in seq]))
+def stripentities(self, keepxmlentities=False):
+"""Return a copy of the text with any character or numeric entities
+replaced by the equivalent UTF-8 characters.
+If the `keepxmlentities` parameter is provided and evaluates to `True`,
+the core XML entities (&amp;, &apos;, &gt;, &lt; and &quot;).
+"""
+def _replace_entity(match):
+if match.group(1): # numeric entity
+ref = match.group(1)
+if ref.startswith('x'):
+ref = int(ref[1:], 16)
+else:
+ref = int(ref, 10)
+return unichr(ref)
+else: # character entity
+ref = match.group(2)
+if keepxmlentities and ref in ('amp', 'apos', 'gt', 'lt', 'quot'):
+return '&%s;' % ref
+try:
+codepoint = htmlentitydefs.name2codepoint[ref]
+return unichr(codepoint)
+except KeyError:
+if keepxmlentities:
+return '&amp;%s;' % ref
+else:
+return ref
+return Markup(re.sub(r'&(?:#((?:\d+)|(?:[xX][0-9a-fA-F]+));?|(\w+);)',
+_replace_entity, self))
+def striptags(self):
+"""Return a copy of the text with all XML/HTML tags removed."""
+return Markup(re.sub(r'<[^>]*?>', '', self))
+def escape(cls, text, quotes=True):
+"""Create a Markup instance from a string and escape special characters
+it may contain (<, >, & and \").
+If the `quotes` parameter is set to `False`, the \" character is left
+as is. Escaping quotes is generally only required for strings that are
+to be used in attribute values.
+"""
+if isinstance(text, cls):
+return text
+text = unicode(text)
+if not text:
+return cls()
+text = text.replace('&', '&amp;') \
+.replace('<', '&lt;') \
+.replace('>', '&gt;')
+if quotes:
+text = text.replace('"', '&#34;')
+return cls(text)
+escape = classmethod(escape)
+def unescape(self):
+"""Reverse-escapes &, <, > and \" and returns a `unicode` object."""
+if not self:
+return ''
+return unicode(self).replace('&#34;', '"') \
+.replace('&gt;', '>') \
+.replace('&lt;', '<') \
+.replace('&amp;', '&')
+def plaintext(self, keeplinebreaks=True):
+"""Returns the text as a `unicode`with all entities and tags removed."""
+text = unicode(self.striptags().stripentities())
+if not keeplinebreaks:
+text = text.replace('\n', ' ')
+return text
+def sanitize(self):
+from markup.filters import HTMLSanitizer
+from markup.input import HTMLParser
+sanitize = HTMLSanitizer()
+text = self.stripentities(keepxmlentities=True)
+return Stream(sanitize(HTMLParser(StringIO(text)), None))
+escape = Markup.escape
+def unescape(text):
+"""Reverse-escapes &, <, > and \" and returns a `unicode` object."""
+if not isinstance(text, Markup):
+return text
+return text.unescape()
+class Namespace(object):
+def __init__(self, uri):
+self.uri = uri
+def __getitem__(self, name):
+return QName(self.uri + '}' + name)
+__getattr__ = __getitem__
+def __repr__(self):
+return '<Namespace "%s">' % self.uri
+def __str__(self):
+return self.uri
+def __unicode__(self):
+return unicode(self.uri)
+class QName(unicode):
+"""A qualified element or attribute name.
+The unicode value of instances of this class contains the qualified name of
+the element or attribute, in the form `{namespace}localname`. The namespace
+URI can be obtained through the additional `namespace` attribute, while the
+local name can be accessed through the `localname` attribute.
+"""
+__slots__ = ['namespace', 'localname']
+def __new__(cls, qname):
+if isinstance(qname, QName):
+return qname
+parts = qname.split('}', 1)
+if qname.find('}') > 0:
+self = unicode.__new__(cls, '{' + qname)
+self.namespace = parts[0]
+self.localname = parts[1]
+else:
+self = unicode.__new__(cls, qname)
+self.namespace = None
+self.localname = qname
+return self

Mercurial > genshi > mirror

comparison markup/core.py @ 1:5479aae32f5a trunk