| 1 | """\ |
| 2 | A library of useful helper classes to the SAX classes, for the |
| 3 | convenience of application and driver writers. |
| 4 | """ |
| 5 | |
| 6 | import os, urlparse, urllib, types |
| 7 | import handler |
| 8 | import xmlreader |
| 9 | |
| 10 | try: |
| 11 | _StringTypes = [types.StringType, types.UnicodeType] |
| 12 | except AttributeError: |
| 13 | _StringTypes = [types.StringType] |
| 14 | |
| 15 | # See whether the xmlcharrefreplace error handler is |
| 16 | # supported |
| 17 | try: |
| 18 | from codecs import xmlcharrefreplace_errors |
| 19 | _error_handling = "xmlcharrefreplace" |
| 20 | del xmlcharrefreplace_errors |
| 21 | except ImportError: |
| 22 | _error_handling = "strict" |
| 23 | |
| 24 | def __dict_replace(s, d): |
| 25 | """Replace substrings of a string using a dictionary.""" |
| 26 | for key, value in d.items(): |
| 27 | s = s.replace(key, value) |
| 28 | return s |
| 29 | |
| 30 | def escape(data, entities={}): |
| 31 | """Escape &, <, and > in a string of data. |
| 32 | |
| 33 | You can escape other strings of data by passing a dictionary as |
| 34 | the optional entities parameter. The keys and values must all be |
| 35 | strings; each key will be replaced with its corresponding value. |
| 36 | """ |
| 37 | |
| 38 | # must do ampersand first |
| 39 | data = data.replace("&", "&") |
| 40 | data = data.replace(">", ">") |
| 41 | data = data.replace("<", "<") |
| 42 | if entities: |
| 43 | data = __dict_replace(data, entities) |
| 44 | return data |
| 45 | |
| 46 | def unescape(data, entities={}): |
| 47 | """Unescape &, <, and > in a string of data. |
| 48 | |
| 49 | You can unescape other strings of data by passing a dictionary as |
| 50 | the optional entities parameter. The keys and values must all be |
| 51 | strings; each key will be replaced with its corresponding value. |
| 52 | """ |
| 53 | data = data.replace("<", "<") |
| 54 | data = data.replace(">", ">") |
| 55 | if entities: |
| 56 | data = __dict_replace(data, entities) |
| 57 | # must do ampersand last |
| 58 | return data.replace("&", "&") |
| 59 | |
| 60 | def quoteattr(data, entities={}): |
| 61 | """Escape and quote an attribute value. |
| 62 | |
| 63 | Escape &, <, and > in a string of data, then quote it for use as |
| 64 | an attribute value. The \" character will be escaped as well, if |
| 65 | necessary. |
| 66 | |
| 67 | You can escape other strings of data by passing a dictionary as |
| 68 | the optional entities parameter. The keys and values must all be |
| 69 | strings; each key will be replaced with its corresponding value. |
| 70 | """ |
| 71 | data = escape(data, entities) |
| 72 | if '"' in data: |
| 73 | if "'" in data: |
| 74 | data = '"%s"' % data.replace('"', """) |
| 75 | else: |
| 76 | data = "'%s'" % data |
| 77 | else: |
| 78 | data = '"%s"' % data |
| 79 | return data |
| 80 | |
| 81 | |
| 82 | class XMLGenerator(handler.ContentHandler): |
| 83 | |
| 84 | def __init__(self, out=None, encoding="iso-8859-1"): |
| 85 | if out is None: |
| 86 | import sys |
| 87 | out = sys.stdout |
| 88 | handler.ContentHandler.__init__(self) |
| 89 | self._out = out |
| 90 | self._ns_contexts = [{}] # contains uri -> prefix dicts |
| 91 | self._current_context = self._ns_contexts[-1] |
| 92 | self._undeclared_ns_maps = [] |
| 93 | self._encoding = encoding |
| 94 | |
| 95 | def _write(self, text): |
| 96 | if isinstance(text, str): |
| 97 | self._out.write(text) |
| 98 | else: |
| 99 | self._out.write(text.encode(self._encoding, _error_handling)) |
| 100 | |
| 101 | # ContentHandler methods |
| 102 | |
| 103 | def startDocument(self): |
| 104 | self._write('<?xml version="1.0" encoding="%s"?>\n' % |
| 105 | self._encoding) |
| 106 | |
| 107 | def startPrefixMapping(self, prefix, uri): |
| 108 | self._ns_contexts.append(self._current_context.copy()) |
| 109 | self._current_context[uri] = prefix |
| 110 | self._undeclared_ns_maps.append((prefix, uri)) |
| 111 | |
| 112 | def endPrefixMapping(self, prefix): |
| 113 | self._current_context = self._ns_contexts[-1] |
| 114 | del self._ns_contexts[-1] |
| 115 | |
| 116 | def startElement(self, name, attrs): |
| 117 | self._write('<' + name) |
| 118 | for (name, value) in attrs.items(): |
| 119 | self._write(' %s=%s' % (name, quoteattr(value))) |
| 120 | self._write('>') |
| 121 | |
| 122 | def endElement(self, name): |
| 123 | self._write('</%s>' % name) |
| 124 | |
| 125 | def startElementNS(self, name, qname, attrs): |
| 126 | if name[0] is None: |
| 127 | # if the name was not namespace-scoped, use the unqualified part |
| 128 | name = name[1] |
| 129 | else: |
| 130 | # else try to restore the original prefix from the namespace |
| 131 | name = self._current_context[name[0]] + ":" + name[1] |
| 132 | self._write('<' + name) |
| 133 | |
| 134 | for pair in self._undeclared_ns_maps: |
| 135 | self._write(' xmlns:%s="%s"' % pair) |
| 136 | self._undeclared_ns_maps = [] |
| 137 | |
| 138 | for (name, value) in attrs.items(): |
| 139 | name = self._current_context[name[0]] + ":" + name[1] |
| 140 | self._write(' %s=%s' % (name, quoteattr(value))) |
| 141 | self._write('>') |
| 142 | |
| 143 | def endElementNS(self, name, qname): |
| 144 | if name[0] is None: |
| 145 | name = name[1] |
| 146 | else: |
| 147 | name = self._current_context[name[0]] + ":" + name[1] |
| 148 | self._write('</%s>' % name) |
| 149 | |
| 150 | def characters(self, content): |
| 151 | self._write(escape(content)) |
| 152 | |
| 153 | def ignorableWhitespace(self, content): |
| 154 | self._write(content) |
| 155 | |
| 156 | def processingInstruction(self, target, data): |
| 157 | self._write('<?%s %s?>' % (target, data)) |
| 158 | |
| 159 | |
| 160 | class XMLFilterBase(xmlreader.XMLReader): |
| 161 | """This class is designed to sit between an XMLReader and the |
| 162 | client application's event handlers. By default, it does nothing |
| 163 | but pass requests up to the reader and events on to the handlers |
| 164 | unmodified, but subclasses can override specific methods to modify |
| 165 | the event stream or the configuration requests as they pass |
| 166 | through.""" |
| 167 | |
| 168 | def __init__(self, parent = None): |
| 169 | xmlreader.XMLReader.__init__(self) |
| 170 | self._parent = parent |
| 171 | |
| 172 | # ErrorHandler methods |
| 173 | |
| 174 | def error(self, exception): |
| 175 | self._err_handler.error(exception) |
| 176 | |
| 177 | def fatalError(self, exception): |
| 178 | self._err_handler.fatalError(exception) |
| 179 | |
| 180 | def warning(self, exception): |
| 181 | self._err_handler.warning(exception) |
| 182 | |
| 183 | # ContentHandler methods |
| 184 | |
| 185 | def setDocumentLocator(self, locator): |
| 186 | self._cont_handler.setDocumentLocator(locator) |
| 187 | |
| 188 | def startDocument(self): |
| 189 | self._cont_handler.startDocument() |
| 190 | |
| 191 | def endDocument(self): |
| 192 | self._cont_handler.endDocument() |
| 193 | |
| 194 | def startPrefixMapping(self, prefix, uri): |
| 195 | self._cont_handler.startPrefixMapping(prefix, uri) |
| 196 | |
| 197 | def endPrefixMapping(self, prefix): |
| 198 | self._cont_handler.endPrefixMapping(prefix) |
| 199 | |
| 200 | def startElement(self, name, attrs): |
| 201 | self._cont_handler.startElement(name, attrs) |
| 202 | |
| 203 | def endElement(self, name): |
| 204 | self._cont_handler.endElement(name) |
| 205 | |
| 206 | def startElementNS(self, name, qname, attrs): |
| 207 | self._cont_handler.startElementNS(name, qname, attrs) |
| 208 | |
| 209 | def endElementNS(self, name, qname): |
| 210 | self._cont_handler.endElementNS(name, qname) |
| 211 | |
| 212 | def characters(self, content): |
| 213 | self._cont_handler.characters(content) |
| 214 | |
| 215 | def ignorableWhitespace(self, chars): |
| 216 | self._cont_handler.ignorableWhitespace(chars) |
| 217 | |
| 218 | def processingInstruction(self, target, data): |
| 219 | self._cont_handler.processingInstruction(target, data) |
| 220 | |
| 221 | def skippedEntity(self, name): |
| 222 | self._cont_handler.skippedEntity(name) |
| 223 | |
| 224 | # DTDHandler methods |
| 225 | |
| 226 | def notationDecl(self, name, publicId, systemId): |
| 227 | self._dtd_handler.notationDecl(name, publicId, systemId) |
| 228 | |
| 229 | def unparsedEntityDecl(self, name, publicId, systemId, ndata): |
| 230 | self._dtd_handler.unparsedEntityDecl(name, publicId, systemId, ndata) |
| 231 | |
| 232 | # EntityResolver methods |
| 233 | |
| 234 | def resolveEntity(self, publicId, systemId): |
| 235 | return self._ent_handler.resolveEntity(publicId, systemId) |
| 236 | |
| 237 | # XMLReader methods |
| 238 | |
| 239 | def parse(self, source): |
| 240 | self._parent.setContentHandler(self) |
| 241 | self._parent.setErrorHandler(self) |
| 242 | self._parent.setEntityResolver(self) |
| 243 | self._parent.setDTDHandler(self) |
| 244 | self._parent.parse(source) |
| 245 | |
| 246 | def setLocale(self, locale): |
| 247 | self._parent.setLocale(locale) |
| 248 | |
| 249 | def getFeature(self, name): |
| 250 | return self._parent.getFeature(name) |
| 251 | |
| 252 | def setFeature(self, name, state): |
| 253 | self._parent.setFeature(name, state) |
| 254 | |
| 255 | def getProperty(self, name): |
| 256 | return self._parent.getProperty(name) |
| 257 | |
| 258 | def setProperty(self, name, value): |
| 259 | self._parent.setProperty(name, value) |
| 260 | |
| 261 | # XMLFilter methods |
| 262 | |
| 263 | def getParent(self): |
| 264 | return self._parent |
| 265 | |
| 266 | def setParent(self, parent): |
| 267 | self._parent = parent |
| 268 | |
| 269 | # --- Utility functions |
| 270 | |
| 271 | def prepare_input_source(source, base = ""): |
| 272 | """This function takes an InputSource and an optional base URL and |
| 273 | returns a fully resolved InputSource object ready for reading.""" |
| 274 | |
| 275 | if type(source) in _StringTypes: |
| 276 | source = xmlreader.InputSource(source) |
| 277 | elif hasattr(source, "read"): |
| 278 | f = source |
| 279 | source = xmlreader.InputSource() |
| 280 | source.setByteStream(f) |
| 281 | if hasattr(f, "name"): |
| 282 | source.setSystemId(f.name) |
| 283 | |
| 284 | if source.getByteStream() is None: |
| 285 | sysid = source.getSystemId() |
| 286 | basehead = os.path.dirname(os.path.normpath(base)) |
| 287 | sysidfilename = os.path.join(basehead, sysid) |
| 288 | if os.path.isfile(sysidfilename): |
| 289 | source.setSystemId(sysidfilename) |
| 290 | f = open(sysidfilename, "rb") |
| 291 | else: |
| 292 | source.setSystemId(urlparse.urljoin(base, sysid)) |
| 293 | f = urllib.urlopen(source.getSystemId()) |
| 294 | |
| 295 | source.setByteStream(f) |
| 296 | |
| 297 | return source |