| """\ |
| A library of useful helper classes to the SAX classes, for the |
| convenience of application and driver writers. |
| """ |
| |
| import os, urllib.parse, urllib.request |
| from . import handler |
| from . import xmlreader |
| |
| # See whether the xmlcharrefreplace error handler is |
| # supported |
| try: |
| from codecs import xmlcharrefreplace_errors |
| _error_handling = "xmlcharrefreplace" |
| del xmlcharrefreplace_errors |
| except ImportError: |
| _error_handling = "strict" |
| |
| def __dict_replace(s, d): |
| """Replace substrings of a string using a dictionary.""" |
| for key, value in d.items(): |
| s = s.replace(key, value) |
| return s |
| |
| def escape(data, entities={}): |
| """Escape &, <, and > in a string of data. |
| |
| You can escape other strings of data by passing a dictionary as |
| the optional entities parameter. The keys and values must all be |
| strings; each key will be replaced with its corresponding value. |
| """ |
| |
| # must do ampersand first |
| data = data.replace("&", "&") |
| data = data.replace(">", ">") |
| data = data.replace("<", "<") |
| if entities: |
| data = __dict_replace(data, entities) |
| return data |
| |
| def unescape(data, entities={}): |
| """Unescape &, <, and > in a string of data. |
| |
| You can unescape other strings of data by passing a dictionary as |
| the optional entities parameter. The keys and values must all be |
| strings; each key will be replaced with its corresponding value. |
| """ |
| data = data.replace("<", "<") |
| data = data.replace(">", ">") |
| if entities: |
| data = __dict_replace(data, entities) |
| # must do ampersand last |
| return data.replace("&", "&") |
| |
| def quoteattr(data, entities={}): |
| """Escape and quote an attribute value. |
| |
| Escape &, <, and > in a string of data, then quote it for use as |
| an attribute value. The \" character will be escaped as well, if |
| necessary. |
| |
| You can escape other strings of data by passing a dictionary as |
| the optional entities parameter. The keys and values must all be |
| strings; each key will be replaced with its corresponding value. |
| """ |
| entities = entities.copy() |
| entities.update({'\n': ' ', '\r': ' ', '\t':'	'}) |
| data = escape(data, entities) |
| if '"' in data: |
| if "'" in data: |
| data = '"%s"' % data.replace('"', """) |
| else: |
| data = "'%s'" % data |
| else: |
| data = '"%s"' % data |
| return data |
| |
| |
| class XMLGenerator(handler.ContentHandler): |
| |
| def __init__(self, out=None, encoding="iso-8859-1", short_empty_elements=False): |
| if out is None: |
| import sys |
| out = sys.stdout |
| handler.ContentHandler.__init__(self) |
| self._out = out |
| self._ns_contexts = [{}] # contains uri -> prefix dicts |
| self._current_context = self._ns_contexts[-1] |
| self._undeclared_ns_maps = [] |
| self._encoding = encoding |
| self._short_empty_elements = short_empty_elements |
| self._pending_start_element = False |
| |
| def _write(self, text): |
| if isinstance(text, str): |
| self._out.write(text) |
| else: |
| self._out.write(text.encode(self._encoding, _error_handling)) |
| |
| def _qname(self, name): |
| """Builds a qualified name from a (ns_url, localname) pair""" |
| if name[0]: |
| # Per http://www.w3.org/XML/1998/namespace, The 'xml' prefix is |
| # bound by definition to http://www.w3.org/XML/1998/namespace. It |
| # does not need to be declared and will not usually be found in |
| # self._current_context. |
| if 'http://www.w3.org/XML/1998/namespace' == name[0]: |
| return 'xml:' + name[1] |
| # The name is in a non-empty namespace |
| prefix = self._current_context[name[0]] |
| if prefix: |
| # If it is not the default namespace, prepend the prefix |
| return prefix + ":" + name[1] |
| # Return the unqualified name |
| return name[1] |
| |
| def _finish_pending_start_element(self,endElement=False): |
| if self._pending_start_element: |
| self._write('>') |
| self._pending_start_element = False |
| |
| # ContentHandler methods |
| |
| def startDocument(self): |
| self._write('<?xml version="1.0" encoding="%s"?>\n' % |
| self._encoding) |
| |
| def startPrefixMapping(self, prefix, uri): |
| self._ns_contexts.append(self._current_context.copy()) |
| self._current_context[uri] = prefix |
| self._undeclared_ns_maps.append((prefix, uri)) |
| |
| def endPrefixMapping(self, prefix): |
| self._current_context = self._ns_contexts[-1] |
| del self._ns_contexts[-1] |
| |
| def startElement(self, name, attrs): |
| self._finish_pending_start_element() |
| self._write('<' + name) |
| for (name, value) in attrs.items(): |
| self._write(' %s=%s' % (name, quoteattr(value))) |
| if self._short_empty_elements: |
| self._pending_start_element = True |
| else: |
| self._write(">") |
| |
| def endElement(self, name): |
| if self._pending_start_element: |
| self._write('/>') |
| self._pending_start_element = False |
| else: |
| self._write('</%s>' % name) |
| |
| def startElementNS(self, name, qname, attrs): |
| self._finish_pending_start_element() |
| self._write('<' + self._qname(name)) |
| |
| for prefix, uri in self._undeclared_ns_maps: |
| if prefix: |
| self._out.write(' xmlns:%s="%s"' % (prefix, uri)) |
| else: |
| self._out.write(' xmlns="%s"' % uri) |
| self._undeclared_ns_maps = [] |
| |
| for (name, value) in attrs.items(): |
| self._write(' %s=%s' % (self._qname(name), quoteattr(value))) |
| if self._short_empty_elements: |
| self._pending_start_element = True |
| else: |
| self._write(">") |
| |
| def endElementNS(self, name, qname): |
| if self._pending_start_element: |
| self._write('/>') |
| self._pending_start_element = False |
| else: |
| self._write('</%s>' % self._qname(name)) |
| |
| def characters(self, content): |
| if content: |
| self._finish_pending_start_element() |
| self._write(escape(content)) |
| |
| def ignorableWhitespace(self, content): |
| if content: |
| self._finish_pending_start_element() |
| self._write(content) |
| |
| def processingInstruction(self, target, data): |
| self._finish_pending_start_element() |
| self._write('<?%s %s?>' % (target, data)) |
| |
| |
| class XMLFilterBase(xmlreader.XMLReader): |
| """This class is designed to sit between an XMLReader and the |
| client application's event handlers. By default, it does nothing |
| but pass requests up to the reader and events on to the handlers |
| unmodified, but subclasses can override specific methods to modify |
| the event stream or the configuration requests as they pass |
| through.""" |
| |
| def __init__(self, parent = None): |
| xmlreader.XMLReader.__init__(self) |
| self._parent = parent |
| |
| # ErrorHandler methods |
| |
| def error(self, exception): |
| self._err_handler.error(exception) |
| |
| def fatalError(self, exception): |
| self._err_handler.fatalError(exception) |
| |
| def warning(self, exception): |
| self._err_handler.warning(exception) |
| |
| # ContentHandler methods |
| |
| def setDocumentLocator(self, locator): |
| self._cont_handler.setDocumentLocator(locator) |
| |
| def startDocument(self): |
| self._cont_handler.startDocument() |
| |
| def endDocument(self): |
| self._cont_handler.endDocument() |
| |
| def startPrefixMapping(self, prefix, uri): |
| self._cont_handler.startPrefixMapping(prefix, uri) |
| |
| def endPrefixMapping(self, prefix): |
| self._cont_handler.endPrefixMapping(prefix) |
| |
| def startElement(self, name, attrs): |
| self._cont_handler.startElement(name, attrs) |
| |
| def endElement(self, name): |
| self._cont_handler.endElement(name) |
| |
| def startElementNS(self, name, qname, attrs): |
| self._cont_handler.startElementNS(name, qname, attrs) |
| |
| def endElementNS(self, name, qname): |
| self._cont_handler.endElementNS(name, qname) |
| |
| def characters(self, content): |
| self._cont_handler.characters(content) |
| |
| def ignorableWhitespace(self, chars): |
| self._cont_handler.ignorableWhitespace(chars) |
| |
| def processingInstruction(self, target, data): |
| self._cont_handler.processingInstruction(target, data) |
| |
| def skippedEntity(self, name): |
| self._cont_handler.skippedEntity(name) |
| |
| # DTDHandler methods |
| |
| def notationDecl(self, name, publicId, systemId): |
| self._dtd_handler.notationDecl(name, publicId, systemId) |
| |
| def unparsedEntityDecl(self, name, publicId, systemId, ndata): |
| self._dtd_handler.unparsedEntityDecl(name, publicId, systemId, ndata) |
| |
| # EntityResolver methods |
| |
| def resolveEntity(self, publicId, systemId): |
| return self._ent_handler.resolveEntity(publicId, systemId) |
| |
| # XMLReader methods |
| |
| def parse(self, source): |
| self._parent.setContentHandler(self) |
| self._parent.setErrorHandler(self) |
| self._parent.setEntityResolver(self) |
| self._parent.setDTDHandler(self) |
| self._parent.parse(source) |
| |
| def setLocale(self, locale): |
| self._parent.setLocale(locale) |
| |
| def getFeature(self, name): |
| return self._parent.getFeature(name) |
| |
| def setFeature(self, name, state): |
| self._parent.setFeature(name, state) |
| |
| def getProperty(self, name): |
| return self._parent.getProperty(name) |
| |
| def setProperty(self, name, value): |
| self._parent.setProperty(name, value) |
| |
| # XMLFilter methods |
| |
| def getParent(self): |
| return self._parent |
| |
| def setParent(self, parent): |
| self._parent = parent |
| |
| # --- Utility functions |
| |
| def prepare_input_source(source, base=""): |
| """This function takes an InputSource and an optional base URL and |
| returns a fully resolved InputSource object ready for reading.""" |
| |
| if isinstance(source, str): |
| source = xmlreader.InputSource(source) |
| elif hasattr(source, "read"): |
| f = source |
| source = xmlreader.InputSource() |
| source.setByteStream(f) |
| if hasattr(f, "name"): |
| source.setSystemId(f.name) |
| |
| if source.getByteStream() is None: |
| sysid = source.getSystemId() |
| basehead = os.path.dirname(os.path.normpath(base)) |
| sysidfilename = os.path.join(basehead, sysid) |
| if os.path.isfile(sysidfilename): |
| source.setSystemId(sysidfilename) |
| f = open(sysidfilename, "rb") |
| else: |
| source.setSystemId(urllib.parse.urljoin(base, sysid)) |
| f = urllib.request.urlopen(source.getSystemId()) |
| |
| source.setByteStream(f) |
| |
| return source |