Lib/xml/sax/saxutils.py

   1 """
   2 A library of useful helper classes to the sax classes, for the
   3 convenience of application and driver writers.
   4
   5 $Id$
   6 """
   7
   8 import types, string, sys
   9 import handler
  10
  11 def escape(data, entities = {}):
  12     """Escape &, <, and > in a string of data.
  13     You can escape other strings of data by passing a dictionary as
  14     the optional entities parameter.  The keys and values must all be
  15     strings; each key will be replaced with its corresponding value.
  16     """
  17     data = string.replace(data, "&", "&amp;")
  18     data = string.replace(data, "<", "&lt;")
  19     data = string.replace(data, ">", "&gt;")
  20     for chars, entity in entities.items():
  21         data = string.replace(data, chars, entity)
  22     return data
  23
  24 class XMLGenerator(handler.ContentHandler):
  25
  26     def __init__(self, out = sys.stdout):
  27         handler.ContentHandler.__init__(self)
  28         self._out = out
  29
  30     # ContentHandler methods
  31
  32     def startDocument(self):
  33         self._out.write('<?xml version="1.0" encoding="iso-8859-1"?>\n')
  34
  35     def startPrefixMapping(self, prefix, uri):
  36         pass
  37
  38     def endPrefixMapping(self, prefix):
  39         pass
  40
  41     def startElement(self, name, attrs):
  42         if type(name)==type(()):
  43             uri, localname, prefix=name
  44             name="%s:%s"%(prefix,localname)
  45         self._out.write('<' + name)
  46         for (name, value) in attrs.items():
  47             self._out.write(' %s="%s"' % (name, escape(value)))
  48         self._out.write('>')
  49
  50     def endElement(self, name):
  51         # FIXME: not namespace friendly yet
  52         self._out.write('</%s>' % name)
  53
  54     def characters(self, content):
  55         self._out.write(escape(content))
  56
  57     def ignorableWhitespace(self, content):
  58         self._out.write(content)
  59
  60     def processingInstruction(self, target, data):
  61         self._out.write('<?%s %s?>' % (target, data))
  62
  63 class XMLFilterBase:
  64     """This class is designed to sit between an XMLReader and the
  65     client application's event handlers.  By default, it does nothing
  66     but pass requests up to the reader and events on to the handlers
  67     unmodified, but subclasses can override specific methods to modify
  68     the event stream or the configuration requests as they pass
  69     through."""
  70
  71     # ErrorHandler methods
  72
  73     def error(self, exception):
  74         self._err_handler.error(exception)
  75
  76     def fatalError(self, exception):
  77         self._err_handler.fatalError(exception)
  78
  79     def warning(self, exception):
  80         self._err_handler.warning(exception)
  81
  82     # ContentHandler methods
  83
  84     def setDocumentLocator(self, locator):
  85         self._cont_handler.setDocumentLocator(locator)
  86
  87     def startDocument(self):
  88         self._cont_handler.startDocument()
  89
  90     def endDocument(self):
  91         self._cont_handler.endDocument()
  92
  93     def startPrefixMapping(self, prefix, uri):
  94         self._cont_handler.startPrefixMapping(prefix, uri)
  95
  96     def endPrefixMapping(self, prefix):
  97         self._cont_handler.endPrefixMapping(prefix)
  98
  99     def startElement(self, name, attrs):
 100         self._cont_handler.startElement(name, attrs)
 101
 102     def endElement(self, name, qname):
 103         self._cont_handler.endElement(name, qname)
 104
 105     def characters(self, content):
 106         self._cont_handler.characters(content)
 107
 108     def ignorableWhitespace(self, chars, start, end):
 109         self._cont_handler.ignorableWhitespace(chars, start, end)
 110
 111     def processingInstruction(self, target, data):
 112         self._cont_handler.processingInstruction(target, data)
 113
 114     def skippedEntity(self, name):
 115         self._cont_handler.skippedEntity(name)
 116
 117     # DTDHandler methods
 118
 119     def notationDecl(self, name, publicId, systemId):
 120         self._dtd_handler.notationDecl(name, publicId, systemId)
 121
 122     def unparsedEntityDecl(self, name, publicId, systemId, ndata):
 123         self._dtd_handler.unparsedEntityDecl(name, publicId, systemId, ndata)
 124
 125     # EntityResolver methods
 126
 127     def resolveEntity(self, publicId, systemId):
 128         self._ent_handler.resolveEntity(publicId, systemId)
 129
 130     # XMLReader methods
 131
 132     def parse(self, source):
 133         self._parent.setContentHandler(self)
 134         self._parent.setErrorHandler(self)
 135         self._parent.setEntityResolver(self)
 136         self._parent.setDTDHandler(self)
 137         self._parent.parse(source)
 138
 139     def setLocale(self, locale):
 140         self._parent.setLocale(locale)
 141
 142     def getFeature(self, name):
 143         return self._parent.getFeature(name)
 144
 145     def setFeature(self, name, state):
 146         self._parent.setFeature(name, state)
 147
 148     def getProperty(self, name):
 149         return self._parent.getProperty(name)
 150
 151     def setProperty(self, name, value):
 152         self._parent.setProperty(name, value)
 153