Doc/lib/xmlsaxutils.tex

   1 \section{\module{xml.sax.saxutils} ---
   2          SAX Utilities}
   3
   4 \declaremodule{standard}{xml.sax.saxutils}
   5 \modulesynopsis{Convenience functions and classes for use with SAX.}
   6 \sectionauthor{Martin v. L\"owis}{martin@v.loewis.de}
   7 \moduleauthor{Lars Marius Garshol}{larsga@garshol.priv.no}
   8
   9 \versionadded{2.0}
  10
  11
  12 The module \module{xml.sax.saxutils} contains a number of classes and
  13 functions that are commonly useful when creating SAX applications,
  14 either in direct use, or as base classes.
  15
  16 \begin{funcdesc}{escape}{data\optional{, entities}}
  17   Escape \character{\&}, \character{<}, and \character{>} in a string
  18   of data.
  19
  20   You can escape other strings of data by passing a dictionary as the
  21   optional \var{entities} parameter.  The keys and values must all be
  22   strings; each key will be replaced with its corresponding value.
  23 \end{funcdesc}
  24
  25 \begin{funcdesc}{unescape}{data\optional{, entities}}
  26   Unescape \character{\&amp;}, \character{\&lt;}, and \character{\&gt;}
  27   in a string of data.
  28
  29   You can unescape other strings of data by passing a dictionary as the
  30   optional \var{entities} parameter.  The keys and values must all be
  31   strings; each key will be replaced with its corresponding value.
  32
  33   \versionadded{2.3}
  34 \end{funcdesc}
  35
  36 \begin{funcdesc}{quoteattr}{data\optional{, entities}}
  37   Similar to \function{escape()}, but also prepares \var{data} to be
  38   used as an attribute value.  The return value is a quoted version of
  39   \var{data} with any additional required replacements.
  40   \function{quoteattr()} will select a quote character based on the
  41   content of \var{data}, attempting to avoid encoding any quote
  42   characters in the string.  If both single- and double-quote
  43   characters are already in \var{data}, the double-quote characters
  44   will be encoded and \var{data} will be wrapped in double-quotes.  The
  45   resulting string can be used directly as an attribute value:
  46
  47 \begin{verbatim}
  48 >>> print "<element attr=%s>" % quoteattr("ab ' cd \" ef")
  49 <element attr="ab ' cd &quot; ef">
  50 \end{verbatim}
  51
  52   This function is useful when generating attribute values for HTML or
  53   any SGML using the reference concrete syntax.
  54   \versionadded{2.2}
  55 \end{funcdesc}
  56
  57 \begin{classdesc}{XMLGenerator}{\optional{out\optional{, encoding}}}
  58   This class implements the \class{ContentHandler} interface by
  59   writing SAX events back into an XML document. In other words, using
  60   an \class{XMLGenerator} as the content handler will reproduce the
  61   original document being parsed. \var{out} should be a file-like
  62   object which will default to \var{sys.stdout}. \var{encoding} is the
  63   encoding of the output stream which defaults to \code{'iso-8859-1'}.
  64 \end{classdesc}
  65
  66 \begin{classdesc}{XMLFilterBase}{base}
  67   This class is designed to sit between an \class{XMLReader} and the
  68   client application's event handlers.  By default, it does nothing
  69   but pass requests up to the reader and events on to the handlers
  70   unmodified, but subclasses can override specific methods to modify
  71   the event stream or the configuration requests as they pass through.
  72 \end{classdesc}
  73
  74 \begin{funcdesc}{prepare_input_source}{source\optional{, base}}
  75   This function takes an input source and an optional base URL and
  76   returns a fully resolved \class{InputSource} object ready for
  77   reading.  The input source can be given as a string, a file-like
  78   object, or an \class{InputSource} object; parsers will use this
  79   function to implement the polymorphic \var{source} argument to their
  80   \method{parse()} method.
  81 \end{funcdesc}