Doc/lib/xmlsax.tex

   1 \section{\module{xml.sax} ---
   2          Support for SAX2 parsers}
   3
   4 \declaremodule{standard}{xml.sax}
   5 \modulesynopsis{Package containing SAX2 base classes and convenience
   6                 functions.}
   7 \moduleauthor{Lars Marius Garshol}{larsga@garshol.priv.no}
   8 \sectionauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
   9
  10 \versionadded{2.0}
  11
  12
  13 The \module{xml.sax} package provides a number of modules which
  14 implement the Simple API for XML (SAX) interface for Python.  The
  15 package itself provides the SAX exceptions and the convenience
  16 functions which will be most used by users of the SAX API.
  17
  18 The convenience functions are:
  19
  20 \begin{funcdesc}{make_parser}{\optional{parser_list}}
  21   Create and return a SAX \class{XMLReader} object.  The first parser
  22   found will be used.  If \var{parser_list} is provided, it must be a
  23   sequence of strings which name modules that have a function named
  24   \function{create_parser()}.  Modules listed in \var{parser_list}
  25   will be used before modules in the default list of parsers.
  26 \end{funcdesc}
  27
  28 \begin{funcdesc}{parse}{filename_or_stream, handler\optional{, error_handler}}
  29   Create a SAX parser and use it to parse a document.  The document,
  30   passed in as \var{filename_or_stream}, can be a filename or a file
  31   object.  The \var{handler} parameter needs to be a SAX
  32   \class{ContentHandler} instance.  If \var{error_handler} is given,
  33   it must be a SAX \class{ErrorHandler} instance; if omitted,
  34   \exception{SAXParseException} will be raised on all errors.  There
  35   is no return value; all work must be done by the \var{handler}
  36   passed in.
  37 \end{funcdesc}
  38
  39 \begin{funcdesc}{parseString}{string, handler\optional{, error_handler}}
  40   Similar to \function{parse()}, but parses from a buffer \var{string}
  41   received as a parameter.
  42 \end{funcdesc}
  43
  44
  45 The SAX exceptions are also provided here:
  46
  47 \begin{excclassdesc}{SAXException}{msg\optional{, exception}}
  48   Encapsulate an XML error or warning.  This class can contain basic
  49   error or warning information from either the XML parser or the
  50   application: it can be subclassed to provide additional
  51   functionality or to add localization.  Note that although the
  52   handlers defined in the \class{ErrorHandler} interface receive
  53   instances of this exception, it is not required to actually raise
  54   the exception --- it is also useful as a container for information.
  55
  56   When instantiated, \var{msg} should be a human-readable description
  57   of the error.  The optional \var{exception} parameter, if given,
  58   should be \code{None} or an exception that was caught by the parsing
  59   code and is being passed along as information.
  60
  61   This is the base class for the other SAX exception classes.
  62 \end{excclassdesc}
  63
  64 \begin{excclassdesc}{SAXParseException}{msg, exception, locator}
  65   Subclass of \exception{SAXException} raised on parse errors.
  66   Instances of this class are passed to the methods of the SAX
  67   \class{ErrorHandler} interface to provide information about the
  68   parse error.  This class supports the SAX \class{Locator} interface
  69   as well as the \class{SAXException} interface.
  70 \end{excclassdesc}
  71
  72 \begin{excclassdesc}{SAXNotRecognizedException}{msg\optional{, exception}}
  73   Subclass of \exception{SAXException} raised when a SAX
  74   \class{XMLReader} is confronted with an unrecognized feature or
  75   property.  SAX applications and extensions may use this class for
  76   similar purposes.
  77 \end{excclassdesc}
  78
  79 \begin{excclassdesc}{SAXNotSupportedException}{msg\optional{, exception}}
  80   Subclass of \exception{SAXException} raised when a SAX
  81   \class{XMLReader} is asked to enable a feature that is not
  82   supported, or to set a property to a value that the implementation
  83   does not support.  SAX applications and extensions may use this
  84   class for similar purposes.
  85 \end{excclassdesc}
  86
  87
  88 \begin{seealso}
  89   \seetitle[http://www.megginson.com/SAX/]{SAX: The Simple API for
  90             XML}{This site is the focal point for the definition of
  91             the SAX API.  It provides a Java implementation and online
  92             documentation.  Links to implementations and historical
  93             information are also available.}
  94 \end{seealso}
  95
  96
  97 \subsection{SAXException Objects \label{saxexception-objects}}
  98
  99 The \class{SAXException} exception class supports the following
 100 methods:
 101
 102 \begin{methoddesc}[SAXException]{getMessage}{}
 103   Return a human-readable message describing the error condition.
 104 \end{methoddesc}
 105
 106 \begin{methoddesc}[SAXException]{getException}{}
 107   Return an encapsulated exception object, or \code{None}.
 108 \end{methoddesc}