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author | Guido van Rossum <guido@python.org> | 1997-11-18 15:11:22 (GMT) |
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committer | Guido van Rossum <guido@python.org> | 1997-11-18 15:11:22 (GMT) |
commit | a10768ae44d0547448e6a7940338342be41b1d76 (patch) | |
tree | ed15b02979597925396780aa3360e918bcf85624 /Doc/libxmllib.tex | |
parent | b62b6d145e098ca010d962de1f15ac970d3480f6 (diff) | |
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Docu for xmllib.py, by Sjoerd Mullender.
Diffstat (limited to 'Doc/libxmllib.tex')
-rw-r--r-- | Doc/libxmllib.tex | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/Doc/libxmllib.tex b/Doc/libxmllib.tex new file mode 100644 index 0000000..d75d121 --- /dev/null +++ b/Doc/libxmllib.tex @@ -0,0 +1,185 @@ +\section{Standard Module \sectcode{xmllib}} +% Author: Sjoerd Mullender +\label{module-xmllib} +\stmodindex{xmllib} +\index{XML} + +This module defines a class \code{XMLParser} which serves as the basis +for parsing text files formatted in XML (eXtended Markup Language). + +The \code{XMLParser} class must be instantiated without arguments. It +has the following interface methods: + +\renewcommand{\indexsubitem}{({\tt XMLParser} method)} + +\begin{funcdesc}{reset}{} +Reset the instance. Loses all unprocessed data. This is called +implicitly at the instantiation time. +\end{funcdesc} + +\begin{funcdesc}{setnomoretags}{} +Stop processing tags. Treat all following input as literal input +(CDATA). +\end{funcdesc} + +\begin{funcdesc}{setliteral}{} +Enter literal mode (CDATA mode). +\end{funcdesc} + +\begin{funcdesc}{feed}{data} +Feed some text to the parser. It is processed insofar as it consists +of complete elements; incomplete data is buffered until more data is +fed or \code{close()} is called. +\end{funcdesc} + +\begin{funcdesc}{close}{} +Force processing of all buffered data as if it were followed by an +end-of-file mark. This method may be redefined by a derived class to +define additional processing at the end of the input, but the +redefined version should always call \code{XMLParser.close()}. +\end{funcdesc} + +\begin{funcdesc}{handle_starttag}{tag\, method\, attributes} +This method is called to handle start tags for which a +\code{start_\var{tag}()} method has been defined. The \code{tag} +argument is the name of the tag, and the \code{method} argument is the +bound method which should be used to support semantic interpretation +of the start tag. The \var{attributes} argument is a dictionary of +attributes, the key being the \var{name} and the value being the +\var{value} of the attribute found inside the tag's \code{<>} brackets. +Lower case and double quotes and backslashes in the \var{value} have +been interpreted. For instance, for the tag +\code{<A HREF="http://www.cwi.nl/">}, this method would be called as +\code{handle_starttag('A', self.start_A, {'HREF': 'http://www.cwi.nl/'})}. +The base implementation simply calls \code{method} with \code{attributes} +as the only argument. +\end{funcdesc} + +\begin{funcdesc}{handle_endtag}{tag\, method} +This method is called to handle endtags for which an +\code{end_\var{tag}()} method has been defined. The \code{tag} +argument is the name of the tag, and the +\code{method} argument is the bound method which should be used to +support semantic interpretation of the end tag. If no +\code{end_\var{tag}()} method is defined for the closing element, this +handler is not called. The base implementation simply calls +\code{method}. +\end{funcdesc} + +\begin{funcdesc}{handle_data}{data} +This method is called to process arbitrary data. It is intended to be +overridden by a derived class; the base class implementation does +nothing. +\end{funcdesc} + +\begin{funcdesc}{handle_charref}{ref} +This method is called to process a character reference of the form +``\code{\&\#\var{ref};}''. \var{ref} can either be a decimal number, +or a hexadecimal number when preceded by \code{x}. +In the base implementation, \var{ref} must be a number in the +range 0-255. It translates the character to \ASCII{} and calls the +method \code{handle_data()} with the character as argument. If +\var{ref} is invalid or out of range, the method +\code{unknown_charref(\var{ref})} is called to handle the error. A +subclass must override this method to provide support for character +references outside of the \ASCII{} range. +\end{funcdesc} + +\begin{funcdesc}{handle_entityref}{ref} +This method is called to process a general entity reference of the form +``\code{\&\var{ref};}'' where \var{ref} is an general entity +reference. It looks for \var{ref} in the instance (or class) +variable \code{entitydefs} which should be a mapping from entity names +to corresponding translations. +If a translation is found, it calls the method \code{handle_data()} +with the translation; otherwise, it calls the method +\code{unknown_entityref(\var{ref})}. The default \code{entitydefs} +defines translations for \code{\&}, \code{\&apos}, \code{\>}, +\code{\<}, and \code{\"}. +\end{funcdesc} + +\begin{funcdesc}{handle_comment}{comment} +This method is called when a comment is encountered. The +\code{comment} argument is a string containing the text between the +``\code{<!--}'' and ``\code{-->}'' delimiters, but not the delimiters +themselves. For example, the comment ``\code{<!--text-->}'' will +cause this method to be called with the argument \code{'text'}. The +default method does nothing. +\end{funcdesc} + +\begin{funcdesc}{handle_cdata}{data} +This method is called when a CDATA element is encountered. The +\code{data} argument is a string containing the text between the +``\code{<![CDATA[}'' and ``\code{]]>}'' delimiters, but not the delimiters +themselves. For example, the entity ``\code{<![CDATA[text]]>}'' will +cause this method to be called with the argument \code{'text'}. The +default method does nothing. +\end{funcdesc} + +\begin{funcdesc}{handle_proc}{name\, data} +This method is called when a processing instruction (PI) is encountered. The +\code{name} is the PI target, and the \code{data} argument is a +string containing the text between the PI target and the closing delimiter, +but not the delimiter itself. For example, the instruction +``\code{<?XML text?>}'' will cause this method to be called with the +arguments \code{'XML'} and \code{'text'}. The default method does +nothing. +\end{funcdesc} + +\begin{funcdesc}{handle_special}{data} +This method is called when a declaration is encountered. The +\code{data} argument is a string containing the text between the +``\code{<!}'' and ``\code{>}'' delimiters, but not the delimiters +themselves. For example, the entity ``\code{<!DOCTYPE text>}'' will +cause this method to be called with the argument \code{'DOCTYPE text'}. The +default method does nothing. +\end{funcdesc} + +\begin{funcdesc}{syntax_error}{lineno\, message} +This method is called when a syntax error is encountered. The +\code{lineno} argument is the line number of the error, and the +\code{message} is a description of what was wrong. The default method +raises a \code{RuntimeError} exception. If this method is overridden, +it is permissable for it to return. This method is only called when +the error can be recovered from. +\end{funcdesc} + +\begin{funcdesc}{unknown_starttag}{tag\, attributes} +This method is called to process an unknown start tag. It is intended +to be overridden by a derived class; the base class implementation +does nothing. +\end{funcdesc} + +\begin{funcdesc}{unknown_endtag}{tag} +This method is called to process an unknown end tag. It is intended +to be overridden by a derived class; the base class implementation +does nothing. +\end{funcdesc} + +\begin{funcdesc}{unknown_charref}{ref} +This method is called to process unresolvable numeric character +references. It is intended to be overridden by a derived class; the +base class implementation does nothing. +\end{funcdesc} + +\begin{funcdesc}{unknown_entityref}{ref} +This method is called to process an unknown entity reference. It is +intended to be overridden by a derived class; the base class +implementation does nothing. +\end{funcdesc} + +Apart from overriding or extending the methods listed above, derived +classes may also define methods of the following form to define +processing of specific tags. Tag names in the input stream are case +dependent; the \var{tag} occurring in method names must be in the +correct case: + +\begin{funcdesc}{start_\var{tag}}{attributes} +This method is called to process an opening tag \var{tag}. The +\var{attributes} argument has the same meaning as described for +\code{handle_starttag()} above. +\end{funcdesc} + +\begin{funcdesc}{end_\var{tag}}{} +This method is called to process a closing tag \var{tag}. +\end{funcdesc} |