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author | Fred Drake <fdrake@acm.org> | 2000-10-12 20:05:09 (GMT) |
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committer | Fred Drake <fdrake@acm.org> | 2000-10-12 20:05:09 (GMT) |
commit | 014f0e33946c212e60604b4cf819cfec9fabb041 (patch) | |
tree | 515bc8be5ed1ecfa28d94e0d6036601eab1ecaca /Doc/lib/xmlsaxreader.tex | |
parent | 110941a4ba037a3cab0224370aed71c465a2f865 (diff) | |
download | cpython-014f0e33946c212e60604b4cf819cfec9fabb041.zip cpython-014f0e33946c212e60604b4cf819cfec9fabb041.tar.gz cpython-014f0e33946c212e60604b4cf819cfec9fabb041.tar.bz2 |
Massive addition of SAX documentation from Martin von Loewis
<loewis@informatik.hu-berlin.de>.
Reorganized to be more like other parts of the documentation in its
arrangement, but with few content changes.
This closes SourceForge patch #101850.
Diffstat (limited to 'Doc/lib/xmlsaxreader.tex')
-rw-r--r-- | Doc/lib/xmlsaxreader.tex | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/Doc/lib/xmlsaxreader.tex b/Doc/lib/xmlsaxreader.tex new file mode 100644 index 0000000..1970c24 --- /dev/null +++ b/Doc/lib/xmlsaxreader.tex @@ -0,0 +1,337 @@ +\section{\module{xml.sax.xmlreader} --- + Interface for XML parsers} + +\declaremodule{standard}{xml.sax.xmlreader} +\modulesynopsis{Interface which SAX-compliant XML parsers must implement.} +\sectionauthor{Martin v. L\"owis}{loewis@informatik.hu-berlin.de} +\moduleauthor{Lars Marius Garshol}{larsga@garshol.priv.no} + +\versionadded{2.0} + + +SAX parsers implement the \class{XMLReader} interface. They are +implemented in a Python module, which must provide a function +\function{create_parser()}. This function is invoked by +\function{xml.sax.make_parser()} with no arguments to create a new +parser object. + +\begin{classdesc}{XMLReader}{} + Base class which can be inherited by SAX parsers. +\end{classdesc} + +\begin{classdesc}{IncrementalParser}{} + In some cases, it is desirable not to parse an input source at once, + but to feed chunks of the document as they get available. Note that + the reader will normally not read the entire file, but read it in + chunks as well; still \method{parse()} won't return until the entire + document is processed. So these interfaces should be used if the + blocking behaviour of \method{parse()} is not desirable. + + When the parser is instantiated it is ready to begin accepting data + from the feed method immediately. After parsing has been finished + with a call to close the reset method must be called to make the + parser ready to accept new data, either from feed or using the parse + method. + + Note that these methods must \emph{not} be called during parsing, + that is, after parse has been called and before it returns. + + By default, the class also implements the parse method of the + XMLReader interface using the feed, close and reset methods of the + IncrementalParser interface as a convenience to SAX 2.0 driver + writers. +\end{classdesc} + +\begin{classdesc}{Locator}{} + Interface for associating a SAX event with a document location. A + locator object will return valid results only during calls to + DocumentHandler methods; at any other time, the results are + unpredictable. If information is not available, methods may return + \code{None}. +\end{classdesc} + +\begin{classdesc}{InputSource}{\optional{systemId}} + Encapsulation of the information needed by the \class{XMLReader} to + read entities. + + This class may include information about the public identifier, + system identifier, byte stream (possibly with character encoding + information) and/or the character stream of an entity. + + Applications will create objects of this class for use in the + \method{XMLReader.parse()} method and for returning from + EntityResolver.resolveEntity. + + An \class{InputSource} belongs to the application, the + \class{XMLReader} is not allowed to modify \class{InputSource} objects + passed to it from the application, although it may make copies and + modify those. +\end{classdesc} + +\begin{classdesc}{AttributesImpl}{attrs} + This is a dictionary-like object which represents the element + attributes in a \method{startElement()} call. In addition to the + most useful dictionary operations, it supports a number of other + methods as described below. Objects of this class should be + instantiated by readers; \var{attrs} must be a dictionary-like + object. +\end{classdesc} + +\begin{classdesc}{AttributesNSImpl}{attrs, qnames} + Namespace-aware variant of attributes, which will be passed to + \method{startElementNS()}. It is derived from \class{AttributesImpl}, + but understands attribute names as two-tuples of \var{namespaceURI} + and \var{localname}. In addition, it provides a number of methods + expecting qualified names as they appear in the original document. +\end{classdesc} + + +\subsection{XMLReader Objects \label{xmlreader-objects}} + +The \class{XMLReader} interface supports the following methods: + +\begin{methoddesc}[XMLReader]{parse}{source} + Process an input source, producing SAX events. The \var{source} + object can be a system identifier (i.e. a string identifying the + input source -- typically a file name or an URL), a file-like + object, or an \class{InputSource} object. When \method{parse()} + returns, the input is completely processed, and the parser object + can be discarded or reset. As a limitation, the current implementation + only accepts byte streams; processing of character streams is for + further study. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{getContentHandler}{} + Return the current \class{ContentHandler}. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{setContentHandler}{handler} + Set the current \class{ContentHandler}. If no + \class{ContentHandler} is set, content events will be discarded. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{getDTDHandler}{} + Return the current \class{DTDHandler}. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{setDTDHandler}{handler} + Set the current \class{DTDHandler}. If no \class{DTDHandler} is + set, DTD events will be discarded. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{getEntityResolver}{} + Return the current \class{EntityResolver}. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{setEntityResolver}{handler} + Set the current \class{EntityResolver}. If no + \class{EntityResolver} is set, attempts to resolve an external + entity will result in opening the system identifier for the entity, + and fail if it is not available. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{getErrorHandler}{} + Return the current \class{ErrorHandler}. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{setErrorHandler}{handler} + Set the current error handler. If no \class{ErrorHandler} is set, + errors will be raised as exceptions, and warnings will be printed. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{setLocale}{locale} + Allow an application to set the locale for errors and warnings. + + SAX parsers are not required to provide localization for errors and + warnings; if they cannot support the requested locale, however, they + must throw a SAX exception. Applications may request a locale change + in the middle of a parse. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{getFeature}{featurename} + Return the current setting for feature \var{featurename}. If the + feature is not recognized, \exception{SAXNotRecognizedException} is + raised. The well-known featurenames are listed in the module + \module{xml.sax.handler}. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{setFeature}{featurename, value} + Set the \var{featurename} to \var{value}. If the feature is not + recognized, \exception{SAXNotRecognizedException} is raised. If the + feature or its setting is not supported by the parser, + \var{SAXNotSupportedException} is raised. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{getProperty}{propertyname} + Return the current setting for property \var{propertyname}. If the + property is not recognized, a \exception{SAXNotRecognizedException} + is raised. The well-known propertynames are listed in the module + \module{xml.sax.handler}. +\end{methoddesc} + +\begin{methoddesc}[XMLReader]{setProperty}{propertyname, value} + Set the \var{propertyname} to \var{value}. If the property is not + recognized, \exception{SAXNotRecognizedException} is raised. If the + property or its setting is not supported by the parser, + \var{SAXNotSupportedException} is raised. +\end{methoddesc} + + +\subsection{IncrementalParser Objects + \label{incremental-parser-objects}} + +Instances of \class{IncrementalParser} offer the following additional +methods: + +\begin{methoddesc}[IncrementalParser]{feed}{data} + Process a chunk of \var{data}. +\end{methoddesc} + +\begin{methoddesc}[IncrementalParser]{close}{} + Assume the end of the document. That will check well-formedness + conditions that can be checked only at the end, invoke handlers, and + may clean up resources allocated during parsing. +\end{methoddesc} + +\begin{methoddesc}[IncrementalParser]{reset}{} + This method is called after close has been called to reset the + parser so that it is ready to parse new documents. The results of + calling parse or feed after close without calling reset are + undefined.""" +\end{methoddesc} + + +\subsection{Locator Objects \label{locator-objects}} + +Instances of \class{Locator} provide these methods: + +\begin{methoddesc}[Locator]{getColumnNumber}{} + Return the column number where the current event ends. +\end{methoddesc} + +\begin{methoddesc}[Locator]{getLineNumber}{} + Return the line number where the current event ends. +\end{methoddesc} + +\begin{methoddesc}[Locator]{getPublicId}{} + Return the public identifier for the current event. +\end{methoddesc} + +\begin{methoddesc}[Locator]{getSystemId}{} + Return the system identifier for the current event. +\end{methoddesc} + + +\subsection{InputSource Objects \label{input-source-objects}} + +\begin{methoddesc}[InputSource]{setPublicId}{id} + Sets the public identifier of this \class{InputSource}. +\end{methoddesc} + +\begin{methoddesc}[InputSource]{getPublicId}{} + Returns the public identifier of this \class{InputSource}. +\end{methoddesc} + +\begin{methoddesc}[InputSource]{setSystemId}{id} + Sets the system identifier of this \class{InputSource}. +\end{methoddesc} + +\begin{methoddesc}[InputSource]{getSystemId}{} + Returns the system identifier of this \class{InputSource}. +\end{methoddesc} + +\begin{methoddesc}[InputSource]{setEncoding}{encoding} + Sets the character encoding of this \class{InputSource}. + + The encoding must be a string acceptable for an XML encoding + declaration (see section 4.3.3 of the XML recommendation). + + The encoding attribute of the \class{InputSource} is ignored if the + \class{InputSource} also contains a character stream. +\end{methoddesc} + +\begin{methoddesc}[InputSource]{getEncoding}{} + Get the character encoding of this InputSource. +\end{methoddesc} + +\begin{methoddesc}[InputSource]{setByteStream}{bytefile} + Set the byte stream (a Python file-like object which does not + perform byte-to-character conversion) for this input source. + + The SAX parser will ignore this if there is also a character stream + specified, but it will use a byte stream in preference to opening a + URI connection itself. + + If the application knows the character encoding of the byte stream, + it should set it with the setEncoding method. +\end{methoddesc} + +\begin{methoddesc}[InputSource]{getByteStream}{} + Get the byte stream for this input source. + + The getEncoding method will return the character encoding for this + byte stream, or None if unknown. +\end{methoddesc} + +\begin{methoddesc}[InputSource]{setCharacterStream}{charfile} + Set the character stream for this input source. (The stream must be + a Python 1.6 Unicode-wrapped file-like that performs conversion to + Unicode strings.) + + If there is a character stream specified, the SAX parser will ignore + any byte stream and will not attempt to open a URI connection to the + system identifier. +\end{methoddesc} + +\begin{methoddesc}[InputSource]{getCharacterStream}{} + Get the character stream for this input source. +\end{methoddesc} + + +\subsection{AttributesImpl Objects \label{attributes-impl-objects}} + +\class{AttributesImpl} objects implement a portion of the mapping +protocol, and the methods \method{copy()}, \method{get()}, +\method{has_key()}, \method{items()}, \method{keys()}, and +\method{values()}. The following methods are also provided: + +\begin{methoddesc}[AttributesImpl]{getLength}{} + Return the number of attributes. +\end{methoddesc} + +\begin{methoddesc}[AttributesImpl]{getNames}{} + Return the names of the attributes. +\end{methoddesc} + +\begin{methoddesc}[AttributesImpl]{getType}{name} + Returns the type of the attribute \var{name}, which is normally + \code{'CDATA'}. +\end{methoddesc} + +\begin{methoddesc}[AttributesImpl]{getValue}{name} + Return the value of attribute \var{name}. +\end{methoddesc} + +% getValueByQName, getNameByQName, getQNameByName, getQNames available +% here already, but documented only for derived class. + + +\subsection{AttributesNSImpl Objects \label{attributes-ns-impl-objects}} + +\begin{methoddesc}[AttributesNSImpl]{getValueByQName}{name} + Return the value for a qualified name. +\end{methoddesc} + +\begin{methoddesc}[AttributesNSImpl]{getNameByQName}{name} + Return the \code{(\var{namespace}, \var{localname})} pair for a + qualified \var{name}. +\end{methoddesc} + +\begin{methoddesc}[AttributesNSImpl]{getQNameByName}{name} + Return the qualified name for a \code{(\var{namespace}, + \var{localname})} pair. +\end{methoddesc} + +\begin{methoddesc}[AttributesNSImpl]{getQNames}{} + Return the qualified names of all attributes. +\end{methoddesc} |