Lib/xml/sax/handler.py - platform/external/python/cpython3 - Gitiles

 """
 This module contains the core classes of version 2.0 of SAX for Python.
 This file provides only default classes with absolutely minimum
 functionality, from which drivers and applications can be subclassed.

 Many of these classes are empty and are included only as documentation
 of the interfaces.

 $Id$
 """

 version = '2.0beta'

 #============================================================================
 #
 # HANDLER INTERFACES
 #
 #============================================================================

 # ===== ERRORHANDLER =====

 class ErrorHandler:
     """Basic interface for SAX error handlers.

     If you create an object that implements this interface, then
     register the object with your XMLReader, the parser will call the
     methods in your object to report all warnings and errors. There
     are three levels of errors available: warnings, (possibly)
     recoverable errors, and unrecoverable errors. All methods take a
     SAXParseException as the only parameter."""

     def error(self, exception):
         "Handle a recoverable error."
         raise exception

     def fatalError(self, exception):
         "Handle a non-recoverable error."
         raise exception

     def warning(self, exception):
         "Handle a warning."
         print exception


 # ===== CONTENTHANDLER =====

 class ContentHandler:
     """Interface for receiving logical document content events.

     This is the main callback interface in SAX, and the one most
     important to applications. The order of events in this interface
     mirrors the order of the information in the document."""

     def __init__(self):
         self._locator = None

     def setDocumentLocator(self, locator):
         """Called by the parser to give the application a locator for
         locating the origin of document events.

         SAX parsers are strongly encouraged (though not absolutely
         required) to supply a locator: if it does so, it must supply
         the locator to the application by invoking this method before
         invoking any of the other methods in the DocumentHandler
         interface.

         The locator allows the application to determine the end
         position of any document-related event, even if the parser is
         not reporting an error. Typically, the application will use
         this information for reporting its own errors (such as
         character content that does not match an application's
         business rules). The information returned by the locator is
         probably not sufficient for use with a search engine.

         Note that the locator will return correct information only
         during the invocation of the events in this interface. The
         application should not attempt to use it at any other time."""
         self._locator = locator

     def startDocument(self):
         """Receive notification of the beginning of a document.

         The SAX parser will invoke this method only once, before any
         other methods in this interface or in DTDHandler (except for
         setDocumentLocator)."""

     def endDocument(self):
         """Receive notification of the end of a document.

         The SAX parser will invoke this method only once, and it will
         be the last method invoked during the parse. The parser shall
         not invoke this method until it has either abandoned parsing
         (because of an unrecoverable error) or reached the end of
         input."""

     def startPrefixMapping(self, prefix, uri):
         """Begin the scope of a prefix-URI Namespace mapping.

         The information from this event is not necessary for normal
         Namespace processing: the SAX XML reader will automatically
         replace prefixes for element and attribute names when the
         http://xml.org/sax/features/namespaces feature is true (the
         default).

         There are cases, however, when applications need to use
         prefixes in character data or in attribute values, where they
         cannot safely be expanded automatically; the
         start/endPrefixMapping event supplies the information to the
         application to expand prefixes in those contexts itself, if
         necessary.

         Note that start/endPrefixMapping events are not guaranteed to
         be properly nested relative to each-other: all
         startPrefixMapping events will occur before the corresponding
         startElement event, and all endPrefixMapping events will occur
         after the corresponding endElement event, but their order is
         not guaranteed."""

     def endPrefixMapping(self, prefix):
         """End the scope of a prefix-URI mapping.

         See startPrefixMapping for details. This event will always
         occur after the corresponding endElement event, but the order
         of endPrefixMapping events is not otherwise guaranteed."""

     def startElement(self, name, attrs):
         """Signals the start of an element in non-namespace mode.

         The name parameter contains the raw XML 1.0 name of the
         element type as a string and the attrs parameter holds an
         instance of the Attributes class containing the attributes of
         the element."""

     def endElement(self, name):
         """Signals the end of an element in non-namespace mode.

         The name parameter contains the name of the element type, just
         as with the startElement event."""

     def startElementNS(self, name, qname, attrs):
         """Signals the start of an element in namespace mode.

         The name parameter contains the name of the element type as a
         (uri, localname) tuple, the qname parameter the raw XML 1.0
         name used in the source document, and the attrs parameter
         holds an instance of the Attributes class containing the
         attributes of the element."""

     def endElementNS(self, name, qname):
         """Signals the end of an element in namespace mode.

         The name parameter contains the name of the element type, just
         as with the startElementNS event."""

     def characters(self, content):
         """Receive notification of character data.

         The Parser will call this method to report each chunk of
         character data. SAX parsers may return all contiguous
         character data in a single chunk, or they may split it into
         several chunks; however, all of the characters in any single
         event must come from the same external entity so that the
         Locator provides useful information."""

     def ignorableWhitespace(self, whitespace):
         """Receive notification of ignorable whitespace in element content.

         Validating Parsers must use this method to report each chunk
         of ignorable whitespace (see the W3C XML 1.0 recommendation,
         section 2.10): non-validating parsers may also use this method
         if they are capable of parsing and using content models.

         SAX parsers may return all contiguous whitespace in a single
         chunk, or they may split it into several chunks; however, all
         of the characters in any single event must come from the same
         external entity, so that the Locator provides useful
         information.

         The application must not attempt to read from the array
         outside of the specified range."""

     def processingInstruction(self, target, data):
         """Receive notification of a processing instruction.

         The Parser will invoke this method once for each processing
         instruction found: note that processing instructions may occur
         before or after the main document element.

         A SAX parser should never report an XML declaration (XML 1.0,
         section 2.8) or a text declaration (XML 1.0, section 4.3.1)
         using this method."""

     def skippedEntity(self, name):
         """Receive notification of a skipped entity.

         The Parser will invoke this method once for each entity
         skipped. Non-validating processors may skip entities if they
         have not seen the declarations (because, for example, the
         entity was declared in an external DTD subset). All processors
         may skip external entities, depending on the values of the
         http://xml.org/sax/features/external-general-entities and the
         http://xml.org/sax/features/external-parameter-entities
         properties."""


 # ===== DTDHandler =====

 class DTDHandler:
     """Handle DTD events.

     This interface specifies only those DTD events required for basic
     parsing (unparsed entities and attributes)."""

     def notationDecl(self, name, publicId, systemId):
         "Handle a notation declaration event."

     def unparsedEntityDecl(self, name, publicId, systemId, ndata):
         "Handle an unparsed entity declaration event."


 # ===== ENTITYRESOLVER =====

 class EntityResolver:
     """Basic interface for resolving entities. If you create an object
     implementing this interface, then register the object with your
     Parser, the parser will call the method in your object to
     resolve all external entities. Note that DefaultHandler implements
     this interface with the default behaviour."""

     def resolveEntity(self, publicId, systemId):
         """Resolve the system identifier of an entity and return either
         the system identifier to read from as a string, or an InputSource
         to read from."""
         return systemId


 #============================================================================
 #
 # CORE FEATURES
 #
 #============================================================================

 feature_namespaces = "http://xml.org/sax/features/namespaces"
 # true: Perform Namespace processing (default).
 # false: Optionally do not perform Namespace processing
 #        (implies namespace-prefixes).
 # access: (parsing) read-only; (not parsing) read/write

 feature_namespace_prefixes = "http://xml.org/sax/features/namespace-prefixes"
 # true: Report the original prefixed names and attributes used for Namespace
 #       declarations.
 # false: Do not report attributes used for Namespace declarations, and
 #        optionally do not report original prefixed names (default).
 # access: (parsing) read-only; (not parsing) read/write

 feature_string_interning = "http://xml.org/sax/features/string-interning"
 # true: All element names, prefixes, attribute names, Namespace URIs, and
 #       local names are interned using the built-in intern function.
 # false: Names are not necessarily interned, although they may be (default).
 # access: (parsing) read-only; (not parsing) read/write

 feature_validation = "http://xml.org/sax/features/validation"
 # true: Report all validation errors (implies external-general-entities and
 #       external-parameter-entities).
 # false: Do not report validation errors.
 # access: (parsing) read-only; (not parsing) read/write

 feature_external_ges = "http://xml.org/sax/features/external-general-entities"
 # true: Include all external general (text) entities.
 # false: Do not include external general entities.
 # access: (parsing) read-only; (not parsing) read/write

 feature_external_pes = "http://xml.org/sax/features/external-parameter-entities"
 # true: Include all external parameter entities, including the external
 #       DTD subset.
 # false: Do not include any external parameter entities, even the external
 #        DTD subset.
 # access: (parsing) read-only; (not parsing) read/write

 all_features = [feature_namespaces,
                 feature_namespace_prefixes,
                 feature_string_interning,
                 feature_validation,
                 feature_external_ges,
                 feature_external_pes]


 #============================================================================
 #
 # CORE PROPERTIES
 #
 #============================================================================

 property_lexical_handler = "http://xml.org/sax/properties/lexical-handler"
 # data type: xml.sax.sax2lib.LexicalHandler
 # description: An optional extension handler for lexical events like comments.
 # access: read/write

 property_declaration_handler = "http://xml.org/sax/properties/declaration-handler"
 # data type: xml.sax.sax2lib.DeclHandler
 # description: An optional extension handler for DTD-related events other
 #              than notations and unparsed entities.
 # access: read/write

 property_dom_node = "http://xml.org/sax/properties/dom-node"
 # data type: org.w3c.dom.Node
 # description: When parsing, the current DOM node being visited if this is
 #              a DOM iterator; when not parsing, the root DOM node for
 #              iteration.
 # access: (parsing) read-only; (not parsing) read/write

 property_xml_string = "http://xml.org/sax/properties/xml-string"
 # data type: String
 # description: The literal string of characters that was the source for
 #              the current event.
 # access: read-only

 all_properties = [property_lexical_handler,
                   property_dom_node,
                   property_declaration_handler,
                   property_xml_string]
	"""
	This module contains the core classes of version 2.0 of SAX for Python.
	This file provides only default classes with absolutely minimum
	functionality, from which drivers and applications can be subclassed.

	Many of these classes are empty and are included only as documentation
	of the interfaces.

	$Id$
	"""

	version = '2.0beta'

	#============================================================================
	#
	# HANDLER INTERFACES
	#
	#============================================================================

	# ===== ERRORHANDLER =====

	class ErrorHandler:
	"""Basic interface for SAX error handlers.

	If you create an object that implements this interface, then
	register the object with your XMLReader, the parser will call the
	methods in your object to report all warnings and errors. There
	are three levels of errors available: warnings, (possibly)
	recoverable errors, and unrecoverable errors. All methods take a
	SAXParseException as the only parameter."""

	def error(self, exception):
	"Handle a recoverable error."
	raise exception

	def fatalError(self, exception):
	"Handle a non-recoverable error."
	raise exception

	def warning(self, exception):
	"Handle a warning."
	print exception


	# ===== CONTENTHANDLER =====

	class ContentHandler:
	"""Interface for receiving logical document content events.

	This is the main callback interface in SAX, and the one most
	important to applications. The order of events in this interface
	mirrors the order of the information in the document."""

	def __init__(self):
	self._locator = None

	def setDocumentLocator(self, locator):
	"""Called by the parser to give the application a locator for
	locating the origin of document events.

	SAX parsers are strongly encouraged (though not absolutely
	required) to supply a locator: if it does so, it must supply
	the locator to the application by invoking this method before
	invoking any of the other methods in the DocumentHandler
	interface.

	The locator allows the application to determine the end
	position of any document-related event, even if the parser is
	not reporting an error. Typically, the application will use
	this information for reporting its own errors (such as
	character content that does not match an application's
	business rules). The information returned by the locator is
	probably not sufficient for use with a search engine.

	Note that the locator will return correct information only
	during the invocation of the events in this interface. The
	application should not attempt to use it at any other time."""
	self._locator = locator

	def startDocument(self):
	"""Receive notification of the beginning of a document.

	The SAX parser will invoke this method only once, before any
	other methods in this interface or in DTDHandler (except for
	setDocumentLocator)."""

	def endDocument(self):
	"""Receive notification of the end of a document.

	The SAX parser will invoke this method only once, and it will
	be the last method invoked during the parse. The parser shall
	not invoke this method until it has either abandoned parsing
	(because of an unrecoverable error) or reached the end of
	input."""

	def startPrefixMapping(self, prefix, uri):
	"""Begin the scope of a prefix-URI Namespace mapping.

	The information from this event is not necessary for normal
	Namespace processing: the SAX XML reader will automatically
	replace prefixes for element and attribute names when the
	http://xml.org/sax/features/namespaces feature is true (the
	default).

	There are cases, however, when applications need to use
	prefixes in character data or in attribute values, where they
	cannot safely be expanded automatically; the
	start/endPrefixMapping event supplies the information to the
	application to expand prefixes in those contexts itself, if
	necessary.

	Note that start/endPrefixMapping events are not guaranteed to
	be properly nested relative to each-other: all
	startPrefixMapping events will occur before the corresponding
	startElement event, and all endPrefixMapping events will occur
	after the corresponding endElement event, but their order is
	not guaranteed."""

	def endPrefixMapping(self, prefix):
	"""End the scope of a prefix-URI mapping.

	See startPrefixMapping for details. This event will always
	occur after the corresponding endElement event, but the order
	of endPrefixMapping events is not otherwise guaranteed."""

	def startElement(self, name, attrs):
	"""Signals the start of an element in non-namespace mode.

	The name parameter contains the raw XML 1.0 name of the
	element type as a string and the attrs parameter holds an
	instance of the Attributes class containing the attributes of
	the element."""

	def endElement(self, name):
	"""Signals the end of an element in non-namespace mode.

	The name parameter contains the name of the element type, just
	as with the startElement event."""

	def startElementNS(self, name, qname, attrs):
	"""Signals the start of an element in namespace mode.

	The name parameter contains the name of the element type as a
	(uri, localname) tuple, the qname parameter the raw XML 1.0
	name used in the source document, and the attrs parameter
	holds an instance of the Attributes class containing the
	attributes of the element."""

	def endElementNS(self, name, qname):
	"""Signals the end of an element in namespace mode.

	The name parameter contains the name of the element type, just
	as with the startElementNS event."""

	def characters(self, content):
	"""Receive notification of character data.

	The Parser will call this method to report each chunk of
	character data. SAX parsers may return all contiguous
	character data in a single chunk, or they may split it into
	several chunks; however, all of the characters in any single
	event must come from the same external entity so that the
	Locator provides useful information."""

	def ignorableWhitespace(self, whitespace):
	"""Receive notification of ignorable whitespace in element content.

	Validating Parsers must use this method to report each chunk
	of ignorable whitespace (see the W3C XML 1.0 recommendation,
	section 2.10): non-validating parsers may also use this method
	if they are capable of parsing and using content models.

	SAX parsers may return all contiguous whitespace in a single
	chunk, or they may split it into several chunks; however, all
	of the characters in any single event must come from the same
	external entity, so that the Locator provides useful
	information.

	The application must not attempt to read from the array
	outside of the specified range."""

	def processingInstruction(self, target, data):
	"""Receive notification of a processing instruction.

	The Parser will invoke this method once for each processing
	instruction found: note that processing instructions may occur
	before or after the main document element.

	A SAX parser should never report an XML declaration (XML 1.0,
	section 2.8) or a text declaration (XML 1.0, section 4.3.1)
	using this method."""

	def skippedEntity(self, name):
	"""Receive notification of a skipped entity.

	The Parser will invoke this method once for each entity
	skipped. Non-validating processors may skip entities if they
	have not seen the declarations (because, for example, the
	entity was declared in an external DTD subset). All processors
	may skip external entities, depending on the values of the
	http://xml.org/sax/features/external-general-entities and the
	http://xml.org/sax/features/external-parameter-entities
	properties."""


	# ===== DTDHandler =====

	class DTDHandler:
	"""Handle DTD events.

	This interface specifies only those DTD events required for basic
	parsing (unparsed entities and attributes)."""

	def notationDecl(self, name, publicId, systemId):
	"Handle a notation declaration event."

	def unparsedEntityDecl(self, name, publicId, systemId, ndata):
	"Handle an unparsed entity declaration event."


	# ===== ENTITYRESOLVER =====

	class EntityResolver:
	"""Basic interface for resolving entities. If you create an object
	implementing this interface, then register the object with your
	Parser, the parser will call the method in your object to
	resolve all external entities. Note that DefaultHandler implements
	this interface with the default behaviour."""

	def resolveEntity(self, publicId, systemId):
	"""Resolve the system identifier of an entity and return either
	the system identifier to read from as a string, or an InputSource
	to read from."""
	return systemId


	#============================================================================
	#
	# CORE FEATURES
	#
	#============================================================================

	feature_namespaces = "http://xml.org/sax/features/namespaces"
	# true: Perform Namespace processing (default).
	# false: Optionally do not perform Namespace processing
	# (implies namespace-prefixes).
	# access: (parsing) read-only; (not parsing) read/write

	feature_namespace_prefixes = "http://xml.org/sax/features/namespace-prefixes"
	# true: Report the original prefixed names and attributes used for Namespace
	# declarations.
	# false: Do not report attributes used for Namespace declarations, and
	# optionally do not report original prefixed names (default).
	# access: (parsing) read-only; (not parsing) read/write

	feature_string_interning = "http://xml.org/sax/features/string-interning"
	# true: All element names, prefixes, attribute names, Namespace URIs, and
	# local names are interned using the built-in intern function.
	# false: Names are not necessarily interned, although they may be (default).
	# access: (parsing) read-only; (not parsing) read/write

	feature_validation = "http://xml.org/sax/features/validation"
	# true: Report all validation errors (implies external-general-entities and
	# external-parameter-entities).
	# false: Do not report validation errors.
	# access: (parsing) read-only; (not parsing) read/write

	feature_external_ges = "http://xml.org/sax/features/external-general-entities"
	# true: Include all external general (text) entities.
	# false: Do not include external general entities.
	# access: (parsing) read-only; (not parsing) read/write

	feature_external_pes = "http://xml.org/sax/features/external-parameter-entities"
	# true: Include all external parameter entities, including the external
	# DTD subset.
	# false: Do not include any external parameter entities, even the external
	# DTD subset.
	# access: (parsing) read-only; (not parsing) read/write

	all_features = [feature_namespaces,
	feature_namespace_prefixes,
	feature_string_interning,
	feature_validation,
	feature_external_ges,
	feature_external_pes]


	#============================================================================
	#
	# CORE PROPERTIES
	#
	#============================================================================

	property_lexical_handler = "http://xml.org/sax/properties/lexical-handler"
	# data type: xml.sax.sax2lib.LexicalHandler
	# description: An optional extension handler for lexical events like comments.
	# access: read/write

	property_declaration_handler = "http://xml.org/sax/properties/declaration-handler"
	# data type: xml.sax.sax2lib.DeclHandler
	# description: An optional extension handler for DTD-related events other
	# than notations and unparsed entities.
	# access: read/write

	property_dom_node = "http://xml.org/sax/properties/dom-node"
	# data type: org.w3c.dom.Node
	# description: When parsing, the current DOM node being visited if this is
	# a DOM iterator; when not parsing, the root DOM node for
	# iteration.
	# access: (parsing) read-only; (not parsing) read/write

	property_xml_string = "http://xml.org/sax/properties/xml-string"
	# data type: String
	# description: The literal string of characters that was the source for
	# the current event.
	# access: read-only

	all_properties = [property_lexical_handler,
	property_dom_node,
	property_declaration_handler,
	property_xml_string]