"""
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.

 The uri part of the name tuple is None for elements which have
 no namespace."""

 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."""

 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

property_encoding = "http://www.python.org/sax/properties/encoding"
# data type: String
# description: The name of the encoding to assume for input data.
# access: write: set the encoding, e.g. established by a higher-level
# protocol. May change during parsing (e.g. after
# processing a META tag)
# read: return the current encoding (possibly established through
# auto-detection.
# initial value: UTF-8
#

property_interning_dict = "http://www.python.org/sax/properties/interning-dict"
# data type: Dictionary
# description: The dictionary used to intern common strings in the document
# access: write: Request that the parser uses a specific dictionary, to
# allow interning across different documents
# read: return the current interning dictionary, or None
#

all_properties = [property_lexical_handler,
 property_dom_node,
 property_declaration_handler,
 property_xml_string,
 property_encoding,
 property_interning_dict]