Class Summary : TDefaultHandler

Default base class for SAX2 event handlers.
This module, both source code and documentation, is in the Public Domain, and comes with NO WARRANTY.

This class is available as a convenience base class for SAX2 applications: it provides default implementations for all of the callbacks in the four core SAX2 handler classes:

Application writers can extend this class when they need to implement only part of an interface; parser writers can instantiate this class to provide default handlers when the application has not supplied its own.

This class replaces the deprecated SAX1 HandlerBase class.


Since : SAX 2.0
See : IEntityResolver
See : IDTDHandler
See : IContentHandler
See : IErrorHandler

Methods

function resolveEntity(SAXString, SAXString) : IInputSource
procedure notationDecl(SAXString, SAXString, SAXString)
procedure unparsedEntityDecl(SAXString, SAXString, SAXString, SAXString)
procedure setDocumentLocator(ILocator)
procedure startDocument()
procedure endDocument()
procedure startPrefixMapping(SAXString, SAXString)
procedure endPrefixMapping(SAXString)
procedure startElement(SAXString, SAXString, SAXString, IAttributes)
procedure endElement(SAXString, SAXString, SAXString)
procedure characters(SAXString)
procedure ignorableWhitespace(SAXString)
procedure processingInstruction(SAXString, SAXString)
procedure skippedEntity(SAXString)
procedure warning(ISAXParseError)
procedure error(ISAXParseError)
procedure fatalError(ISAXParseError)


function resolveEntity(const publicId : SAXString; const systemId : SAXString) : IInputSource;

Resolve an external entity.

Always return nil, so that the parser will use the system identifier provided in the XML document. This method implements the SAX default behaviour: application writers can override it in a subclass to do special translations such as catalog lookups or URI redirection.


Parameter : publicId The public identifer, or an empty string if none is available.
Parameter : systemId The system identifier provided in the XML document.
Result : The new input source, or nil to require the default behaviour.
Exception : ESAXException Any SAX exception.
See : IEntityResolver.resolveEntity

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procedure notationDecl(const name : SAXString; const publicId : SAXString; const systemId : SAXString);

Receive notification of a notation declaration.

By default, do nothing. Application writers may override this method in a subclass if they wish to keep track of the notations declared in a document.


Parameter : name The notation name.
Parameter : publicId The notation public identifier, or an empty string if not available.
Parameter : systemId The notation system identifier.
Exception : ESAXException Any SAX exception.
See : IDTDHandler.notationDecl

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procedure unparsedEntityDecl(const name : SAXString; const publicId : SAXString; const systemId : SAXString; const notationName : SAXString);

Receive notification of an unparsed entity declaration.

By default, do nothing. Application writers may override this method in a subclass to keep track of the unparsed entities declared in a document.


Parameter : name The entity name.
Parameter : publicId The entity public identifier, or an empty string if not available.
Parameter : systemId The entity system identifier.
Parameter : notationName The name of the associated notation.
Exception : ESAXException Any SAX exception.
See : IDTDHandler.unparsedEntityDecl

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procedure setDocumentLocator(const Locator : ILocator);

Receive a Locator object for document events.

By default, do nothing. Application writers may override this method in a subclass if they wish to store the locator for use with other document events.


Parameter : locator A locator for all SAX document events.
See : IContentHandler.setDocumentLocator
See : ILocator

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procedure startDocument();

Receive notification of the beginning of the document.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the beginning of a document (such as allocating the root node of a tree or creating an output file).


Exception : ESAXException Any SAX exception.
See : IContentHandler.startDocument

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procedure endDocument();

Receive notification of the end of the document.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the end of a document (such as finalising a tree or closing an output file).


Exception : ESAXException Any SAX exception
See : IContentHandler.endDocument

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procedure startPrefixMapping(const prefix : SAXString; const uri : SAXString);

Receive notification of the start of a Namespace mapping.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the start of each Namespace prefix scope (such as storing the prefix mapping).


Parameter : prefix The Namespace prefix being declared.
Parameter : uri The Namespace URI mapped to the prefix.
Exception : ESAXException Any SAX exception.
See : IContentHandler.startPrefixMapping

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procedure endPrefixMapping(const prefix : SAXString);

Receive notification of the end of a Namespace mapping.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the end of each prefix mapping.


Parameter : prefix The Namespace prefix being declared.
Exception : ESAXException Any SAX exception.
See : IContentHandler.endPrefixMapping

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procedure startElement(const uri : SAXString; const localName : SAXString; const qName : SAXString; const atts : IAttributes);

Receive notification of the start of an element.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the start of each element (such as allocating a new tree node or writing output to a file).


Parameter : uri The Namespace URI, or the empty string if the element has no Namespace URI or if Namespace processing is not being performed.
Parameter : localName The local name (without prefix), or the empty string if Namespace processing is not being performed.
Parameter : qName The qualified name (with prefix), or the empty string if qualified names are not available.
Parameter : atts The attributes attached to the element. If there are no attributes, it shall be an empty Attributes object.
Exception : ESAXException Any SAX exception.
See : IContentHandler.startElement

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procedure endElement(const uri : SAXString; const localName : SAXString; const qName : SAXString);

Receive notification of the end of an element.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the end of each element (such as finalising a tree node or writing output to a file).


Parameter : uri The Namespace URI, or the empty string if the element has no Namespace URI or if Namespace processing is not being performed.
Parameter : localName The local name (without prefix), or the empty string if Namespace processing is not being performed.
Parameter : qName The qualified name (with prefix), or the empty string if qualified names are not available.
Exception : ESAXException Any SAX exception.
See : IContentHandler.endElement

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procedure characters(const ch : SAXString);

Receive notification of character data inside an element.

By default, do nothing. Application writers may override this method to take specific actions for each chunk of character data (such as adding the data to a node or buffer, or printing it to a file).


Parameter : ch The characters from the XML Document.
Exception : ESAXException Any SAX exception.
See : IContentHandler.characters

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procedure ignorableWhitespace(const ch : SAXString);

Receive notification of ignorable whitespace in element content.

By default, do nothing. Application writers may override this method to take specific actions for each chunk of ignorable whitespace (such as adding data to a node or buffer, or printing it to a file).


Parameter : ch The whitespace characters.
Exception : ESAXException Any SAX exception.
See : IContentHandler.ignorableWhitespace

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procedure processingInstruction(const target : SAXString; const data : SAXString);

Receive notification of a processing instruction.

By default, do nothing. Application writers may override this method in a subclass to take specific actions for each processing instruction, such as setting status variables or invoking other methods.


Parameter : target The processing instruction target.
Parameter : data The processing instruction data, or an empty string if none is supplied.
Exception : ESAXException Any SAX exception.
See : IContentHandler.processingInstruction

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procedure skippedEntity(const name : SAXString);

Receive notification of a skipped entity.

By default, do nothing. Application writers may override this method in a subclass to take specific actions for each processing instruction, such as setting status variables or invoking other methods.


Parameter : name The name of the skipped entity.
Exception : ESAXException Any SAX exception.
See : IContentHandler.processingInstruction

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procedure warning(const e : ISAXParseError);

Receive notification of a parser warning.

The default implementation does nothing. Application writers may override this method in a subclass to take specific actions for each warning, such as inserting the message in a log file or printing it to the console.


Parameter : e The warning information encoded as an exception.
Exception : ESAXException Any SAX exception.
See : IErrorHandler.warning
See : ESAXParseException

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procedure error(const e : ISAXParseError);

Receive notification of a recoverable parser error.

The default implementation does nothing. Application writers may override this method in a subclass to take specific actions for each error, such as inserting the message in a log file or printing it to the console.


Parameter : e The warning information encoded as an exception.
Exception : ESAXException Any SAX exception.
See : IErrorHandler.warning
See : ESAXParseException

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procedure fatalError(const e : ISAXParseError);

Report a fatal XML parsing error.

The default implementation throws a SAXParseException. Application writers may override this method in a subclass if they need to take specific actions for each fatal error (such as collecting all of the errors into a single report): in any case, the application must stop all regular processing when this method is invoked, since the document is no longer reliable, and the parser may no longer report parsing events.


Parameter : e The error information encoded as an exception.
Exception : ESAXException Any SAX exception.
See : IErrorHandler.fatalError
See : ESAXParseException

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