org.xwiki.xml
Class ExtractHandler

java.lang.Object
  org.xml.sax.helpers.DefaultHandler
      org.xwiki.xml.ExtractHandler

All Implemented Interfaces:

ContentHandler, DTDHandler, EntityResolver, ErrorHandler

public class ExtractHandler
extends org.xml.sax.helpers.DefaultHandler

Extracts a well-formed XML fragment by listening to SAX events. The result has the following semantic:
xmlInput.dropAllTags().substring(start, length).unDropAssociatedTags()

So basically we would create an instance like new ExtractHandler(0, 400) in order to obtain an XML fragment with its inner text length of at most 400 characters, starting at position (character) 0 in the source (input) XML's inner text. The ExtractHandler is used in feed plug-in to obtain a preview of an XML (HTML, to be more specific). Another use case could be to paginate an XML source (keeping pages well-formed).

As an example, the result of applying an ExtractHandler(3, 13) to:
<p>click <a href="realyLongURL" title="Here">here</a> to view the result</p>
is:
<p>ck <a href="realyLongURL" title="Here">here</a> to</p>

Since:

1.6M2

Version:

$Id$

Constructor Summary

ExtractHandler(int start, int length)
Creates a new instance.

Method Summary

void	characters(char[] ch, int start, int length)
void	endDocument()
void	endElement(String namespaceURI, String localName, String qName)
String	getResult()
boolean	isFinished()
void	startDocument()
void	startElement(String namespaceURI, String localName, String qName, Attributes atts)

Methods inherited from class org.xml.sax.helpers.DefaultHandler

endPrefixMapping, error, fatalError, ignorableWhitespace, notationDecl, processingInstruction, resolveEntity, setDocumentLocator, skippedEntity, startPrefixMapping, unparsedEntityDecl, warning

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExtractHandler

public ExtractHandler(int start,
                      int length)
               throws SAXException

Creates a new instance.

Parameters:

start - The character index from where to start the extraction.

length - The number of plain text characters to extract.

Throws:

SAXException - if start is less than zero or length is less than or equal to zero.

Method Detail

getResult

public String getResult()

Returns:

The extracted text.

isFinished

public boolean isFinished()

Returns:

true if the extraction process has succeeded; false if an exception occurred during the process.

startDocument

public void startDocument()
                   throws SAXException

Specified by:

startDocument in interface ContentHandler

Overrides:

startDocument in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

See Also:

DefaultHandler.startDocument()

startElement

public void startElement(String namespaceURI,
                         String localName,
                         String qName,
                         Attributes atts)
                  throws SAXException

Specified by:

startElement in interface ContentHandler

Overrides:

startElement in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

See Also:

DefaultHandler.startElement(String, String, String, Attributes)

characters

public void characters(char[] ch,
                       int start,
                       int length)
                throws SAXException

Specified by:

characters in interface ContentHandler

Overrides:

characters in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

See Also:

DefaultHandler.characters(char[], int, int)

endElement

public void endElement(String namespaceURI,
                       String localName,
                       String qName)
                throws SAXException

Specified by:

endElement in interface ContentHandler

Overrides:

endElement in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

See Also:

DefaultHandler.endElement(String, String, String)

endDocument

public void endDocument()
                 throws SAXException

Specified by:

endDocument in interface ContentHandler

Overrides:

endDocument in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

See Also:

DefaultHandler.endDocument()