001 // XMLFilter.java - filter SAX2 events.
002 // http://www.saxproject.org
003 // Written by David Megginson
004 // NO WARRANTY! This class is in the Public Domain.
005 // $Id: XMLFilter.java,v 1.1 2004/12/23 22:38:42 mark Exp $
006
007 package org.xml.sax;
008
009
010 /**
011 * Interface for an XML filter.
012 *
013 * <blockquote>
014 * <em>This module, both source code and documentation, is in the
015 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
016 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
017 * for further information.
018 * </blockquote>
019 *
020 * <p>An XML filter is like an XML reader, except that it obtains its
021 * events from another XML reader rather than a primary source like
022 * an XML document or database. Filters can modify a stream of
023 * events as they pass on to the final application.</p>
024 *
025 * <p>The XMLFilterImpl helper class provides a convenient base
026 * for creating SAX2 filters, by passing on all {@link org.xml.sax.EntityResolver
027 * EntityResolver}, {@link org.xml.sax.DTDHandler DTDHandler},
028 * {@link org.xml.sax.ContentHandler ContentHandler} and {@link org.xml.sax.ErrorHandler
029 * ErrorHandler} events automatically.</p>
030 *
031 * @since SAX 2.0
032 * @author David Megginson
033 * @version 2.0.1 (sax2r2)
034 * @see org.xml.sax.helpers.XMLFilterImpl
035 */
036 public interface XMLFilter extends XMLReader
037 {
038
039 /**
040 * Set the parent reader.
041 *
042 * <p>This method allows the application to link the filter to
043 * a parent reader (which may be another filter). The argument
044 * may not be null.</p>
045 *
046 * @param parent The parent reader.
047 */
048 public abstract void setParent (XMLReader parent);
049
050
051 /**
052 * Get the parent reader.
053 *
054 * <p>This method allows the application to query the parent
055 * reader (which may be another filter). It is generally a
056 * bad idea to perform any operations on the parent reader
057 * directly: they should all pass through this filter.</p>
058 *
059 * @return The parent filter, or null if none has been set.
060 */
061 public abstract XMLReader getParent ();
062
063 }
064
065 // end of XMLFilter.java