com.programix.saxplus
Class BaseTagHandler

java.lang.Object
  com.programix.saxplus.BaseTagHandler

All Implemented Interfaces:

TagHandler

Direct Known Subclasses:

SimpleTagHandler

public abstract class BaseTagHandler
extends Object
implements TagHandler

Implements all methods of TagHandler and can serve as a class to extend for your TagHandler's. In your subclass, just override the methods that you are interested in.

BaseTagHandler also supports a name-handler mapping for all of the sub-tags of a tag (see setSubTagHandler(String, TagHandler) and setSubTagHandler(NameDetail, TagHandler)). Therefore, the implementation of startSubTag(NameDetail) rarely needs to be overridden.

Author:

Paul Hyde

Constructor Summary

protected

BaseTagHandler()

Method Summary

void	endSubTag(NameDetail subTagName, Value subTagResult) Called after a sub tag has completed.
void	endTag()
Value	getResult() This implementation returns ValueFactory.NULL_INSTANCE.
protected TagHandler	getSubTagHandler(NameDetail tagName) Pulls of the plain name (using NameDetail.getName()) and calls getSubTagHandler(String).
protected TagHandler	getSubTagHandler(String tagName) Returns the handler for the specified tag, or null if no handler is found for the name.
protected void	setSubTagHandler(NameDetail tagName, TagHandler handler) Pulls of the plain name (using NameDetail.getName()) and calls setSubTagHandler(String, TagHandler).
protected void	setSubTagHandler(String tagName, TagHandler handler)
TagHandler	startSubTag(NameDetail subTagName) This implementation returns whatever getSubTagHandler(NameDetail) finds for the specified sub tag.
void	startTag(NameDetail tagName, AttributeGroup attr)
void	text(Value tagText) Delivers textual content within this tag.

Methods inherited from class java.lang.Object

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

Constructor Detail

BaseTagHandler

protected BaseTagHandler()

Method Detail

setSubTagHandler

protected void setSubTagHandler(String tagName,
                                TagHandler handler)

setSubTagHandler

protected void setSubTagHandler(NameDetail tagName,
                                TagHandler handler)

Pulls of the plain name (using NameDetail.getName()) and calls setSubTagHandler(String, TagHandler).

getSubTagHandler

protected TagHandler getSubTagHandler(String tagName)

Returns the handler for the specified tag, or null if no handler is found for the name.

getSubTagHandler

protected TagHandler getSubTagHandler(NameDetail tagName)

Pulls of the plain name (using NameDetail.getName()) and calls getSubTagHandler(String).

startTag

public void startTag(NameDetail tagName,
                     AttributeGroup attr)
              throws SAXException

Specified by:

startTag in interface TagHandler

Throws:

SAXException

endTag

public void endTag()
            throws SAXException

Specified by:

endTag in interface TagHandler

Throws:

SAXException

text

public void text(Value tagText)
          throws SAXException

Description copied from interface: TagHandler

Delivers textual content within this tag. If this tag has no sub tags, then this method is called at most once. If this tag is empty or has no text other than whitespace, this method is not called. If this tag has sub tags and only whitespace between the sub tags, this method is not called. If there is a mixture of (non-whitespace) text and sub tags, this method is called multiple times.

For example:

 <apple>
     <excellent>Red Delicious</excellent>
     <good>Granny Smith</good>
 </apple>
 <fresh value="yes" />
 <mango>
      </mango>
 <story>They are <bold>very</bold> tasty.</story>
 

The text() method is called:

• exactly one time for excellent (no sub tags).
• never for apple (only sub tags and whitespace).
• never for fresh (empty element).
• never for mango (only whitespace).
• two times for story (once for "They are " and a second time for " tasty." ["very" is passed to the text() for the tag handler for bold, not for story.]

Specified by:

text in interface TagHandler

Throws:

SAXException

startSubTag

public TagHandler startSubTag(NameDetail subTagName)
                       throws SAXException

This implementation returns whatever getSubTagHandler(NameDetail) finds for the specified sub tag. If no sub tag handler is found, then null is returned, indicating that the sub tag is ignored. Overridden by subclasses as appropriate.

Specified by:

startSubTag in interface TagHandler

Throws:

SAXException

endSubTag

public void endSubTag(NameDetail subTagName,
                      Value subTagResult)
               throws SAXException

Description copied from interface: TagHandler

Called after a sub tag has completed.

Specified by:

endSubTag in interface TagHandler

Throws:

SAXException

getResult

public Value getResult()
                throws SAXException

This implementation returns ValueFactory.NULL_INSTANCE. Overridden by subclasses as appropriate.

Specified by:

getResult in interface TagHandler

Returns:

the value calculated, never null.

Throws:

SAXException - if the result can not be assembled (e.g. a required piece of data is missing).