com.tridion.tcdl

Interface TagHandlerBase

All Known Subinterfaces:

TagHandler, TagRenderer

All Known Implementing Classes:

CommentTagRenderer, ComponentPresentationTagRenderer, ContentHeaderTagRenderer, ContextPropertyTagRenderer, DefaultTagHandler, DefaultTagRenderer, FirstLineTagRenderer, LinkTagRenderer, PositionMarkerTagRenderer, TaxonomyTagRenderer

public interface TagHandlerBase

Defines minimal requirements for a TagHandler. Either a 'transformer' or a 'renderer'.

Method Summary

Modifier and Type	Method and Description
String	doEndTag(Tag tag, StringBuffer tagBody, TransformContext context, OutputDocument target) Called whenever an ending Tag that is associated with the handler is encountered in TCDL content.
int	doStartTag(Tag tag, StringBuffer tagBody, TransformContext context, OutputDocument target) Called whenever as starting Tag that is associated with the handler is encountered in TCDL content.
boolean	requiresCodeBlock(TransformContext context, OutputDocument target, Tag tag) This method is called right before doStartTag and its return value indicates if the engine must wrap the result of doEndTag inside a code block.

Method Detail

doStartTag

int doStartTag(Tag tag,
               StringBuffer tagBody,
               TransformContext context,
               OutputDocument target)
        throws TCDLTransformerException

Called whenever as starting Tag that is associated with the handler is encountered in TCDL content. At the very least the start tag must indicate if processing the tag contents should proceed, by returning either Tag.CONTINUE_TAG_EVALUATION or Tag.SKIP_TAG When SKIP_TAG is returned, doEndTag will not be called.

It is possible to prepend data to the tagContents using the [tagBody] buffer. The tagBody StringBuffer collects the content occurring (or generated by nested tags) between the start and closing tag.

Parameters:

tag - The fully initialized tag

tagBody - Buffer that will be used by the framework to write tag content to.

context - TransformContext offering access to context attributes

target - OutputDocument for setting supporting information to build the final document

Returns:

control code of the tag flow. Currently only Tag.CONTINUE_TAG_EVALUATION or Tag.SKIP_TAG

Throws:

TCDLTransformerException - On problems transforming the TCDL.

TCDLTransformerException

doEndTag

String doEndTag(Tag tag,
                StringBuffer tagBody,
                TransformContext context,
                OutputDocument target)
         throws TCDLTransformerException

Called whenever an ending Tag that is associated with the handler is encountered in TCDL content. The primary responsibility of this method is to generate the tag contents that will be embedded in the output document. This is done by returning the proper value. The tagBody will contain all element data that occurred between the start/end tag as well as data that was written by the doStartTag method of this handler. E.g. return tagBody.toString() would simply return the content that was encountered between the start/end tag (as well as resolved content of nested tags).

Note that the Tag [tag] parameter will have all attributes set of the start tag (in fact it is the start tag), so all information of the tag is at your disposal.

Parameters:

tag - The fully initialized tag

tagBody - Buffer that will be used by the framework to write tag content to.

context - TransformContext offering access to context attributes

target - OutputDocument for setting supporting information to build the final document

Returns:

control code of the tag flow. Currently only Tag.CONTINUE_TAG_EVALUATION or Tag.SKIP_TAG

Throws:

TCDLTransformerException - On problems transforming the TCDL.

TCDLTransformerException

requiresCodeBlock

boolean requiresCodeBlock(TransformContext context,
                          OutputDocument target,
                          Tag tag)

This method is called right before doStartTag and its return value indicates if the engine must wrap the result of doEndTag inside a code block.

The start [tag] is passed, so the handler may use attribute values to decide upon it's result

Parameters:

context - TransformContext offering access to context attributes

target - OutputDocument for setting supporting information to build the final document

tag - The fully initialized tag

Returns:

Whether or not it requires a code block.