Class TagExtraInfo


public abstract class TagExtraInfo extends Object
Optional class provided by the tag library author to describe additional translation-time information not described in the TLD. The TagExtraInfo class is mentioned in the Tag Library Descriptor file (TLD).

This class can be used:

  • to indicate that the tag defines scripting variables
  • to perform translation-time validation of the tag attributes.

It is the responsibility of the JSP translator that the initial value to be returned by calls to getTagInfo() corresponds to a TagInfo object for the tag being translated. If an explicit call to setTagInfo() is done, then the object passed will be returned in subsequent calls to getTagInfo().

The only way to affect the value returned by getTagInfo() is through a setTagInfo() call, and thus, TagExtraInfo.setTagInfo() is to be called by the JSP translator, with a TagInfo object that corresponds to the tag being translated. The call should happen before any invocation on validate() and before any invocation on getVariableInfo().

NOTE: It is a (translation time) error for a tag definition in a TLD with one or more variable subelements to have an associated TagExtraInfo implementation that returns a VariableInfo array with one or more elements from a call to getVariableInfo().