javax.servlet.jsp.tagext
Class TagExtraInfo
java.lang.Objectjavax.servlet.jsp.tagext.TagExtraInfo
public abstract class TagExtraInfo
extends java.lang.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().
TagExtraInfo
public TagExtraInfo()
Sole constructor. (For invocation by subclass constructors,
typically implicit.)
getTagInfo
public final TagInfo getTagInfo()
Get the TagInfo for this class.
- the taginfo instance this instance is extending
getVariableInfo
public VariableInfo[] getVariableInfo(TagData data)
information on scripting variables defined by the tag associated with
this TagExtraInfo instance.
Request-time attributes are indicated as such in the TagData parameter.
data - The TagData instance.
- An array of VariableInfo data, or null or a zero length array
if no scripting variables are to be defined.
isValid
public boolean isValid(TagData data)
Translation-time validation of the attributes.
Request-time attributes are indicated as such in the TagData parameter.
Note that the preferred way to do validation is with the validate()
method, since it can return more detailed information.
data - The TagData instance.
- Whether this tag instance is valid.
setTagInfo
public final void setTagInfo(TagInfo tagInfo)
Set the TagInfo for this class.
tagInfo - The TagInfo this instance is extending
validate
public ValidationMessage[] validate(TagData data)
Translation-time validation of the attributes.
Request-time attributes are indicated as such in the TagData parameter.
Because of the higher quality validation messages possible,
this is the preferred way to do validation (although isValid()
still works).
JSP 2.0 and higher containers call validate() instead of isValid().
The default implementation of this method is to call isValid(). If
isValid() returns false, a generic ValidationMessage[] is returned
indicating isValid() returned false.
data - The TagData instance.
- A null object, or zero length array if no errors, an
array of ValidationMessages otherwise.
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