Simple Actions with non empty Bodies
If a tag library descriptor maps an action with a non empty body to a tag handler that
interface, the tag handler cannot
this body because there is
no mechanism for the tag handler to access that body. To make the situation more explicit,
the return value of
is either SKIP_BODY, EVAL_BODY_INCLUDE or
EVAL_BODY_TAG. The meanings are as follows:
SKIP_BODY means do not process the body of the action (if it exists).
EVAL_BODY_INCLUDE means process the body of the action but do not create a new
BodyContent (see below) nor change the value of the out implicit object.
EVAL_BODY_TAG means create a new
, change the value of the out
implicit object and process the body of the action.
A typical use for EVAL_BODY_INCLUDE could be a conditional inclusion action tag.
Since the body is to be passed through directly, there is no need for the tag handler to
manipulate it, and thus the tag handler needs not implement
To help in catching errors, EVAL_BODY_INCLUDE is not valid in a tag handler that
, while EVAL_BODY_TAG is not valid in a tag handler that
but does not implement BodyTag.
The TagSupport Base Class
class is a utility class intended to be used as the base class for new tag
handlers. The TagSupport class implements the
interface and adds additional
convenience methods including getter methods for the properties in
one static method that is included to facilitate coordination among cooperating tags.
Find the instance of a given class type that is closest to a given instance. This
method uses the
method from the
The return value of the
. The return value of the
) method is
Body Protocol: BodyTag Interface
with methods to manipulate the body of an action.
These methods act on the
property of a
JavaServer Pages 1.1 Specification
November 30, 1999