object for the JSP page where the tag is located; this object can be used
to access defined objects.
tag handler for the enclosing action.
A tag handler may have additional properties, as any other JavaBean component. These
properties will have setters and getter methods, as described in the JavaBeans component
specification, and used throughout the Java platform.
All attributes of a custom action must be JavaBeans component properties, although some
properties may not be exposed as attributes in the Tag Library Descriptor.
Additional translation time information (
) associated with the action
indicates the name of the variables it introduces, their types and their scope. At specific
moments (after processing the start tag; after processing the end tag), the JSP container can
automatically synchronize the PageContext information with variables in the scripting
language so they can be made available directly through the scripting elements.
Basic Protocol: Tag Interface
This section describes the
interface which defines the basic contract for all tag handlers.
See Section 5.4.7 for a summary of the life cycle issues.
A tag handler has some
that must be initialized before it can be used. It is the
responsibility of the JSP container to invoke the appropriate setter methods to initialize these
properties. Once properly set, these properties are expected to be persistent, so that if the
JSP container ascertains that a property has already been set on a given tag handler instance,
it needs not set it again. These properties include the properties in the Tag interface as well
as other properties
Once initialized, the
methods can be invoked on the tag
handler. Between these invocations, the tag handler is assumed to hold a state that must be
preserved. After the
invocation, the tag handler is available for further
invocations (and it is expected to have retained its properties). Once all invocations on the
tag handler are completed, the
method is invoked on it. Once a
is invoked all properties are assumed to have been reset to an unspecified value.
All tag handlers must have the following properties: pageContext, and parent. When setting
properties, the order is always
pageContext and parent.
interface specifies the setter
methods for all properties, and the getter method for parent.
Sets the pageContext property of a tag handler.
Sets the parent Tag for a tag handler.
JavaServer Pages 1.1 Specification
November 30, 1999