javax.servlet.jsp.jstl.core

Class ConditionalTagSupport


public abstract class ConditionalTagSupport
extends TagSupport

Abstract class that facilitates implementation of conditional actions where the boolean result is exposed as a JSP scoped variable. The boolean result may then be used as the test condition in a <c:when> action.

This base class provides support for:

Author:
Shawn Bayern

Constructor Summary

ConditionalTagSupport()
Base constructor to initialize local state.

Method Summary

protected boolean
condition()
Subclasses implement this method to compute the boolean result of the conditional action.
int
doStartTag()
Includes its body if condition() evaluates to true.
void
release()
Releases any resources this ConditionalTagSupport may have (or inherit).
void
setScope(String scope)
Sets the 'scope' attribute.
void
setVar(String var)
Sets the 'var' attribute.

Constructor Details

ConditionalTagSupport

public ConditionalTagSupport()
Base constructor to initialize local state. As with TagSupport, subclasses should not implement constructors with arguments, and no-argument constructors implemented by subclasses must call the superclass constructor.

Method Details

condition

protected boolean condition()
            throws JspTagException
Subclasses implement this method to compute the boolean result of the conditional action. This method is invoked once per tag invocation by doStartTag().

Returns:
a boolean representing the condition that a particular subclass uses to drive its conditional logic.


doStartTag

public int doStartTag()
            throws JspException
Includes its body if condition() evaluates to true.


release

public void release()
Releases any resources this ConditionalTagSupport may have (or inherit).


setScope

public void setScope(String scope)
Sets the 'scope' attribute.

Parameters:
scope - Scope of the 'var' attribute


setVar

public void setVar(String var)
Sets the 'var' attribute.

Parameters:
var - Name of the exported scoped variable storing the result of condition().


Copyright 2003 Sun Microsystems, Inc. All Rights Reserved.