org.apache.taglibs.standard.tag.common.xml

Class ForEachTag

java.lang.Object

javax.servlet.jsp.tagext.TagSupport

javax.servlet.jsp.jstl.core.LoopTagSupport

org.apache.taglibs.standard.tag.common.xml.ForEachTag

All Implemented Interfaces:

Serializable, LoopTag, IterationTag, JspTag, Tag, TryCatchFinally

public class ForEachTag
extends LoopTagSupport

Implementation of <x:forEach> tag using low-level Xalan API.

Author:

Shawn Bayern

See Also:

LoopTagSupport, Serialized Form

Field Summary

Fields inherited from class javax.servlet.jsp.jstl.core.LoopTagSupport

begin, beginSpecified, deferredExpression, end, endSpecified, itemId, statusId, step, stepSpecified

Fields inherited from class javax.servlet.jsp.tagext.TagSupport

id, pageContext

Fields inherited from interface javax.servlet.jsp.tagext.IterationTag

EVAL_BODY_AGAIN

Fields inherited from interface javax.servlet.jsp.tagext.Tag

EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE

Constructor Summary

Constructors

Constructor and Description
ForEachTag()

Method Summary

Methods

Modifier and Type	Method and Description
int	doAfterBody() Continues the iteration when appropriate -- that is, if we (a) have more items and (b) don't run over our 'end' (given our 'step').
void	doFinally() Removes any attributes that this LoopTagSupport set.
protected boolean	hasNext() Returns information concerning the availability of more items over which to iterate.
protected Object	next() Returns the next object over which the tag should iterate.
protected void	prepare() Prepares for a single tag invocation.
void	release() Releases any resources this LoopTagSupport may have (or inherit).
void	setBegin(int begin)
void	setEnd(int end)
void	setSelect(String select)
void	setStep(int step)

Methods inherited from class javax.servlet.jsp.jstl.core.LoopTagSupport

doCatch, doStartTag, getCurrent, getDelims, getLoopStatus, setVar, setVarStatus, validateBegin, validateEnd, validateStep

Methods inherited from class javax.servlet.jsp.tagext.TagSupport

doEndTag, findAncestorWithClass, getId, getParent, getValue, getValues, removeValue, setId, setPageContext, setParent, setValue

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface javax.servlet.jsp.tagext.Tag

doEndTag, getParent, setPageContext, setParent

Constructor Detail

ForEachTag

public ForEachTag()

Method Detail

release

public void release()

Description copied from class: LoopTagSupport

Releases any resources this LoopTagSupport may have (or inherit).

Specified by:

release in interface Tag

Overrides:

release in class LoopTagSupport

See Also:

Tag.release()

prepare

protected void prepare()
                throws JspTagException

Description copied from class: LoopTagSupport

Prepares for a single tag invocation. Specifically, allows subclasses to prepare for calls to hasNext() and next(). Subclasses can assume that prepare() will be called once for each invocation of doStartTag() in the superclass.

Specified by:

prepare in class LoopTagSupport

Throws:

JspTagException

hasNext

protected boolean hasNext()
                   throws JspTagException

Description copied from class: LoopTagSupport

Returns information concerning the availability of more items over which to iterate. This method must be provided by concrete subclasses of LoopTagSupport to assist the iterative logic provided by the supporting base class.

See next for more information about the purpose and expectations behind this tag.

Specified by:

hasNext in class LoopTagSupport

Returns:

true if there is at least one more item to iterate over, false otherwise

Throws:

JspTagException

See Also:

LoopTagSupport.next()

next

protected Object next()
               throws JspTagException

Description copied from class: LoopTagSupport

Returns the next object over which the tag should iterate. This method must be provided by concrete subclasses of LoopTagSupport to inform the base logic about what objects it should iterate over.

It is expected that this method will generally be backed by an Iterator, but this will not always be the case. In particular, if retrieving the next object raises the possibility of an exception being thrown, this method allows that exception to propagate back to the JSP container as a JspTagException; a standalone Iterator would not be able to do this. (This explains why LoopTagSupport does not simply call for an Iterator from its subtags.)

Specified by:

next in class LoopTagSupport

Returns:

the java.lang.Object to use in the next round of iteration

Throws:

JspTagException - for other, unexpected exceptions

doAfterBody

public int doAfterBody()
                throws JspException

Description copied from class: LoopTagSupport

Continues the iteration when appropriate -- that is, if we (a) have more items and (b) don't run over our 'end' (given our 'step').

Specified by:

doAfterBody in interface IterationTag

Overrides:

doAfterBody in class LoopTagSupport

Returns:

SKIP_BODY

Throws:

JspException - if an error occurs while processing this tag

See Also:

IterationTag.doAfterBody()

doFinally

public void doFinally()

Description copied from class: LoopTagSupport

Removes any attributes that this LoopTagSupport set.

These attributes are intended to support scripting variables with NESTED scope, so we don't want to pollute attribute space by leaving them lying around.

Specified by:

doFinally in interface TryCatchFinally

Overrides:

doFinally in class LoopTagSupport

setSelect

public void setSelect(String select)

setBegin

public void setBegin(int begin)
              throws JspTagException

Throws:

JspTagException

setEnd

public void setEnd(int end)
            throws JspTagException

Throws:

JspTagException

setStep

public void setStep(int step)
             throws JspTagException

Throws:

JspTagException