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

Class ForEachTag

  • All Implemented Interfaces:
    java.io.Serializable, LoopTag, javax.servlet.jsp.tagext.IterationTag, javax.servlet.jsp.tagext.JspTag, javax.servlet.jsp.tagext.Tag, javax.servlet.jsp.tagext.TryCatchFinally
    public class ForEachTag
extends LoopTagSupport
    Implementation of <x:forEach> tag using low-level Xalan API.
    See Also:
    LoopTagSupport, Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private org.apache.xpath.XPathContext context  
      private org.apache.xpath.XPath select  

      • 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 Description
      ForEachTag()  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method 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.
      (package private) org.apache.xpath.XPathContext getContext()
      Return the current XPath context to support expression evaluation in nested tags.
      protected boolean hasNext()
      Returns information concerning the availability of more items over which to iterate.
      protected java.lang.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​(java.lang.String select)  
      void setStep​(int step)  

      • 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

    • Field Detail

      • select

        private org.apache.xpath.XPath select

      • context

        private org.apache.xpath.XPathContext context

    • 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 javax.servlet.jsp.tagext.Tag
        Overrides:
        release in class LoopTagSupport

      • prepare

        protected void prepare()
                throws javax.servlet.jsp.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:
        javax.servlet.jsp.JspTagException

      • hasNext

        protected boolean hasNext()
                   throws javax.servlet.jsp.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:
        javax.servlet.jsp.JspTagException
        See Also:
        LoopTagSupport.next()

      • next

        protected java.lang.Object next()
                         throws javax.servlet.jsp.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:
        javax.servlet.jsp.JspTagException - for other, unexpected exceptions

      • doAfterBody

        public int doAfterBody()
                throws javax.servlet.jsp.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 javax.servlet.jsp.tagext.IterationTag
        Overrides:
        doAfterBody in class LoopTagSupport
        Throws:
        javax.servlet.jsp.JspException

      • 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 javax.servlet.jsp.tagext.TryCatchFinally
        Overrides:
        doFinally in class LoopTagSupport

      • setSelect

        public void setSelect​(java.lang.String select)

      • setBegin

        public void setBegin​(int begin)
              throws javax.servlet.jsp.JspTagException
        Throws:
        javax.servlet.jsp.JspTagException

      • setEnd

        public void setEnd​(int end)
            throws javax.servlet.jsp.JspTagException
        Throws:
        javax.servlet.jsp.JspTagException

      • setStep

        public void setStep​(int step)
             throws javax.servlet.jsp.JspTagException
        Throws:
        javax.servlet.jsp.JspTagException

      • getContext

        org.apache.xpath.XPathContext getContext()
        Return the current XPath context to support expression evaluation in nested tags.
        Returns:
        the current XPath context