tut_implicitobjects.apt

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                                  Implicit objects created by table
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                                          Fabrizio Giustina
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                                              11-11-2005
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Implicit objects created by table

+-------------------------------------------------------------------+
<display:table name="test" id="testit">
    <display:column property="id" title="ID" />
    <display:column property="name" />
    <display:column title="static value">static</display:column>
    <display:column title="row number (testit_rowNum)"><%=pageContext.getAttribute("testit_rowNum")%></display:column>
    <display:column title="((ListObject)testit).getMoney()">
      <%=((ListObject)pageContext.getAttribute("testit")).getMoney()%>
    </display:column>
</display:table>
+-------------------------------------------------------------------+


   If you add and id attribute the table tag makes the object
   corresponding to the given row available in the page context so you
   could use it inside scriptlet code or some other tag. Another
   implicit object exposed by the table tag is the row number, named
   id_rowNum .

   These objects are saved as attributes in the page scope (you can
   access it using pageContext.getAttribute("id") ). They are also
   defined as nested variables (accessible using <<<\<%=id%\>>>> ), but only if
   the value of the id atribute is not a runtime expression. The
   preferred way for fetching the value is to always use
   pageContext.getAttribute().

   If you do not specify the id attribute no object is added to the
   pageContext by the table tag

   This is a simple snippet which shows the use of the implicit objects
   created by the table tag with JSTL.

+-------------------------------------------------------------------+
  <display table id="row" name="mylist">
    <display:column title="row number" >
      <c:out value="${row_rowNum}"/>
    </display:column>
    <display:column title="name" >
      <c:out value="${row.first_name}"/>
      <c:out value="${row.last_name}"/>
    </display:column>
  </display:table>
+-------------------------------------------------------------------+