<?xml version="1.0"?>
<document url="struts-bean-el.html">

<properties>
  <author>Craig R. McClanahan</author>
  <author>David M. Karr</author>
  <title>The Struts Framework Project - JSTL Integration - Bean Tags</title>
</properties>

<body>


<taglib>

  <tlibversion>1.2</tlibversion>
  <jspversion>1.1</jspversion>
  <shortname>bean</shortname>
  <display-name>Struts Bean Tags</display-name>
  <uri>http://struts.apache.org/tags-bean-el</uri>
  <info>
  <p>This tag library contains tags useful in accessing beans and their
  properties, as well as defining new beans (based on these accesses)
  that are accessible to the remainder of the page via scripting variables
  and page scope attributes.  Convenient mechanisms to create new beans
  based on the value of request cookies, headers, and parameters are also
  provided.</p>

  <p>Many of the tags in this tag library will throw a
  <code>JspException</code> at runtime when they are utilized incorrectly
  (such as when you specify an invalid combination of tag attributes).  JSP
  allows you to declare an "error page" in the <code>&lt;%@ page %&gt;</code>
  directive.  If you wish to process the actual exception that caused the
  problem, it is passed to the error page as a request attribute under key
  <code>org.apache.struts.action.EXCEPTION</code>.</p>

  <p>If you are viewing this page from within the Struts Documentation
  Application (or online at <a href="http://jakarta.apache.org/struts">
  http://jakarta.apache.org/struts</a>), you can learn more about using
  these tags in the
  <a href="api/org/apache/struts/taglib/bean/package-summary.html#package_description">
  Bean Tags Developer's Guide</a>.</p>
  </info>

  <tag>

    <name>include</name>
    <summary>
    Load the response from a dynamic application request and make it available
    as a bean.
    </summary>
    <tagclass>org.apache.strutsel.taglib.bean.ELIncludeTag</tagclass>
    <teiclass>org.apache.struts.taglib.bean.IncludeTei</teiclass>
    <bodycontent>empty</bodycontent>
    <info>
    <p>Perform an internal dispatch to the specified application component
    (or external URL)
    and make the response data from that request available as a scoped variable of
    type <code>String</code>.  This tag has a function similar to that of
    the standard <code>&lt;jsp:include&gt;</code> tag, except that the
    response data is stored in a page scope attribute instead of being
    written to the output stream.  If the current request is part of a
    session, the generated request for the include will also include the
    session identifier (and thus be part of the same session).</p>

    <p>The URL used to access the specified application component is
    calculated based on which of the following attributes you specify
    (you must specify exactly one of them):</p>
    <ul>
    <li><em>forward</em> - Use the value of this attribute as the name
        of a global <code>ActionForward</code> to be looked up, and
        use the module-relative or context-relative URI found there.</li>
    <li><em>href</em> - Use the value of this attribute unchanged (since
        this might link to a resource external to the application, the
        session identifier is <strong>not</strong> included.</li>
    <li><em>page</em> - Use the value of this attribute as an
        module-relative URI to the desired resource.</li>
    </ul>
    </info>

    <p><strong>WARNING</strong> - Accessing resources protected by security
    constraints, or resources under the <code>/WEB-INF</code> subdirectory,
     with this tag is not supported.  Consider using the
    <code>&lt;jsp:include ... flush="false"&gt;</code> tag on a JSP 1.2
    or later container, or the
    <code>&lt;c:import&gt;</code> tag from the JSP Standard Tag Library
    to accomplish this.</p>

    <attribute>
      <name>anchor</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Optional anchor tag ("#xxx") to be added to the generated
      hyperlink.  Specify this value <strong>without</strong> any
      "#" character.</p>
      </info>
    </attribute>

    <attribute>
      <name>forward</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Logical name of a global <code>ActionForward</code> that contains
      the actual content-relative URI of the resource to be included.</p>
      </info>
    </attribute>

    <attribute>
      <name>href</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Absolute URL (including the appropriate protocol prefix such as
      "http:") of the resource to be included.  Because this URL could be
      external to the current web application, the session identifier will
      <strong>not</strong> be included in the request.</p>
      </info>
    </attribute>

    <attribute>
      <name>id</name>
      <required>true</required>
      <rtexprvalue>false</rtexprvalue>
      <info>
      <p>Specifies the name of the scripting variable (and associated page
      scope attribute) that will be made available with the value of the
      specified web application resource.</p>
      </info>
    </attribute>

    <attribute>
      <name>name</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Module-relative name (starting with a '/') of the web application
      resource to be dispatched, and whose response data is to be made
      available as a bean.</p>
      </info>
      <deprecated>
      Use the "page" attribute instead.
      </deprecated>
    </attribute>

    <attribute>
      <name>page</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Module-relative URI (starting with a '/') of the web application
      resource to be included.</p>
      </info>
    </attribute>

    <attribute>
      <name>transaction</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
        <p>Set to <code>true</code> if you want the current
        transaction control token included in the generated
        URL for this include.</p>
      </info>
    </attribute>

  </tag>


  <tag>

    <name>message</name>
    <summary>
    Render an internationalized message string to the response.
    </summary>
    <tagclass>org.apache.strutsel.taglib.bean.ELMessageTag</tagclass>
    <bodycontent>empty</bodycontent>
    <info>
    <p>Retrieves an internationalized message for the specified locale,
    using the specified message key, and write it to the output stream.
    Up to five parametric replacements (such as "{0}") may be specified.</p>

    <p>The message key may be specified directly, using the <code>key</code>
    attribute, or indirectly, using the <code>name</code> and
    <code>property</code> attributes to obtain it from a bean.</p>
    
    <p>
    <strong>JSTL</strong>:  The equivalent JSTL tag is &lt;fmt:message&gt;.  For example,
    <br/>
    <code>
    	&lt;fmt:message key="my.msg.key"&gt;
    	  &lt;fmt:param value="replacement text"/&gt;
    	&lt;/fmt:message&gt;
    </code>
    </p>
    </info>

    <attribute>
      <name>arg0</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>First parametric replacement value, if any.</p>
      </info>
    </attribute>

    <attribute>
      <name>arg1</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Second parametric replacement value, if any.</p>
      </info>
    </attribute>

    <attribute>
      <name>arg2</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Third parametric replacement value, if any.</p>
      </info>
    </attribute>

    <attribute>
      <name>arg3</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Fourth parametric replacement value, if any.</p>
      </info>
    </attribute>

    <attribute>
      <name>arg4</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Fifth parametric replacement value, if any.</p>
      </info>
    </attribute>

    <attribute>
      <name>bundle</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>The name of the application scope bean under which the
      <code>MessageResources</code> object containing our messages
      is stored.</p>
      </info>
      <default>Globals.MESSAGES_KEY</default>
    </attribute>

    <attribute>
      <name>key</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>The message key of the requested message, which must have
      a corresponding value in the message resources. If not specified,
      the key is obtained from the <code>name</code> and
      <code>property</code> attributes.</p>
      </info>
    </attribute>

    <attribute>
      <name>locale</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>The name of the session scope bean under which our currently
      selected <code>Locale</code> object is stored.</p>
      </info>
      <default>Globals.LOCALE_KEY</default>
    </attribute>

    <attribute>
      <name>name</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Specifies the attribute name of the bean whose property is accessed
      to retrieve the value specified by <code>property</code> (if
      specified).  If <code>property</code> is not specified, the value of
      this bean itself will be used as the message resource key.</p>
      </info>
    </attribute>

    <attribute>
      <name>property</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Specifies the name of the property to be accessed on the bean
      specified by <code>name</code>.  This value may be a simple, indexed,
      or nested property reference expression.  If not specified, the value
      of the bean identified by <code>name</code> will itself be used as the
      message resource key.</p>
      </info>
    </attribute>

    <attribute>
      <name>scope</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Specifies the variable scope searched to retrieve the bean specified
      by <code>name</code>.  If not specified, the default rules applied by
      <code>PageContext.findAttribute()</code> are applied.</p>
      </info>
    </attribute>

  </tag>


  <tag>

    <name>page</name>
    <summary>
    Expose a specified item from the page context as a bean.
    </summary>
    <tagclass>org.apache.strutsel.taglib.bean.ELPageTag</tagclass>
    <bodycontent>empty</bodycontent>
    <info>
    <p>Retrieve the value of the specified item from the page context
    for this page, and define it as a scripting variable, and a page scope
    attribute accessible to the remainder of the current page.</p>

    <p>If a problem occurs while retrieving the specified configuration
    object, a request time exception will be thrown.</p>
    </info>

    <attribute>
      <name>id</name>
      <required>true</required>
      <rtexprvalue>false</rtexprvalue>
      <info>
      <p>Specifies the name of the scripting variable (and associated
      page scope attribute) that will be made available with the value of
      the specified page context property.</p>
      </info>
    </attribute>

    <attribute>
      <name>property</name>
      <required>true</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Name of the property from our page context to be retrieved and
      exposed.  Must be one of <code>application</code>, <code>config</code>,
      <code>request</code>, <code>response</code>, or <code>session</code>.
      </p>
      </info>
    </attribute>

  </tag>


  <tag>

    <name>resource</name>
    <summary>
    Load a web application resource and make it available as a bean.
    </summary>
    <tagclass>org.apache.strutsel.taglib.bean.ELResourceTag</tagclass>
    <teiclass>org.apache.struts.taglib.bean.ResourceTei</teiclass>
    <bodycontent>empty</bodycontent>
    <info>
    <p>Retrieve the value of the specified web application resource, and make
    it available as either a <code>InputStream</code> or a <code>String</code>,
    depending on the value of the <code>input</code> attribute.</p>

    <p>If a problem occurs while retrieving the specified resource, a
    request time exception will be thrown.</p>
    </info>

    <attribute>
      <name>id</name>
      <required>true</required>
      <rtexprvalue>false</rtexprvalue>
      <info>
      <p>Specifies the name of the scripting variable (and associated page
      scope attribute) that will be made available with the value of the
      specified web application resource.</p>
      </info>
    </attribute>

    <attribute>
      <name>input</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>If any arbitrary value for this attribute is specified, the resource
      will be made available as an <code>InputStream</code>.  If this
      attribute is not specified, the resource will be made available
      as a <code>String</code>.</p>
      </info>
    </attribute>

    <attribute>
      <name>name</name>
      <required>true</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Module-relative name (starting with a '/') of the web application
      resource to be loaded and made available.</p>
      </info>
    </attribute>

  </tag>


  <tag>

    <name>size</name>
    <summary>
    Define a bean containing the number of elements in a Collection or Map.
    </summary>
    <tagclass>org.apache.strutsel.taglib.bean.ELSizeTag</tagclass>
    <teiclass>org.apache.struts.taglib.bean.SizeTei</teiclass>
    <bodycontent>empty</bodycontent>
    <info>
    <p>Given a reference to an array, Collection or Map, creates a new bean, of
    type <code>java.lang.Integer</code>, whose value is the number of elements
    in that collection.  You can specify the collection to be counted in any
    one of the following ways:</p>
    <ul>
    <li>As a runtime expression specified as the value of the
        <code>collection</code> attribute.</li>
    <li>As a JSP bean specified by the <code>name</code> attribute.</li>
    <li>As the property, specified by the <code>property</code> attribute,
        of the JSP bean specified by the <code>name</code> attribute.</li>
    </ul>
    </info>

    <attribute>
      <name>collection</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>A runtime expression that evaluates to an array, a Collection, or
      a Map.</p>
      </info>
    </attribute>

    <attribute>
      <name>id</name>
      <required>true</required>
      <rtexprvalue>false</rtexprvalue>
      <info>
      <p>The name of a page scope JSP bean, of type
      <code>java.lang.Integer</code>, that will be created to contain the
      size of the underlying collection being counted.</p>
      </info>
    </attribute>

    <attribute>
      <name>name</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>The name of the JSP bean (optionally constrained to the scope
      specified by the <code>scope</code> attribute) that contains the
      collection to be counted (if <code>property</code> is not specified),
      or whose property getter is called to return the collection to be
      counted (if <code>property</code> is specified.</p>
      </info>
    </attribute>

    <attribute>
      <name>property</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>The name of the property, of the bean specified by the
      <code>name</code> attribute, whose getter method will return the
      collection to be counted.</p>
      </info>
    </attribute>

    <attribute>
      <name>scope</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>The bean scope within which to search for the JSP bean specified
      by the <code>name</code> attribute.  If not specified, the available
      scopes are searched in ascending sequence.</p>
      </info>
    </attribute>

  </tag>


  <tag>

    <name>struts</name>
    <summary>
    Expose a named Struts internal configuration object as a bean.
    </summary>
    <tagclass>org.apache.strutsel.taglib.bean.ELStrutsTag</tagclass>
    <teiclass>org.apache.struts.taglib.bean.StrutsTei</teiclass>
    <bodycontent>empty</bodycontent>
    <info>
    <p>Retrieve the value of the specified Struts internal configuration
    object, and define it as a scripting variable and as a page scope
    attribute accessible to the remainder of the current page.  You must
    specify exactly one of the <code>formBean</code>, <code>forward</code>,
    and <code>mapping</code> attributes to select the configuration object
    to be exposed.</p>

    <p>If a problem occurs while retrieving the specified configuration
    object, a request time exception will be thrown.</p>
    </info>

    <attribute>
      <name>id</name>
      <required>true</required>
      <rtexprvalue>false</rtexprvalue>
      <info>
      <p>Specifies the name of the scripting variable (and associated
      page scope attribute) that will be made available with the value of
      the specified Struts internal configuration object.</p>
      </info>
    </attribute>

    <attribute>
      <name>formBean</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Specifies the name of the Struts <code>ActionFormBean</code>
      definition object to be exposed.</p>
      </info>
    </attribute>

    <attribute>
      <name>forward</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Specifies the name of the global Struts <code>ActionForward</code>
      definition object to be exposed.</p>
      </info>
    </attribute>

    <attribute>
      <name>mapping</name>
      <required>false</required>
      <rtexprvalue>true</rtexprvalue>
      <info>
      <p>Specifies the matching path of the Struts <code>ActionMapping</code>
      definition object to be exposed.</p>
      </info>
    </attribute>

  </tag>

</taglib>

</body>

</document>
