struts-logic.html

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          </td>
</tr>
</table>
</div>
<p>
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<h3 id="present">
<strong>present</strong> - 
    Generate the nested body content of this tag if the specified
    value is present in this request.
    </h3>
<div class="indent">
    <p>Depending on which attribute is specified, this tag checks the
    current request, and evaluates the nested body content of this tag
    only if the specified value <strong>is</strong> present.  Only one
    of the attributes may be used in one occurrence of this tag, unless
    you use the <code>property</code> attribute, in which case the
    <code>name</code> attribute is also required.</p>
    <table class="tag-attributes">
<thead>
<tr>
<th class="attribute">Attribute Name</th>
<th>Description</th>
</tr>
</thead>
<tr class="evenRow">
<td align="center">cookie</td>
<td>
      <p>Checks for the existence of a cookie with the specified name.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">header</td>
<td>
      <p>Checks for the existence of an HTTP header with the specified
      name.  The name match is performed in a case insensitive manner.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">name</td>
<td>
      <p>Checks for the existence of a JSP bean, in any scope, with the
      specified name.  If <code>property</code> is also specified, checks
      for a non-null property value for the specified property.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">parameter</td>
<td>
      <p>Checks for the existence of at least one occurrence of the
      specified request parameter on this request, even if the parameter
      value is a zero-length string.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">property</td>
<td>
      <p>Checks for the existence of a non-null property value, returned
      by a property getter method on the JSP bean (in any scope) that is
      specified by the <code>name</code> attribute.  Property references
      can be simple, nested, and/or indexed.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">role</td>
<td>
      <p>Checks whether the currently authenticated user (if any) has been
      associated with any of the specified security roles. Use a comma-delimited
      list to check for multiple roles. Example:
      <code>&lt;logic:present role="role1,role2,role3"&gt;
                code.....
            &lt;/logic:present&gt;</code>
</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">scope</td>
<td>
      <p>The bean scope within which to search for the bean named by the
      <code>name</code> property, or "any scope" if not specified.</p>
      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">user</td>
<td>
      <p>Checks whether the currently authenticated user principal has the
      specified name.</p>
      
            [RT Expr]
          </td>
</tr>
</table>
</div>
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<h3 id="redirect">
<strong>redirect</strong> - Render an HTTP Redirect</h3>
<div class="indent">

                <p>Performs an <code>HttpServletResponse.sendRedirect()</code>
                call to the hyperlink specified by the attributes to this
                tag.  URL rewriting will be applied automatically, to
                maintain session state in the absence of cookies.</p>

                <p>The base URL for this redirect 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.
                    </li>
                <li>
<em>page</em> - Use the value of this attribute as an
                    module-relative URI, and generate a server-relative
                    URI by including the context path.</li>
                </ul>

                <p>Normally, the redirect you specify with one of the
                attributes described in the previous paragraph will be left
                unchanged (other than URL rewriting if necessary).  However,
                there are two ways you can append one or more dynamically
                defined query parameters to the hyperlink -- specify a single
                parameter with the <code>paramId</code> attribute (and its
                associated attributes to select the value), or specify the
                <code>name</code> (and optional <code>property</code>)
                attributes to select a <code>java.util.Map</code> bean that
                contains one or more parameter ids and corresponding values.
                </p>

                <p>To specify a single parameter, use the <code>paramId</code>
                attribute to define the name of the request parameter to be
                submitted.  To specify the corresponding value, use one of the
                following approaches:</p>
                <ul>
                <li>
<em>Specify only the <code>paramName</code> attribute</em>
                    - The named JSP bean (optionally scoped by the value of the
                    <code>paramScope</code> attribute) must identify a value
                    that can be converted to a String.</li>
                <li>
<em>Specify both the <code>paramName</code> and
                    <code>paramProperty</code> attributes</em> - The specified
                    property getter method will be called on the JSP bean
                    identified by the <code>paramName</code> (and optional
                    <code>paramScope</code>) attributes, in order to select
                    a value that can be converted to a String.</li>
                </ul>

                <p>If you prefer to specify a <code>java.util.Map</code> that
                contains all of the request parameters to be added to the
                hyperlink, use one of the following techniques:</p>
                <ul>
                <li>
<em>Specify only the <code>name</code> attribute</em> -
                    The named JSP bean (optionally scoped by the value of
                    the <code>scope</code> attribute) must identify a
                    <code>java.util.Map</code> containing the parameters.</li>
                <li>
<em>Specify both <code>name</code> and
                    <code>property</code> attributes</em> - The specified
                    property getter method will be called on the bean
                    identified by the <code>name</code> (and optional
                    <code>scope</code>) attributes, in order to return the
                    <code>java.util.Map</code> containing the parameters.</li>
                </ul>

                <p>As the <code>Map</code> is processed, the keys are assumed
                to be the names of query parameters to be appended to the
                hyperlink.  The value associated with each key must be either
                a String or a String array representing the parameter value(s).
                If a String array is specified, more than one value for the
                same query parameter name will be created.</p>
                <table class="tag-attributes">
<thead>
<tr>
<th class="attribute">Attribute Name</th>
<th>Description</th>
</tr>
</thead>
<tr class="evenRow">
<td align="center">action</td>
<td>
                          <p>Logical name of a global <code>Action</code> that
                          contains the actual content-relative URI of the destination
                          of this transfer.  This hyperlink may be dynamically
                          modified by the inclusion of query parameters, as described
                          in the tag description.  You <strong>must</strong> specify
                          exactly one of the <code>action</code> attribute, the
                          <code>forward</code> attribute, the
                          <code>href</code> attribute,
                          or the <code>page</code> attribute.</p>
                      
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">anchor</td>
<td>
                  <p>Optional anchor tag ("#xxx") to be added to the generated
                  hyperlink.  Specify this value <strong>without</strong> any
                  "#" character.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">forward</td>
<td>
                  <p>Logical name of a global <code>ActionForward</code> that
                  contains the actual content-relative URI of the destination
                  of this redirect.  This URI may be dynamically
                  modified by the inclusion of query parameters, as described
                  in the tag description.  You <strong>must</strong> specify
                  exactly one of the <code>forward</code> attribute, the
                  <code>href</code> attribute, the <code>linkName</code>
                  attribute, or the <code>page</code> attribute.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">href</td>
<td>
                  <p>The URL to which this redirect will transfer control.
                  This URL may be dynamically modified
                  by the inclusion of query parameters, as described in the
                  tag description.  You <strong>must</strong> specify
                  exactly one of the <code>forward</code> attribute, the
                  <code>href</code> attribute, the <code>linkName</code>
                  attribute, or the <code>page</code> attribute.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">name</td>
<td>
                  <p>The name of a JSP bean that contains a <code>Map</code>
                  representing the query parameters (if <code>property</code>
                  is not specified), or a JSP bean whose property getter is
                  called to return a <code>Map</code> (if <code>property</code>
                  is specified).</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">page</td>
<td>
                  <p>The context-relative path (beginning with a "/"
                  character) to which this hyperlink will transfer control
                  if activated.  This hyperlink may be dynamically modified
                  by the inclusion of query parameters, as described in the
                  tag description.  You <strong>must</strong> specify exactly
                  one of the <code>forward</code> attribute, the
                  <code>href</code> attribute, the <code>linkName</code>
                  attribute, or the <code>page</code> attribute.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">paramId</td>
<td>
                  <p>The name of the request parameter that will be dynamically
                  added to the generated hyperlink.  The corresponding value is
                  defined by the <code>paramName</code> and (optional)
                  <code>paramProperty</code> attributes, optionally scoped by
                  the <code>paramScope</code> attribute</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">paramName</td>
<td>
                  <p>The name of a JSP bean that is a String containing the
                  value for the request parameter named by <code>paramId</code>
                  (if <code>paramProperty</code> is not specified), or a JSP
                  bean whose property getter is called to return a String
                  (if <code>paramProperty</code> is specified).  The JSP bean
                  is constrained to the bean scope specified by the
                  <code>paramScope</code> property, if it is specified.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">paramProperty</td>
<td>
                  <p>The name of a property of the bean specified by the
                  <code>paramName</code> attribute, whose return value must
                  be a String containing the value of the request parameter
                  (named by the <code>paramId</code> attribute) that will be
                  dynamically added to this hyperlink.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">paramScope</td>
<td>
                  <p>The scope within which to search for the bean specified
                  by the <code>paramName</code> attribute.  If not specified,
                  all scopes are searched.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">property</td>
<td>
                  <p>The name of a property of the bean specified by the
                  <code>name</code> attribute, whose return value must be
                  a <code>java.util.Map</code> containing the query parameters
                  to be added to the hyperlink.  You <strong>must</strong>
                  specify the <code>name</code> attribute if you specify
                  this attribute.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">scope</td>
<td>
                  <p>The scope within which to search for the bean specified
                  by the <code>name</code> attribute.  If not specified, all
                  scopes are searched.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="evenRow">
<td align="center">transaction</td>
<td>
                    <p>Set to <code>true</code> if you want the current
                    transaction control token included in the generated
                    URL for this redirect.</p>
                  
            [RT Expr]
          </td>
</tr>
<tr class="oddRow">
<td align="center">useLocalEncoding</td>
<td>
              <p>If set to <code>true</code>, LocalCharacterEncoding will be
              used, that is, the characterEncoding set to the HttpServletResponse,
              as prefered character encoding rather than UTF-8, when
              URLEncoding is done on parameters of the URL.</p>
              
            [RT Expr]
          </td>
</tr>
</table>
</div>
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