<section role="NotInToc" id="a4j_keepAlive">
   <title>
				&lt;
				a4j:keepAlive
				&gt;
				<emphasis role="since">
         <superscript> available since <emphasis role="version">3.0.0</emphasis>
         </superscript>
      </emphasis>
   </title>
   <section>
                    <sectioninfo>
                              <keywordset>
                                        <keyword>a4j:keepAlive</keyword>
                              </keywordset>
                    </sectioninfo>

                    <title>Description</title>
                    <para>The <emphasis role="bold">
                                        <property>&lt;a4j:keepAlive&gt;</property>
                              </emphasis> tag allows to keep a state of a bean between
                              requests.</para>

          </section>
   <section>
                    <title>Details of Usage</title>
                    <para>
                          If a managed bean is declared with <property>request</property> scope in the configuration file with the help of <emphasis role="bold">
            <property>&lt;managed-bean-scope&gt;</property>
         </emphasis> tag then the life-time of this bean instance is valid only for the current request. Any attempts to make a reference to the bean instance after the request end will throw in Illegal Argument Exception by the server. 
                          To avoid these kinds of Exceptions component <emphasis role="bold">
            <property>&lt;a4j:keepAlive&gt;</property>
         </emphasis> is used to maintain the state of the whole bean object among subsequent request.
                    </para>

                    <para>
                              <emphasis role="bold">Example:</emphasis>
                    </para>

                    <programlisting role="XML"><![CDATA[<a4j:keepAlive beanName = "#{myClass.testBean}"/>]]></programlisting>

                    <para> The <emphasis>
            <property>"beanName"</property>
         </emphasis> attribute defines the request scope bean name you'd like to re-use. Note that this attribute must point to a legal JSF EL expression which resolves to a managed mean instance.
                              For example for the above code the class definition may look like this one:
                    </para>
                <programlisting role="JAVA"><![CDATA[class MyClass{
	...
	private TestBean testBean;
	// Getters and Setters for testBean.
	...
}
]]></programlisting>
                    
                <para>
                      The <emphasis>
            <property>"ajaxOnly"</property>
         </emphasis> attribute declares whether the value of the bean should be available during a non-Ajax request. 
                      If the value of this attribute is "true" a request scope bean keeps the same value during Ajax requests from the given page. 
                      If a non-Ajax request is sent from this page the bean is re-created as a regular request scope bean.
                </para>
          </section>
   <section>
      <title>Reference Data</title>
      <para>
         <ulink url="&tlddoc;a4j/keepAlive.html">Table of 
							&lt;a4j:keepAlive&gt; 
							 attributes</ulink>.
						</para>
      <table>
                    <title>Component Identification Parameters </title>
                    <tgroup cols="2">
                              <thead>
                                        <row>
                                                  <entry>Name</entry>
                                                  <entry>Value</entry>
                                        </row>
                              </thead>
                              <tbody>
                                        <row>
                                                  <entry>component-type</entry>
                                                  <entry>org.ajax4jsf.components.KeepAlive</entry>
                                        </row>
                                        <row>
                                                  <entry>component-family</entry>
                                                  <entry>org.ajax4jsf.components.AjaxKeepAlive</entry>
                                        </row>
                                        <row>
                                                  <entry>component-class</entry>
                                                  <entry>org.ajax4jsf.components.AjaxKeepAlive</entry>
                                        </row>
                              </tbody>
                    </tgroup>
          </table>
   </section>
   <section>
                    <title>Relevant Resources Links</title>
                <para>
                      Visit <ulink url="http://livedemo.exadel.com/richfaces-demo/richfaces/keepAlive.jsf?c=keepAlive">KeepAlive page</ulink> at RichFaces Livedemo for examples of component usage and their sources.
                </para>
                
                <para>
                      Search the <ulink url="http://www.jboss.org/index.html?module=bb&amp;op=viewforum&amp;f=261">RichFaces Users forum</ulink> for some additional information about usage of component.
                </para>
          </section>
</section>
