1. Sample of UI, which select typical form

XML Sapiens DDC

<sapi version="1.0" xmlns:sapi="http://www.xmlsapiens.org/spec/sapi.dtd">  <sapi:ddc name="menu" title="ddc" ns="site1" category="navigation">  <sapi:author>   <sapi:name>Max Baryshnikov</sapi:name>   <sapi:email>mb@rg.by</sapi:email>   <sapi:url>www.redgraphic.com</sapi:url>  </sapi:author>  <sapi:comments>DDC Sample 1 </sapi:comments>  <sapi:choose>   <sapi:when exp="eq('user.aStatus.value',1)">          <sapi:code>         User <sapi:apply name="user.login.value" /> was authorized       </sapi:code>    </sapi:when>    <sapi:when exp="neq('user.aStatus.value',1)">          <sapi:code>         Nobody is authorized       </sapi:code>    </sapi:when>   </sapi:choose>  </sapi:ddc> </sapi>

Algorithm

2. Sample of UI, which show site menu

XML Sapiens DDC

<sapi version="1.0" xmlns:sapi="http://www.xmlsapiens.org/spec/sapi.dtd">  <sapi:ddc name="menu" title="ddc" ns="site1" category="navigation">  <sapi:author>   <sapi:name>Max Baryshnikov</sapi:name>   <sapi:email>mb@rg.by</sapi:email>   <sapi:url>www.redgraphic.com</sapi:url>  </sapi:author>  <sapi:comments>DDC Sample 2</sapi:comments>  <sapi:choose>   <sapi:when exp="true">     <sapi:for-each select="get_tree()" name="enum">     <sapi:choose>            <sapi:when exp="eq(this.this.currentpage.value,1)">             <sapi:code>             <a class="active" sapi:href="this.this.HREF.value"><sapi:apply name="this.this.TITLE.value" /></a><br />             </sapi:code>             </sapi:when>            <sapi:when exp="neq(this.this.currentpage.value,1)">             <sapi:code>             <a class="inactive" sapi:href="this.this.HREF.value"><sapi:apply name="this.this.TITLE.value" /></a><br />             </sapi:code>             </sapi:when>     </sapi:choose>    </sapi:for-each>   </sapi:when>  </sapi:choose>  </sapi:ddc> </sapi>

Algorithm