Objectifs : permettre aux auteurs d' :
- exprimer des contenus ou des ressources alternatives
- exprimer les conditions dans lesquelles chaque alternative doit
être exploitée
<sel:select>
<sel:when sel:expr="screen-width > 400 and available-colors > 4">
<img alt="Many people had to be evacuated." src="imagebig"/>
</sel:when>
<sel:when sel:expr="screen-width > 100 and available-colors > 4">
<img alt="Many people had to be evacuated." src="imagesmall"/>
</sel:when>
<sel:otherwise>
<p>Many people had to be evacuated.</p>
</sel:otherwise>
</sel:select>