How to Show Theme Fragment Conditionaly

A theme describes what you show and how you show it in your application. It is a set of pages, sections, cells and fragments. It is possible to show some fragment depending on some condition using perspective. A perspective is an attribute of the fragment element. If there is no perspective attribute, the fragment will be shown in all perspective. In a default Nuxeo Platform instance, there is only one perspective named default.

1. First you need to register the perspective with:

   <extension target="org.nuxeo.theme.services.ThemeService"
       point="perspectives">
     <perspective name="myperspective">
       <title>perspective not to be shown all the time</title>
     </perspective>
   </extension>
   
   

   A perspective is just a name.

2. then you add a perspective attribute to your fragment in the theme configuration:

   <!--this shows the fragment only in myperspective perspective.-->
   <fragment perspectives="myperspective" type="generic fragment"/>
   <!--this shows the fragment in myperspective and the default perspective. -->
   <fragment perspectives="myperspective,default" type="generic fragment"/>
   
   

3. Finally, you add your own scheme to the perspective negociator to resolve the perspective:

   <extension target="org.nuxeo.theme.services.ThemeService" point="negotiations">
     <negotiation object="perspective" strategy="web"> <!--strategy is web for webengine and default for jsf-->
       <scheme>
         com.mycompany.mMnegociator  <!--here is you class-->
       </scheme>
     <!--don't forget to add the other perspective negociators -->
   </extension>
   
   

   Your class should implement the Scheme interface. The getOutcome method is passed a WebContext or a FacesContext. If you can't decide which perspective it is, return null, the query will be passed to the next negociator.