And to include that easily I think the easiest way it to add this javascript fragment in a dedicate javascript file for instance name it myfunc.js

• You create a regular Nuxeo project (not webEngine) with Nuxeo IDE.
• Copy your myfunc.js file into src/main/resources/web/scripts/myfunc.js in your project.
• Add this following contribution in src/main/resources/OSGI-INF/myproject-widget-contrib.xml

Here is the contribution:

 <component name="fr.mycompany.myproject.widget.contrib">
     <!-- to be sure to be deployed AFTER the default configuration to override it-->
     <require>org.nuxeo.theme.nuxeo.default</require>

    <!-- first you declare your javascript resources -->
    <extension target="org.nuxeo.theme.services.ThemeService" point="resources">
      <resource name="myfunc.js">
        <path>scripts/myfunc.js</path>
      </resource>
    </extension>

    <!-- and you override a xhtml fragment present everywhere in default Nuxeo JSF pages
            to append your javascript fragment -->
    <extension target="org.nuxeo.theme.services.ThemeService" point="views">
      <view name="nuxeo5 includes" template-engine="jsf-facelets">
        <resource>myfunc.js</resource>
      </view>
    </extension>

 </component>