The other place the data web scripts may be extended is via the property decorator extension mechanism.
To add a new property decorator, the baseDecorator bean needs to be extended with the property decorator you wish to use. For example:
<beanid="customPropertyDecorator"parent="baseDecorator"class="org.alfresco.repo.jscript.app.UsernamePropertyDecorator">
<property name="nodeService" ref="nodeService"/>
<property name="personService" ref="PersonService" />
<property name="propertyNames">
<set>
<value>ds:uploader</value>
</set>
</property>
</bean>