Here is an example rule set with DisplaySubscreen rule attributes:
<?xml version="1.0" encoding="UTF-8"?>
<RuleSet name="Example_DisplaySubscreen"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation=
"http://www.curamsoftware.com/CreoleRulesSchema.xsd">
<Class name="MyProductSummary" extends="DefaultCase"
extendsRuleSet="DefaultProductDecisionDetailsRuleSet">
<!-- Allow the screen to display a list of members for the
case. -->
<Attribute name="householdMembers">
<Annotations>
<Display/>
</Annotations>
<type>
<javaclass name="List">
<ruleclass name="HouseholdMember"/>
</javaclass>
</type>
<derivation>
<specified/>
</derivation>
</Attribute>
<!-- Allow the screen to drill down into more details for each
household member -->
<Attribute name="householdMemberSubscreens">
<Annotations>
<DisplaySubscreen/>
</Annotations>
<type>
<javaclass name="List">
<ruleclass name="HouseholdMemberSubscreen"/>
</javaclass>
</type>
<derivation>
<dynamiclist>
<list>
<reference attribute="householdMembers"/>
</list>
<!-- Create a wrapper HouseholdMemberSubscreen for each
HouseholdMember -->
<listitemexpression>
<create ruleclass="HouseholdMemberSubscreen">
<specify attribute="householdMember">
<current/>
</specify>
</create>
</listitemexpression>
</dynamiclist>
</derivation>
</Attribute>
</Class>
<Class name="HouseholdMember">
<Attribute name="concernRoleID">
<type>
<javaclass name="Number"/>
</type>
<derivation>
<specified/>
</derivation>
</Attribute>
<Attribute name="earnedIncome">
<type>
<javaclass name="Number"/>
</type>
<derivation>
<specified/>
</derivation>
</Attribute>
<Attribute name="unearnedIncome">
<type>
<javaclass name="Number"/>
</type>
<derivation>
<specified/>
</derivation>
</Attribute>
</Class>
<Class name="HouseholdMemberSubscreen"
extends="AbstractCaseSubscreenDisplay"
extendsRuleSet="DefaultProductDecisionDetailsRuleSet">
<!-- The wrapped household member -->
<Attribute name="householdMember">
<type>
<ruleclass name="HouseholdMember"/>
</type>
<derivation>
<specified/>
</derivation>
</Attribute>
<!-- identifier of the business object -->
<Attribute name="businessObjectID">
<type>
<javaclass name="Number"/>
</type>
<derivation>
<reference attribute="concernRoleID">
<reference attribute="householdMember"/>
</reference>
</derivation>
</Attribute>
<!-- Data to display on the subscreen -->
<Attribute name="totalIncome">
<Annotations>
<Display/>
</Annotations>
<type>
<javaclass name="Number"/>
</type>
<derivation>
<arithmetic operation="+">
<reference attribute="earnedIncome">
<reference attribute="householdMember"/>
</reference>
<reference attribute="unearnedIncome">
<reference attribute="householdMember"/>
</reference>
</arithmetic>
</derivation>
</Attribute>
</Class>
</RuleSet>