Type casting refines the results of a query and allows Rational® Publishing Engine to treat
.xsd schema types as being from a different type, similar to cast operations in
programming languages. A type is not assigned to schema elements that can have more than one valid
type. You define the types for these elements with the cast to type feature in
the Data Source View.
About this task
Type casting works as an alternate filter for data source elements. A cast query
filters the results of the regular query to return only the elements that can be cast to the
selected type. After the type is selected, it becomes available in the Data Source
View under the anyType element. Queries built using cast allow
access to all the child elements and attributes of the type cast. The result set returned by a cast
query is identical to the result set returned by a query that is filtered with an equivalent
IsKindOf predicate. The difference between the cast query and filtered query
is that a cast query gives access to the cast type attributes and child elements while the filtered
query does not.
Procedure
- From the Palette view, drag a
Container element
into the template content editor.
- From the Data Source View, drag the ownedMember
class into the container element.
- Optional: Name the container Class
Container for easier reference.
- Click the
Cast to Type icon
to add the Class type cast for the ownedMember.
- Add a
Paragraph element below
the container element.
- From the Data Source View, drag the Name(string)
attribute into the Class Container to add the name of the package.