Options for Using Collection Classes

Within an XML-enabled class, tor each property of type %ListOfDataTypesOpens in a new tab or %ArrayOfDataTypesOpens in a new tab, the collection item is assumed to be a string; this assumption may or may not be suitable for your needs. Similarly, for each property of type %ListOfObjectsOpens in a new tab or %ArrayOfObjectsOpens in a new tab, the collection item type is RegisteredObject, and InterSystems IRIS does not include an XML projection for the type RegisteredObject, so the XML schema is not usable.

In these scenarios, you can do either of the following:

Modify the property definition to have the form List of Classname or Array of Classname, where Classname is a suitable class. If Classname is an object class, XML-enable the class.
Create a custom subclass of the collection class (%ListOfDataTypesOpens in a new tab, %ArrayOfDataTypesOpens in a new tab, %ListOfObjectsOpens in a new tab, %ArrayOfObjectsOpens in a new tab). In the subclass, specify the ELEMENTTYPE class parameter. For example:
```
Class MyApp.MyIntegerCollection Extends %ListOfDataTypes
{
Parameter ELEMENTTYPE="%Library.Integer";

}
```
For ELEMENTTYPE, specify the complete package and class name of the class used in the collection. If you subclass %ListOfDataTypesOpens in a new tab or %ArrayOfDataTypesOpens in a new tab, specify a data type class. Then the type for the collection element is controlled by the XSDTYPE parameter for that class.
If you subclass %ListOfObjectsOpens in a new tab or %ArrayOfObjectsOpens in a new tab, specify an XML-enabled class. For example
```
Class MyApp.MyObjectCollection Extends %ListOfObjects
{
Parameter ELEMENTTYPE="MyApp.SimpleObject";

}
```
Then use your custom collection class in your property definition. For example:
```
Property MyProp as MyApp.MyIntegerCollection;
```