Using xsi:type

If you have elements in your XML file whose type is a complex type, xsi:type support in the XML editor lets you choose between the complex type and any other complex types derived from it.

1. Create an XML schema and create a complex type for it called Address.
2. Add some basic elements to Address, such as streetName and city.
3. Derive (by extension) two new complex types from Address: USAddress and UKAddress.
4. Add a new element to USAddress called state, and also a new element to UKAddress called postcode.
5. Create two more elements: billTo and shipTo, as Address types.
6. When you create an XML instance document for an element such as billTo or Address, an xsi:type attribute will automatically be added to it. For example,

   <billTo xsi:type="ipo:Address">

   The xsi:type attribute is used to identify derived complex types (as well as complex types that have been derived from).
7. In the Design view of the XML editor, a list will be available, letting you select the appropriate type definition (Address, USAddress, or UKAddress). The guided editing for the content model will reflect the type definition that you choose. For example, if you select USAddress , your billTo element can contain a state element, but it cannot contain a postcode element.