A composite key provides a way to identify a data element within a structure of data collections. It is a concatenation of all date element names in the regressive path from the top of the structure down to the desired data element. For example, say you wanted to retrieve the street name of a customer's address. To do this, you would provide a composite key like the following example: customerListData.2.address.street

The toolkit uses the composite key to search the customerListData data element for the data element in the 2 position, which is a customerInfo data element. The toolkit then searches in the customerInfo data element for the address element. Finally, it searches for the street data field in the address data element. The following diagram depicts this search:

The toolkit recognizes the asterisk (*) as a wild card. If the composite key has the wildcard, the toolkit returns the first data element it finds. For example, if the composite key given in the call had been *.address.street, the method would have returned the street inside the IndexedCollection's first customerInfo KeyedCollection. In other words, *.address.street = customerList.0.address.street.