1. A computer program product comprising a computer readable storage device having a computer readable program stored thereon, wherein the computer readable program when executed on a computer causes the computer to: provide a data interface between an adapter component and one or more application interface components for a runtime application; establish a cursor that iterates over a first plurality of data objects within a data set of the runtime application and a child cursor that iterates over a second plurality of data objects, wherein each data object in the second plurality of data objects corresponds to a data object in the first plurality of data objects; establish an accessor that provides access to a data element of a data object in the first plurality of data objects and a child accessor that provides access to a corresponding data element of a corresponding data object in the second plurality of data objects; and provide the cursor, the child cursor, and the accessor to the adapter component so that the adapter component accesses data through the one or more application interface components of the runtime application, wherein, in response to the cursor iterating to point to a new data object in the first plurality of data objects, repositioning (1) the accessor to provide access to a data element of the new data object in the first plurality of data objects, (2) the child cursor to point to a new data object in the second plurality of data objects corresponding to the new data object in the first plurality of data objects, and (3) the child accessor to provide access to a corresponding data element of the new data object in the second plurality of data objects.