Assignment Rules for Binding Definitions

Use

Basically, you cannot use an attribute of a BOR object type as a target of a binding row.

Identity and compatibility of data types

Identical data types

A binding definition is possible if the two container elements or expressions have identical data types. The data type is specified using the data type reference of the relevant container element.

Compatible Data Types

Compatible data types A binding definition is also possible if the two container elements or expressions have compatible data types.

Data types expressed by field references are compatible under the following circumstances:

No field is specified for the target element of the assignment, but it is an ABAP Dictionary reference.

Data types expressed by an object reference are compatible under the following circumstances:

The source element references an object type that is a subtype of the object type referenced by the target element (meaning that subtype supertype is allowed).
No object type is specified for the target element of the assignment, but it is an object type reference.

Example

A binding definition from the element _WI_Object_ID (with a data type reference to object type FORMABSENC) in the task container to the element UntypedObject (with an unspecified data type reference to an object type) in the workflow container is allowed.

However, a binding definition from an unspecified element to an element with a specified data type reference is not allowed.