13. A system comprising: a computer to: receive a definition of an extension field to be added to a first node of a business object; determine to generate metadata for a data type enhancement object associated with the extension field, the determination being based on a switch framework that indicates which extensions are active or not active in a first client; generate metadata for the data type enhancement object associated with the extension field; and generate an ABAP dictionary proxy object based on the data type enhancement object, wherein the ABAP dictionary proxy object describes the extension field in a sub-structure of a first field of the ABAP dictionary proxy object; wherein a field of the first node of the business object and to which the extension field is to be added is defined by a first data type and a first attribute indicates whether the first data type is dynamically extensible; wherein a field of a second node of the business object is defined by a second data type and a second attribute indicates whether the second data type is dynamically extensible; and wherein the first attribute indicates that the first data type is dynamically extensible; the computer further to: specify that the first attribute is editable; specify that the second attribute is not editable; synchronize a switch setting for the data type enhancement object and a switch setting for a corresponding business object enhancement object; provide a switch setting indicating that a business function is active in the first client; and allow addition of an extension in the first client without requiring that a second client reload all data into a data buffer.
13. A system comprising: a computer to: receive a definition of an extension field to be added to a first node of a business object; determine to generate metadata for a data type enhancement object associated with the extension field, the determination being based on a switch framework that indicates which extensions are active or not active in a first client; generate metadata for the data type enhancement object associated with the extension field; and generate an ABAP dictionary proxy object based on the data type enhancement object, wherein the ABAP dictionary proxy object describes the extension field in a sub-structure of a first field of the ABAP dictionary proxy object; wherein a field of the first node of the business object and to which the extension field is to be added is defined by a first data type and a first attribute indicates whether the first data type is dynamically extensible; wherein a field of a second node of the business object is defined by a second data type and a second attribute indicates whether the second data type is dynamically extensible; and wherein the first attribute indicates that the first data type is dynamically extensible; the computer further to: specify that the first attribute is editable; specify that the second attribute is not editable; synchronize a switch setting for the data type enhancement object and a switch setting for a corresponding business object enhancement object; provide a switch setting indicating that a business function is active in the first client; and allow addition of an extension in the first client without requiring that a second client reload all data into a data buffer. 14. A system according to claim 13 , wherein the switch framework indicates that the extension field is active in the first client; and wherein the determine to generate metadata for a data type enhancement object associated with the extension field comprises: determine to generate the metadata for the data type enhancement object associated with the extension field based on the switch framework indication that the extension field is active in the first client.