Boxed Component s in Release 7.0, EhP2
Structures or classes often have further structures as components
which are not used every time a program is executed. This can lead to
unnecessary memory usage, especially if these structures are
instantiated multiple times. Examples are structures with substructures
as a row type from internal tables or structures in classes that are
frequently instantiated. To avoid unnecessary memory usage without this
having to be programmed by ABAP developers,
static boxes were introduced as a preliminary form of
boxed component s in Release
7.0 ( EhP2 ). Like strings and internal tables, these are based on
an implicit referencing and support
initial value sharing .
1 Structured types with static boxes
2 Attributes of classes as static boxes
3 Enhancements to RTTS for static boxes
ABAP_MODIFICATION_1 Structured types with static boxes
Within a structure definition using TYPES
BEGIN OF , the BOXED addition of
TYPES can be used to create a substructure as a static box.
ABAP_MODIFICATION_2 Attributes of classes as static boxes
Within a class declaration, the BOXED
addition of DATA can be used to create a structured attribute as
a static box.
ABAP_MODIFICATION_3 Enhancements to RTTS for static boxes
The class CL_ABAP_TYPEDESCR
contains the new constant TYPEKIND_BREF for static boxes. The
value of these constants is specified as the type of a static box in the
component table COMPONENTS of the class
CL_ABAP_STRUCTDESCR . The return
code of the method GET_COMPONENTS of the class
CL_ABAP_STRUCTDESCR contains
boxed component s and reference variables as type description objects
of the class CL_ABAP_REFDESCR . The
method GET_REFERENCED_TYPE of this class gets a type description
object for the substructure. A type description object of the class
CL_ABAP_REFDESCR , which describes a boxed component , cannot be
used in the statements CREATE DATA or
ASSIGN CASTING .
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved