source:http://www.architectsap.com/blog/sap/sap-eccabap-enhancement-technique-bdt/
Business data toolset is a new functionality provided by SAP to modify screen i.e. standard screens.BDT is helpful as many times the customization of screens are required in SAP ABAP development.
Modification Available:
If the requirement is to add new fields, shift fields from one tab to another tab, add field groups, create views, and create sections in a screen, BDT helps you to do that.
- Field Group – Field grouping is a way to group list of fields. Fields that co-exists all the time can be grouped into one Field group. Display attributes like hiding fields or making fields optional or mandatory or display only is set at field group level for ease of maintenance. For example, if a transaction has two fields named start date and end date, its likely that these two fields always co-exists i.e. either both of the fields get displayed or both of them hidden but never one field is displayed and other is hidden so these two fields can be created under same field group.
- View – One or more field groups constitute a view. All fields that are displayed and checked together are created as view. For ex, if a view two field groups included, all the fields from the two field groups always get displayed together. One field group can be hidden and another can be displayed (display attribute is configurable at field group level) but if both are displayed, they will be displayed together i.e. you can’t split fields in a view and display some in one screen and another in another screen. Technically a view is nothing but a sub screen and all the fields in the included field groups are added to this sub screen through screen painter.
- Section – One or more views can be grouped into a section. The BDT automatically puts a frame around the section in display. The advantage with having section is views that make sense together can be grouped into one section and they will be displayed together. If at later stage this is not required, the views can be displayed in separate block by just moving the view from the existing section to separate section.
- Screen – One or more sections can be grouped into a screen. Screen is the biggest unit in the screen layout. Each screen will be displayed as a tab in the final transaction.
But not all transactions will be BDT enabled in SAP.For example, Business partner is a BDT enabled transaction in SAP.New custom fields can be created; existing fields can be moved or deleted.
For each BDT enabled transaction a separate area menu will be available.
How to find if transaction has above modification technique available?
One way to know this is by putting a breakpoint in BUS_PBO function module and then execute the transaction. If it stops there, then be sure that it uses BDT.
Second way is: All BDT-enabled applications call function module “BDT_TBZ0A_GET” to find out specifically what, if anything, has been enhanced.
Put a break-point in the function module.
Execute the transaction that needs to be enhanced.
When your break-point is hit, look at the value assigned to variable IV_OBJAP. This is application object.
If the break-point is not hit, chances are that application doesn’t use the BDT.