Summary of Dialog Programming Features 

The ABAP programmer is provided with two mechanisms for controlling the interaction between ABAP program and online user. Your program needs some of the features provided, but may not need all. Note that you must never use both mechanisms together in a program.

The two mechanisms are as follows:

In calls to graphics function modules, dialog parameters used to be used to tell the function module to wait for and receive user input. The waiting function module intercepts messages stored in a queue, regardless of their origin, and sets the values of all export parameters. Thus, it only makes sense to ask one function module at a time to wait for input.

For compatibility with older ABAP programs, the non-utility graphics functions can still be used to return their own export parameters. (This requires using the RWNID and M_TYP parameter, and more values for STAT parameter.) This interface is still available, but is not recommended for developing new programs.

For new programs, you should use this mechanism only.

After calling a graphics function module, you must also call GRAPH_RECEIVE, which will wait for messages. ("Waiting for user input" in the section Controlling the Interaction Using Parameters and Utility Function Modules explains why.)

Every ABAP program that responds to user input (as reported by GRAPH_RECEIVE) must call the GET_xxxx_PARAM function for the corresponding graphics program.

The normal graphics functions offer many export parameters that have no meaningful values until activated by calling the utility GET_xxxx_PARAM. In essence, the normal graphics functions have only importing and table parameters, and the GET_xxxx_PARAM functions only exporting and table parameters.

GET_xxxx_PARAM is a collection of function modules, one for each graphic program. The letters xxxx can stand for: BMAT, BUSG, GANTT, HIER, HPGL, PORT, or STAT.

You can use the following dialog parameters with the function module that calls your graphics program.

You must use the STAT parameter whenever your program will transfer data to a window that is already open.

In general, WINID is necessary whenever your program opens several windows and needs to transfer data to them selectively.

PWDID and SUPER specify how to close windows when your program has several open at a time. Neither of these parameters is ever required, but are mutually exclusive if you do use them.

You need not use the dialog parameters in your application program. However, if you don't, the function modules assume particular default values for them. These default values are the same, regardless of which function module you call.

For a detailed description of parameters and exceptions, see the R/3 system documentation (Tools ® ABAP Workbench, Function library button, or transaction code SE37).