The ON FILL BUFFER block is used to fill a page of rows into the dynamic array, based on an offset and a number of rows.

This data block is only used in DISPLAY ARRAY dialog blocks.

The offset can be retrieved with the FGL_DIALOG_GETBUFFERSTART() built-in function and the number of rows to provide is defined by the FGL_DIALOG_GETBUFFERLENGTH() built-in function.

The ON FILL BUFFER block is executed when the runtime system needs data rows to fill the current page of the list dialog. This can happen before a BEFORE DISPLAY of a singular DISPLAY ARRAY, or before the BEFORE DIALOG block of a DIALOG / END DIALOG instruction containing DISPLAY ARRAY sub-dialogs.

For more details about ON FILL BUFFER usage, see Paged mode of DISPLAY ARRAY.