getBuffer() is used to retrieve the data from the Drag-and-drop buffer. You have to identify the current MIME type with getSelectedMimeType() before you use getBuffer(). getBuffer() returns a string value and does not need any arguments.
You should remember that drag-and-drop data can be reached only during the ON DROP block execution, therefore, getBuffer()can be used only in this block.
DISPLAY ARRAY pr_arr TO scr_arr.* ...
...
ON DRAG_ENTER(dd)
-- If the MIME type is unavailable, set operation to NULL
CASE
WHEN dd.selectMimeType("text/plain")
WHEN dd.selectMimeType("text/uri-list")
OTHERWISE
CALL dd.setOperation(NULL)
END CASE
...
ON DROP(dd)
-- Select MIME type and retrieve data from buffer
LET s_row = dd.getLocationRow()
CALL DIALOG.dropped_row("scr_arr", s_row)
IF dn.getSelectMimeType() == "text/plain" THEN
LET pr_arr[s_row].dragegdtext = dd.getBuffer()
END IF
...
END DISPLAY