What I find a bit cumbersome with the APL Grid is the asymmetry of handling Missing Values. When I retrieve data from cells, that contains nothing, than the contents will be displayed in APL as ConversionErrorValue (i.e. -2147352572). When I write the array back to the grid, the cell contents (which previously contained nothing) is displayed as -2147352572
Here is an example illustrating the problem:
1) open the Grid example (fmDemoGrid_Hnd, fmDemoGrid_Make) of the REL50.w3 Workspace distributed with APL+Win
2) delete a cell in the Annual Sales Page using the <DELETE> key
3) move the selection to the next cell
4) than the contents of the "empty cell" will be displayed as -2147352572
(this will not apply if you delete the cell contents using the backspace key, because the code in fmDemoGrid_Hnd 'onXEditComplete' will reset an empty cell to Zero)
Actually, I'm looking for a way to tell the grid that a specific numeric value (i.e. the ConversionErrorValue or -2147352572) is a Missing Value and should not be displayed.
I have an APL Array where certain cells contain Missing Values, which I encoded with -2147352572. How can I set this array into the grid so that the cells with -2147352572 contain nothing and still are numeric (xValueType=2)?
In our current code, I set the APL array right into the grid and then 'xDeleteCells' all cells containing a missing value (-2147352572) but this is not very convenient when the missing values are scattered around in the grid.