Very Computer

I have a field that is a drop down data window.  When the window initially
comes up there is no selection and the field is null(There is no entry in the
DB table for the NULL record).  I would like to put a button on the window that
allows me to reset the field back to the state it was when the window came up
(i.e. no selection visable and field is blank).

Does any one have any ideas on how this can be done ?
--
Buddy Mcalister, Sr. Consultant Engineer
Arthur D. Little, Inc
5300 International Blvd N. Charleston, S.C. 29419

Datawindowchild dwc
dw_1.GetChild ("dddwname",dwc)
dwc.InsertRow(1)

Inserts a blank row at row 1....

Peter Bech Lund,
Developer at DAC-DATA, Denmark

Insert an extra row into the DDDW (after the initial retrieve), don't set the "value" column of
the drop-down (that is, leave it NULL).

DATAWINDOWCHILD ldwc_temp
LONG ll_row

IF dw_1.GetChild( "dddw_column_name", ldwc_temp ) > 0 THEN

   // Insert a row at position 1
   ll_row = ldwc_temp.InsertRow( 1 )

   IF ll_row > 0 THEN
      // Set the non-null columns

      // This assumes that you have a description column in the dddw.
      ldwc_temp.SetItem( ll_row, "description", "(None)" )
   END IF  
END IF

Now, the user can select the "Null" row in the drop-down.

-Allen

Allen Hadden
Systems Engineer
Taratec Development Corporation

If I understand you correctly, you wish to be able reset the value back to a 'blank' state
I assume that you may use this 'NULL' value in an 'Update()' statement.  What I have done
in the past is get the hadle to the dddw by using the GetChild function.  Then I code the
function dwc_child.InsertRow (1) which will insert a blank row before the first row in the
result set.  I have used this technique to allow a user to 'reset' a non-editable dddw back
to its 'NULL' state.  This could easily be coded on the clicked event of a commandbutton.

Greg Pettengill

Hi,

Supposing your column is a string, try the following:

cb_::clicked
        dw_.PostEvent ('ue_reset')

dw_::ue_reset
        string ls_Null;  SetNull (ls_Null)
        This.SetItemString (This.GetRow (), ls_Null)

Bye !

Johan Deryckere
LGTsoft (Belgium)

Allen,

        The problem with your way is the the user is going to insert the
word (Null) in their database if they choose null... not the NULL
value.  In order to insert the NULL you have to delete the data
column from the datawindow referenced by the drop down datawindow.  
Replace this with a calculated column that has the following
evaluation:

if(not isNull(origVal), origVal, '(Null)')

        Now go back to the datawindow that holds the dddw.  Set the edit
style and change the display row to your calc'ed column and leave the
datarow the original column.
        What this does is allows your drop down to display the word null
even though the value there is an actual Null.

Rik Brooks
Owner BYTE, Inc.

http://www.halcyon.com/chigh/crh_rb/rb_main.htm

Actually, I made an assumption (possibly incorrect) that there were two
datawindow columns, one for the value and one for a "description".  The
value column would contain the null value and the description would contain
the string "(None)".

I agree that your solution is better if there is only one column.

Allen

Allen Hadden
Systems Engineer
Taratec Development Corporation