PRODUCT   :  R:BASE                  VERSION      :  3.1
   From Gail Coverdell, 155 Good Country Road, Kalispell, MT 59901. Gail
   is a science teacher and small business application developer. You can
   reach her at 406-752-4435.
   Often it's convenient to have R:BASE automatically number the tiers
   (lines) in a region.
   When to Use Subnumbers
   Typically, the form looks like TRANFORM in the CONCOMP database with
   one or more autonumber columns such as CUSTID or TRANSID at the top
   part of the form to identify it and a subnumber column such as LINENUM
   or DETAIL# in the form's region to number the tiers (lines).
   Below are examples of items that you might want to number in a region:
     o  Line items in a customer's order
     o  Tasks under a unique objective
     o  To-do list items for a specific date
     o  Chapters under a book name
     o  Symptoms for a patient on a specific visit to the doctor.
   Numbering Automatically
   R:BASE automatically numbers autonumber columns, assigning the next
   number when you move to a new row. But you don't want a subnumber
   column to be an autonumber column because you want subnumbers to start
   over for each new region (group of rows).
   To number subnumbers automatically, use the following technique. But
   first check the "Guidelines and Restrictions" section below to make
   sure your form is a good candidate for automatic subnumbers.
   Creating a Subnumber Form
   Complete the following steps to make an ordinary form region into one
   that automatically numbers its lines (tiers). In order for this to
   work, the table associated with the region must not contain a computed
   The following explanation assumes that the subnumber column is an
   INTEGER named LINENUM. If your subnumber column has some other name,
   change all the occurrences of LINENUM to the correct name. This
   technique also assumes that you have set ZERO ON.
   |   STEP 1   |
   Start Forms and create or modify the form region where you want to
   number the tiers. Locate a single-character TEXT variable named VNEW
   in the leftmost spot of the region. Then locate the subnumber column
   (LINENUM in this example) immediately to the right of VNEW. VNEW must
   come before LINENUM in the field list.
   Customize the field settings for VNEW to answer "Yes" to the first two
   questions. Then give VNEW a default value of a pound sign (#). Next,
   customize the field settings for LINENUM to answer "No" to the first
   two questions.
   Locate any other fields you want to have in the tier, and duplicate
   the tier for the region.
   |   STEP 2   |
   Choose "Define..." under Variables, and enter the following six
   expressions in this exact order:
     vnew TEXT = '#'
     vcan INTEGER = (IFEQ(.vnew,'#',1,0))
     vnewnum INTEGER = (INT(.vnew))
     vtest INTEGER = (IFEQ(.vnew,'#',0,.vnewnum))
     vseq INTEGER =  (.vcan*(.vseq+1)+.vtest)
     linenum = (IFEQ(.vnew,'#',(.vseq+1),(.vseq)))
   |   STEP 3   |
   Each time you use the form, you must define VSEQ as an INTEGER and set
   it to zero as shown in this example:
     SET VAR vseq INTEGER = 0
     ENTER formname.
   Now the R:BASE form will automatically number the tiers in the region.
   All you need to do is enter the starting number when the cursor is on
   the pound sign (#).
   Example of How to Use the Form
   When you use the modified form, enter the starting subnumber for the
   region when the cursor is sitting on the pound sign in the VNEW field.
   After you enter the first number, the form expressions take over to
   number the rest of the lines automatically.
   The cursor never enters the subnumber field. It moves up and down the
   rows in the VNEW field that's located immediately to the left of the
   subnumber field. VNEW has a pound sign (#) default. For example, when
   you use the form to edit data, the left side of the tiers in the
   region might look like this:
     # 1  Suit...
     # 2  Shirt...
     # 3  Shoes...
     # 4  Blouse...
   The cursor skips over the number, going from the pound sign to the
   item. To change a line number, enter the new number while the cursor
   is sitting on the pound sign. As soon as you press [Enter], R:BASE
   will move the number to the number column and put a pound sign back in
   the pound-sign column.
   When you use the form as a data entry form, the first line number will
   be wrong. Change it to whatever beginning number (usually 1) you want.
   Then as you move to subsequent rows, the form expressions will
   automatically number the rest of the lines in the region by using the
   increment (usually 1) specified in the expressions.
   Guidelines & Restrictions
   Here are some general guidelines and restrictions:
     o  You must change the first number in the series. Then the form
        will take over from there. You can change a subnumber at any
     o  You may need to change the subnumber again if, for example, you
        enter five rows, and then press [F7] a number of times to go back
        and make changes to previous rows. When you press [F8] to move
        forward again to enter another detail number, the subnumber in
        the next new row will be too high. Change it to the next number
        in the series. Then the expressions will again take over to
        number the subsequent new rows.
     o  This technique may not work correctly if the table that contains
        the subnumber column also contains a computed column. For
        example, this technique won't work with TRANFORM in the CONCOMP
        database because the region's table has a computed column.
   Expressions Explained
   Here's what each expression does:
     o  VNEW sets the variable VNEW to a pound sign (#). VNEW is located
        in the region immediately preceding the subnumber. When you enter
        a new value into the VNEW field, VNEW momentarily changes to that
        value, but as soon as you press [Enter], the form evaluates the
        expressions and sets VNEW back to a pound sign (#).
     o  VCAN uses the IFEQ (if equal) logical function to check and see
        if you just entered a number in VNEW. If you did, the expression
        sets VCAN to zero to cancel subnumber autonumbering. The
        cancellation occurs in VSEQ, which multiplies the result by VCAN.
     o  VNEWNUM uses the INT (convert to INTEGER) function, added in
        R:BASE 3.1A,  to convert any number entered in the VNEW field
        from a TEXT data type to INTEGER. The result is a null value if
        you use INT on a non-numeric TEXT value.
     o  VTEST uses the IFEQ logical function to again test the value of
        VNEW. If VNEW contains a number, the form needs to restart the
        sequence with that number, so it sets VTEST equal to the number
        stored as an INTEGER in VNEWNUM. If VNEW contains a pound sign,
        sequencing should proceed normally, so it sets VTEST to zero.
     o  VSEQ adds one to itself to increment the subnumber. But if you
        just entered a new beginning number into VNEW, VCAN is zero, so
        it cancels the addition, and VTEST has the new number in it so it
        sets VSEQ to the new number.
     o  LINENUM is the INTEGER subnumber column. This expression again
        uses IFEQ to test the value of VNEW. If VNEW is a pound sign, the
        expression sets LINENUM to VSEQ plus one. But if you just entered
        a new starting number, the expression sets LINENUM to that
        number. The value of LINENUM appears in the field on the form and
        is loaded into the table.
   At first glance, you may think the last two expressions will increment
   LINENUM twice, (once in VSEQ and again in LINENUM). But actually
   LINENUM only adds one to the previous value of VSEQ. R:BASE doesn't
   write the new global variable value computed in VSEQ until you save
   the form.
   The value of VSEQ has changed in the form but the dotted global
   variable value has not changed yet. When you use a dotted global
   variable to the right of an equal sign, R:BASE reads the old dotted
   global variable value, not the form expression value. Both the VSEQ
   and the LINENUM expressions read the same old global variable value
   for .VSEQ, so you need to increase both VSEQ and LINENUM for each row
   in the region.
   The VSEQ expression ensures that once you save that row, the VSEQ
   global variable will be increased by the increment in the VSEQ
   expression making it ready for the next row.
   Changing the Increment
   To use an increment larger than one, change the VSEQ and LINENUM
   expressions. For example, to increment by five instead of one, define
   the two expressions this way:
     vseq INTEGER = (.vcan * (.vseq + 5) + .vtest)
     linenum = (IFEQ(.vnew,'#',(.vseq+5),(.vseq)))
   Expression Processing Examples
   Here's an example to show you how the expression values change. Say
   you are moving from the fourth to the fifth line in the region. The
   last row you saved changed both LINENUM and VSEQ to 4. Here's how the
   expressions evaluate in the fifth row:
     o  vnew = #
     o  vcan = 1
     o  vnewnum is null because
     o  vtest = 0
     o  vseq = (1 * (4 + 1) + 0) = 5
     o  linenum = (4 + 1) = 5
   Now, say you move on to the sixth row in the region. Here's how the
   expressions evaluate:
     o  vnew = #
     o  vcan = 1
     o  vnewnum is null
     o  vtest = 0
     o  vseq = (1 * (5 + 1) + 0) = 6
     o  linenum = (5 + 1) = 6
   Next, say you enter a new number in VNEW (the pound sign) to make the
   next row 8 instead of 7. Here's what happens in the expressions:
     o  vnew = 8
     o  vcan = 0
     o  vnewnum = 8
     o  vtest = 8
     o  vseq = (0 * (6 + 1) + 8) = 8
     o  linenum = 8
   Here's the next record:
     o  vnew = #
     o  vcan = 1
     o  vnewnum is null
     o  vtest = 0
     o  vseq = (1 * (8 + 1) + 0) = 9
     o  linenum = (8 + 1) = 9