Liren Large Software Subsidy 5/05.iso/a/a074/1.img/READ.ME

Text File | 1991-04-29 | 9.9 KB | 276 lines

╔══════════════════════════════════════════════════════════════════════╗
║                             CALC(DB) 1.0                             ║
║                            April 26, 1991                            ║
╚══════════════════════════════════════════════════════════════════════╝

Since the printing of the User's Manual for CALC(DB) a number of new
or updated features have been added. This new stuff is documented
here and

     SHOULD BE PRINTED FOR FUTURE REFERENCE!

The next generation of the manual will have all these updates
incorporated but for now this is the *ONLY* place that they are
documented.

A brief table of contents is supplied for easy reference.

     Requirements
     New @function: @UDF
     New Macro Commands
          {REVERT}
          {RECALCUDF}
          {EXIT}
     Misc. Macro Stuff
     New Menu Commands
          Worksheet-Revert
          Worksheet-Global-Recalc-UDFs
     New API Functions
     Memory Management
     Important Notes
     Credits


╔══════════════════════════════════════════════════════════════════════╗
║                             Requirements                             ║
╚══════════════════════════════════════════════════════════════════════╝

CALC(DB) requires Clipper version 5.01 or greater.  The DEMO program
requires expanded memory to work with all the example spreadsheets.


╔══════════════════════════════════════════════════════════════════════╗
║                                 @UDF                                 ║
╚══════════════════════════════════════════════════════════════════════╝

CALC(DB) introduces a new @Function to the spreadsheet world:

     @UDF

This function can be used to call a Clipper UDF directly from a
spreadsheet formula.  The return value from the UDF is placed in the
cell as its value.

In spite of its apparent size, @UDF is *NOT* A MINOR ADDITION!

In fact, through this @function you can access the full power of Clipper
as an integrated part of your system.

The biggest advantage to using @UDF over an embedded UDF in a macro is
that the @UDF will be called every time data is changed or recalculated
in the worksheet.  This, in essence, gives you the power of an
event-driven engine from within Clipper.

Take a look at the sample spreadsheets included with CALC(DB) to get
some idea of the power inherent here.  Also, read the next few
paragraphs carefully to understand the current limitations of this
function.

The calculation of @UDF functions is controlled by the Object Variable
cdCalcUDF in the Spreadsheet Object.  When cdCalcUDF is set TRUE all
@UDFs are recalculated whenever the spreadsheet is modified.

The syntax for @UDF is very similar to the syntax for calling Clipper
UDFs from macros.  The Clipper function should appear as it would be
called from within Clipper code.  For example:

     @UDF(MEMORY(0))

would call the Clipper MEMORY() function and place the return value in
the cell.  As with UDFs called from macros, the current Spreadsheet
Object is passed as a final parameter to the function you call using
@UDF.

@UDFs must be used alone in a cell, and cannot be nested within normal
@Functions.  To use the return value from an @UDF in another formula,
simply place the @UDF in its own cell and reference the cell from the
formula.

NOTES:

@UDFs will not appear if the spreadsheet is read using another
spreadsheet program.  Also, if a spreadsheet containing @UDFs is
modified and saved using another spreadsheet program, @UDFs are not
saved in the new/modified spreadsheet.

You must be sure that all functions referenced in @UDFs are linked into
your application.  If an @UDF references a function that doesn't exist
it will show the value as ERR.  Any functions that are not explicitly
called from you Clipper code must be declared as EXTERNAL. One way to do
this is to place EXTERNAL declarations for all your spreadsheet UDFs in
a header file and #include it in your main source file.  (See the
Clipper documentation for more information on external functions and
header files.)


╔══════════════════════════════════════════════════════════════════════╗
║                          New Macro Commands                          ║
╚══════════════════════════════════════════════════════════════════════╝

{REVERT}

     Reverts the spreadsheet to the last saved version.

{RECALCUDF}

     Recalculates @UDFs only

{EXIT}

     Exits cd_Browse() - equivalent to /-Quit-Yes


╔══════════════════════════════════════════════════════════════════════╗
║                          Misc. Macro Stuff                           ║
╚══════════════════════════════════════════════════════════════════════╝

UDFs in macros no longer have to be in their own cell or the last
command in a cell.


╔══════════════════════════════════════════════════════════════════════╗
║                          New Menu Commands                           ║
╚══════════════════════════════════════════════════════════════════════╝

Worksheet-Revert

     The Worksheet-Revert menu command reverts the current spreadsheet
     to the last saved version.  This command can also be executed using
     the new {REVERT} macro command.

Worksheet-Global-Recalc-UDFs

     There are new menu commands to facilitate the recalculation of
     @UDFs in your spreadsheets.  The UDFs selection presents a new
     sub-menu with the following options:

     With Recalc

          Causes all @UDFs to be recalculated whenever a normal
          recalculation occurs (when spreadsheet is changed if autocalc
          is on, or F9 is pressed).

     Manual

          @UDFs are only recalculated when Worksheet-Global-Recalc-UDFs-
          Right Now! is selected or {RECALCUDF} macro command is
          executed.

     Right Now!

          Recalculates all @UDFs.


╔══════════════════════════════════════════════════════════════════════╗
║                          New API Functions                           ║
╚══════════════════════════════════════════════════════════════════════╝

cd_FReadCell()

     Syntax:

          cd_FReadCell(cFileName, cCellAddr | cRangeName)

          cFileName = Name of the spreadsheet file to read from

          cCellAddr = Address of cell to read (ie. "A1")

          cRangeName = Range name for cell to read


     Return Value:  <?> value contained in cell (NIL if cell is empty)

     Description:  Opens spreadsheet file and reads the value from the
     specified cell.  If a range name is specified the value is returned
     from the upper-left cell in the range.

     Note:  This function can be used to establish "relational"
     connections to other spreadsheets/datafiles.  See the DEMO_UDF
     worksheet to examine a sample of this.


╔══════════════════════════════════════════════════════════════════════╗
║                          Memory Management                           ║
╚══════════════════════════════════════════════════════════════════════╝

Providing this much functionality in a Clipper environment requires a
considerable amount of memory.  Upcoming versions of CALC(DB) will
support virtual memory, but in the meantime here are a few things to
keep in mind when using CALC(DB):

Expanded Memory

     This version will only store numbers and certain cd_Browse()
     environment data in expanded memory.  Expanded memory is highly
     recommended when using this product, but not absolutely necessary.

Overlays

     Overlays should be used when using CALC(DB).  The CALC(DB) library
     is divided into two separate files - CDBROOT.LIB and CALCDB.LIB.
     CALCDB.LIB contains functions that can be overlaid.  We have
     included some linker response files to demonstrate some more
     effective ways of dividing up overlays.  So far, the most effective
     linker for our testing purposes was BLINKER by Blink Inc. The other
     linkers we tested for compatibility were RTLINK (for Clipper),
     RTLINK 4.1, and Microsoft Link.

Limit Spreadsheet Size

     Spreadsheets should be kept as small as possible to avoid
     exhausting memory.  The use of spreadsheet objects makes it easier
     to divide large projects into smaller spreadsheets.


╔══════════════════════════════════════════════════════════════════════╗
║                           Important Notes                            ║
╚══════════════════════════════════════════════════════════════════════╝

Lotus 1-2-3 password-protected worksheets can not be used with CALC(DB).

Named graphs stored in spreadsheets are not retained in files saved
using CALC(DB).


╔══════════════════════════════════════════════════════════════════════╗
║                               Credits                                ║
╚══════════════════════════════════════════════════════════════════════╝

Most importantly are those people who made this product possible.  As
always it is impossible to name them all, but a few stand out and
deserve the attention.

-BJ Walsh, the Director of Software Development at SuccessWare and team
leader on this project.  Incredible talent.

-David Johnson, who started this whole mess.

-Tzvi Rozenman, who supplied the core spreadsheet technology.

-Ira Emus, whose last minute "suggestions" made CALC(DB) considerably
more robust (and slowed the release of the product by two weeks).

And to Lori, Corey and Holly, my "other" family, the ones who sit at
home waiting for me...

Thanks y'all.  HiHo,

Jeff Jochum
President
SuccessWare 90, Inc.
May 1, 1991

╔══════════════════════════════════════════════════════════════════════╗
║                      CALC(DB) is published by:                       ║
╚══════════════════════════════════════════════════════════════════════╝

Pinnacle Publishing, Inc.
28621 Pacific Highway S.
Federal Way, WA  98003
[phone]
[phone] (Sales)
[phone] FAX
[phone] Technical Support
[phone] BBS (2400-8-N-1)