Preserving Field Data - confused again!

[Simon Knight]

Hi,
I have a stack that has a single card. When run the user may enter some calibration data which I would like to have available when the application is next run. My plan was to build the application as a standalone but the following copied from the dictionary suggests that it is a little more complex ":You cannot save to a standalone application's file; standalones are read-only."

How would you experts store a single value between runs of a standalone?

Thanks

Simon

[bn]

Simon,
a standalone can not save data to itself. There are several options to save data from the standalone. You can save it to a file, which is in the folder where the standalone is. This is a little tricky to find the paths for mac and windows, since they are not the same, you could also save to a folder in the user domain (documents or mydocuments) which you create and control.

What I would suggest is called the splash screen approach. The compiled standalone stack acts as a splash screen, it does not do much except starting, may be showing a, well, splash screen, now the important part: it calls up a second stack that you include in the list of stacks to include when building the standalone, which has all the logic and functionality of your application. The splash screen hides itself.
The beauty of this is that the second stack, with your logic is just a file, not an application. That is why you can save it with changes the user made.
This is explained well in the "Standalones" section of the scripting conferences.
http://support.runrev.com/scriptingconferences/
there you will want to look for: Script Library

You could use your present stack as is and save the calibration data in this stack, just make a splash screen stack that calls your current stack and you are all set.
regards
Bernd

[Simon Knight]

Bernd,
Thanks yet again for pointing me in the right direction. I have created two stacks and have the process working, which is good , but I am uncertain how it happens How and where is the field value saved in the 2nd stack? Indeed where is the second stack once the application is compiled. I'm guessing that the act of compilation adds the "Run" part of the development environment to the stack/s being compiled as the .exe gets quite large but I don't see how an included stack gets written to without there being a file. My head hurts.....

best wishes

Simon

[bn]

Simon,
no head hurting necessary.
On a Mac your app is actually a folder. If you hold down the control key while clicking on your application a dialog appears and you choose show package content. A new folder opens and it shows your TestApproximator and the TestStack.rev. TestStack.rev is actually a stack = file, which is where your data is saved. That is all. The nice thing about using the stack as a repository of data is you don't have to worry much about where it is. It is right in the application bundle on a Mac and stays there.
I don't know where it is on Windows, but must be similar.
regards
Bernd

[Simon Knight]

Bernd,

CLANG - thats the sound of the penny dropping (as we say!)

I have just compiled my application to windows and windows displays the extra stack file alongside the exe file. I had forgotten all about Mac packages ( an idea borrowed from Acorn !Application directories). It is a lot clearer now, thanks again.

Simon

[FourthWorld]

This AppPath function can help you find the path to the app whether running as a standalone on Mac or Win, or even as a stack file within the IDE:

Code: Select all

function AppPath
  put the filename of this stack into tPath
  set the itemdel to "/"
  If (IsOSX()) then
    get offset(".app/Contents/MacOS/", tPath)
    if it > 0 then -- 2.4.3 or later
      delete char it to len(tPath) of tPath
    end if
  end if
  delete last item of tPath
  return tPath &"/"
end AppPath

function IsOSX
  if the platform is not "MacOS" then return false
  get the systemversion
  set the itemdel to "."
  if item 1 of it >= 10 then return true
  return false
end IsOSX

But unfortunately OSes have made it a little harder in recent years for saving as opposed to just reading: Vista, Win 7, and OS X now support multiple user modes, and only administrators will have permission to write to the Program Files or Applications folders.

This article by Sarah Reichelt at revJournal.com shows how to use Rev's specialFolderPath function to find the appropriate user-writable directories to save data on Mac and Win:

http://www.revjournal.com/tutorials/sav ... ution.html