Say it ain't so regarding "Save" command!

[Mark Wieder]

Donald-

Saturday, July 30, 2005, 8:49:42 AM, you wrote:

DA> Can a user enter and then save info into a standalone application?  Or
DA> something?

Sure. There are any number of ways to do this. Rev would be a pretty
sorry excuse for an app builder if you couldn't.

The problem you've run across is that applications can't modify
themselves. This isn't something that's peculiar to rev - it's built
into the operating system. So you need to do something else.

One way would be to save data in text files. Or use a database. Or
some other format as an external file.

Another way is to have a mainstack and substacks as separate files.
The main stack can modify the substack files without any problem. I
have some apps where the main logic is in the mainstack and the data
is in separate substacks. Just remember when you're building the
standalone to specify that the substacks should be separate.

A technique that builds on this is to have your mainstack nothing more
than a splash screen that then launches a substack with the program
logic and other substacks for the modifiable data. This makes updating
the program for your users easy because you just have to ship the
small program substack.

You can also clone a substack in memory and save it as a separate data
stack, then remember to load it when you start again. Or allow the
user to load one of several saved data substacks.

-- 
-Mark Wieder
 mwieder at ahsoftware.net