DB Access in standalones

[J. Landman Gay]

On 8/19/03 1:21 PM, Devin Asay wrote:

> What is the real story here? The documentation is not very detailed on 
> this point, and in fact does not seem to reflect what's really 
> happening. Can someone on the Rev team explain it to me? Tuviah? Geoff? 
> I really need to get this application up soon. Thanks.

I would also appreciate an explanation from someone who knows. After I 
answered you yesterday, I spent almost five hours wrestling with exactly 
the same problem. I never could get the external to load properly. Like 
you, I tried a startup handler that called revSetDatabaseDriverPath but 
it did no good. I also moved all the scripts from a substack that 
contained the DB calls into the main stack script but that didn't help 
either. I tinkered with scripts endlessly and probably built 40 or 50 
trial standalones, none of which worked. The stack works fine in the IDE.

This should not be so hard, and I suspect there is a problem with either 
the engine or the distribution builder. I did find an error in Rev's 
database library scripts which I thought could be the problem, but 
fixing it still didn't cause the externals to load for me.

Even so, you will probably want to try fixing Rev's DB library script. 
It's in the stack called "revlibrary.rev", which contains a group that 
gets copied to your standalone during a build. You'll need to edit the 
script of the group called "revLibraries" which contains a 
preOpenBackground handler. That handler starts out like this:

on preOpenBackGround
   repeat with i = 1 to the number of btns in me
     if the short name of button i is among the items of 
"revTable,revDatabase" then
       insert script of button i of me into front
     else
       insert script of btn i of me into back
     end if
   end repeat

If this group isn't the first one placed on the card in the standalone, 
the script will fail to insert the database lib scripts in some cases, 
and will insert non-database button scripts arbitrarily from other 
buttons in your stack. If that happens, all Rev-related database calls 
will fail. The fix is to change line 3 to this:

  if the short name of button i OF ME is among the items of 
"revTable,revDatabase" then

This ensures that the right set of button scripts are inserted. (It took 
me forever to find this bug, since you can't look at the group's script 
once it is in a standalone.) I've bug-reported it and Runtime fixed it 
yesterday, but people will probably want to alter their current copies 
of the library to accomodate until the next release comes out.

I thought this fix was the clincher and things would work properly after 
that, but as I said, the external still didn't load even with the 
revised library script. I am not at liberty to send Runtime the stacks I 
am working on, but if you can send them yours, I hope you will. It seems 
to be a common problem for many of us and I'd like to see it resolved 
soon. As near as I can tell, there are some stacks which simply cannot 
use the database externals in OS X.

-- 
Jacqueline Landman Gay         |     jacque at hyperactivesw.com
HyperActive Software           |     http://www.hyperactivesw.com