Some Basic Misunderstandings/Problems with RunRev - aka Help!

[David Burgun]

>Hello Dave,
>
>>  Date: Wed, 14 Apr 2004 18:03:19 +0100
>>  From: David Burgun <dburgun at dsl.pipex.com>
>>  Subject: Re: Some Basic Misunderstandings/Problems with RunRev - aka
>>  Help!
>
>>>>  Why doesn't the documentation say anything about this?
>>
>>  I mean that if you look up the "save" command it makes no mention
>>  that you can't save a stack if it's a Standalone. In fact I've found
>>  the dictionary good for checking the syntax of a command/message but
>>  absolutely useless for putting the command/message into context.
>----------
>???
>
>Here is a copy/paste _directly_ from the Dictionary:
>
>*** You cannot save to a standalone application's file; standalones are
>read-only. ***
>
>...Without trying to be pretentious, that seems fairly plain to me.

You are right, it does say that, sorry I just didn't see it when I 
was looking up the command. What would have been nice would have been 
for it to be in Bold and for some pointers on how to do it another 
way.

>I believe I understand what you want to do. One of the things I do is build
>ableware/adaptiveware stuff. These have a bunch of options and controls
>which need to be saved.
>
>A standalone contains the Rev/MC engine, which does _not_ allow saving to
>itself, which is common industry-wide.
>
>For this reason, most Rev developers use the Splash (Richard says to make a
>memory error dialog so you don't leave the user wondering what happened if
>the thing sucks up too much memory at startup...I tend to favor this
>approach myself) as the Main stack, i.e., it contains the engine, which,
>after initialization (globals, etc,)
>
>Consequently, your GUI should have been developed as a substack, initialized
>and opened by the Splash (which is really the Main stack with the engine).
>When you close, you save this substack from the Main stack. It will be saved
>with whatever changes you made to it.
>
>The question then becomes: How does your stack operate according to the
>settings?
>
>Way #1
>
>My first suggestion if you have backup issues or want to otherwise ensure
>the safety of the settings, is to save values that relate to your controls
>in a text file as has already been suggested. This is the safest way,
>because it's easy to save, easy to back up anywhere, easy to recover, and
>can be read by other apps if your standalone takes a crap, or you want to
>change it and something goofs up.
>
>Way #2:
>
>You could simply have each routine that needs to know the status of a
>checkbox check to see if it's hilited via a path, on the fly. But that's
>slow, inefficient, and totally vulnerable. You'd need to backup the whole
>thing, GUI and all, or else, if it goes down, you lose everything.
>
>Way #3:
>
>If you feel you must save within the GUI, then save the status of the
>controls in both global variables and in the lines of a _hidden field_. When
>you change a control, put it's status value into a global variable as well
>as the designated line of the hidden field. This way, when the stack starts
>up, it reads the values from the hidden field into the globals in an
>initialization routine. Then all your routines need to do is operate off the
>status values in the globals.
>
>BTW, in the text file save scenario, it does essentially the same thing,
>except it's safer.
>
>I sincerely hope this helps and makes sense.

Yes, Ken it makes a lot of sense, but it's not really applicable in 
this case, although in another App it might make sense to do it this 
way.

All I want is to save the state of the complete GUI. There is no user 
data that is entered or modified. If I change the controls of a 
Stack, then the whole of the GUI data becomes invalid anyway, so just 
replacing the stack file and resetting back to the factory settings 
will be fine.

As far as a backup is concerned, I may well just copy the stack into 
a backup folder when the Main Standalone is launched, but apart from 
that there is no real user data to back up!

I think that this App must be different from most RunRev apps that 
are out there.

Best Regards
Dave