Display date() as a global variable

[Hans Otto]

Some months ago I launched an inventory runtime application to my first customer. A standalone desktop app. A5 V8. It all functioned as planned, including a global date variable acting as a date stamp for new records ( new or changed) in various tables. The variable is visible in the main menu when the application starts. It is a fixed date: 01.01.2007. As the user creates new records, she can alter that date to any date, and the global date variable stamps new records with the new value until she changes it again.
But now she wants that fixed date prefered to show today's date initially on the main menu. Simple I thought, but I am stuck. The autoexec script maybe, but the variable does not show up on the main menu initially, and if I define the variable in design mode for the menu form, it only takes a fixed date value.

[Mike Wilson]

Re: Display date() as a global variable

how about an xdialog fired on start up or main menu initiation?

DIM global vgdStamp as D
vgdStamp = date()

dbxR = ui_dlg_box("DATE SET",<<%dlg%
{lf=.5};
{region}
{lf};
{justify=center,center}[.20vgdStamp];
{endregion};
{line=1,1}
{region}
{lf};
{justify=center,center}
<*10OK!OK> <10Cancel!Cancel> 
{endregion}
%dlg%)

	SELECT
		CASE dbxR = "OK"
			msgbox(dtoc(vgdStamp))
		CASE dbxR = "Cancel"
			end			
	END SELECT

[G Gabriel]

Re: Display date() as a global variable

Put a calc field in the main menu:
today_date=date()

[Hans Otto]

Re: Display date() as a global variable

Mike, thank you, for that dialog box idea. It worked! Actually you made me realize a very simple solution:
First; design mode for the startup application menu: Define New Variables, Global Variables:
Bdato = { . . }
Second, regarding Event for that menu form, I now have two:
OnInit: Bdato = date()
OnActivate: Refresh Objects (action)
That�s all I need.
You see, I have a Type-In Field on that menu form containing that global variable Bdato and it needs to be refreshed when the user returns from a table and back to the menu.
But I need to investigate why that autoexec script did not pass the date() value initially. I added two actions to the script, DIM variables and �set a variable to a constant�. No luck, so I need to find some debug function in order to see the actual value of the variable.
Gabriel, I take that Calc Field idea as well, showing today�s date on the menu.
Thanks for involving in my learning progress :)

[CALocklin]

Re: Display date() as a global variable

Why won't it work from the autoexec? It's done all the time unless I missed something in the request.

DIM GLOBAL vgdStamp as D
vgdStamp = date()

Once that is defined in the autoexec - which runs before any forms are opened - any future references to it will show today's date until someone changes it to something else.

In the main menu, define the variable as global and leave it blank - or set it to anything you want. That particular value will only be set IF the variable hasn't already been set. Once the variable has been set (i.e., 'exists'), the definition in the layout will not override it.

[G Gabriel]

Re: Display date() as a global variable

And why in the autoexec? why not in the OnInit or OnActivate event of the main menu?

[MoGrace]

Re: Display date() as a global variable

Hans if you are using a global variable then be sure to dim it as global everywhere you want to use else your script may be referencing a variable of a different scope.

[CALocklin]

Re: Display date() as a global variable

And why in the autoexec? why not in the OnInit or OnActivate event of the main menu?

No special reason. I was just addressing the concern stated in the last sentence of the original post about putting it in the autoexec. Personally, I prefer the autoexec only because, in my opinion, it's a bit more "obvious" if I'm looking for it a year later or if for some reason I decide to use a different form for startup. (Changing to a different form is certainly unusual but it has happened.)

If Hans actually tried to set a global variable in the autoexec then display it on the main menu and it didn't work, he must have done something wrong. Defining global variables in the autoexec and displaying them on the main menu is something I've done, and seen done by others, on a regular basis. I consider it standard practice and take it for granted that the process will work. Perhaps he forgot to define it as a global variable and/or to run the autoexec first in order to initialize the variable before placing it on the main menu. (Yes, there are also other ways to initialize the variable. The point is that it must be initialized before it will show up on the form.)

Although it isn't necessary, I often define the variable in the form also. Doing that for normal use of the app has no value because the variable should have already been defined before the menu was opened. However, there are sometimes situations during development where I've bypassed the autoexec and then opening the form generates errors. Others have expressed the opposite opinion - NOT defining it in the form will cause an error for the user in case something was wrong. (But I never make mistakes so I don't worry about that.)

[Hans Otto]

Re: Display date() as a global variable

If Hans actually tried to set a global variable in the autoexec then display it on the main menu and it didn't work, he must have done something wrong.

Yes, I did something wrong, because I trusted the Alpha Genie (Action Scripting).
Action called �DIM variables� does not have an option for GLOBAL variables, it has to be declared in the Variable name field together with the name itself. Now the autoexec script works as intended:

'DIM variables
DIM Global Bdato AS D
'Set the value of one or more variables.
Bdato = date()

[Hans Otto]

Re: Display date() as a global variable

be sure to dim it as global everywhere you want to use else your script may be referencing a variable of a different scope.

Is this really necessary or is it just in case?

When I declare the Global variable in the autoexec script, isn�t that valid for that Database all through the session?

The way I keep control of the global variable is in the field rules of the tables. The datefield that is �stamped� has a default value = VAR->Bdato. If the user changes the date for a certain record, then the global variable get that new value from the Events tab sheet of the Field rules definition. Creating a browse window based on the same table does not need a new �DIM Global Bdato AS D� (design mode of browse table).

[MoGrace]

Re: Display date() as a global variable

For me I guess it is just in case. You are right in that if its inital scope is global then you ought to be able to call it without dimming it again. I have been working at changing my global variables to shared so I can use them with more versatility. For shared you definitely need to dim them each time.