UDF's ... and that Masked Magician!

[G Gabriel]

For 2 years, Val Valentino wore a mask and revealed on TV the secret behind one magic trick after another.

What a looser!

Not only he ruined it for the magicians, but worse (I think) for the audience. You no longer wow when you see these magic tricks since now you know how they are done.

In one thread after another, I have heard enough from those who wow about UDF's and what they do, making UDF's look like magic tricks. Debating & debunking myths doesn't seem to make anyone change their mind that Santa is only an imaginary figure. There is no point in debating anymore. So now what: reveal the magic? I am not that stupid to repeat Valentino's blunder and make a looser out of myself. So, rather than delving into the magic behind the UDF's, I let you figure it out for yourself.

Run this simple test, and see what you think.
1-Create & save this function:

FUNCTION reset_x AS C ( )
	ui_modeless_dlg_box("Reset X",<<%dlg%
	{position=2,2}
This function resets the value of X to: "B";
{lf};<Close>
%dlg%,<<%code%
sleep(1)
x="B"
if a_dlg_button="close"
	ui_modeless_dlg_close("Reset X")
	end if
%code%)
END FUNCTION

Now run the following script:

dim global x as c="A"
reset_x()
ui_modeless_dlg_box("result of X",<<%dlg%
The result of x is: {text=20,2 x};
<Close>;
%dlg%,<<%code1%
if a_dlg_button="close"
	ui_modeless_dlg_close("result of X")
	end if
%code1%)

Then run this script:

dim global x as c="A"
	ui_modeless_dlg_box("Reset X",<<%dlg%
	{position=2,2}
This script resets the value of X to: "B";
{lf};
<Close>
%dlg%,<<%code%
sleep(1)
x="B"
if a_dlg_button="close"
	ui_modeless_dlg_close("Reset X")
	end if
%code%)
ui_modeless_dlg_box("result of X",<<%dlg%
The result of x is: {text=20,2 x};
<Close>;
%dlg%,<<%code1%
if a_dlg_button="close"
	ui_modeless_dlg_close("result of X")
	end if
%code1%)

What do you see? and what do you think?
This simple test should give you, not only a lot of insight on UDF, but also and as an un-intended consequence, help you better understand how xdlg work.
Have at it.

[Keith Hubert]

Re: UDF's ... and that Masked Magician!

Hi Gabe,

I think you have managed to misdirect us very well.

I don't see the rabbit coming out of the hat, in fact I don't even see the hat.

What are you trying to demonstrate, to whom and what purpose?

[Tom Cone Jr]

Re: UDF's ... and that Masked Magician!

Keith, I think in part G is illustrating that it's possible to write a UDF which will not force Alpha to wait on the function to return a result before continuing on with the calling script. To see this more easily change the second line in his UDF to a modal xdialog like this:

ui_dlg_box("Reset X",<<%dlg%

Notice that with this change Alpha waits for the modal xdialog to close before continuing in the calling script.

You can see the same thing in other contexts. If you create a udf that does nothing but open a form, and then create a script that calls the Fn twice in a row, two instances of the form are opened. The script does not wait to open the second instance until the first called form is closed.

[MikeC]

Re: UDF's ... and that Masked Magician!

I see what Tom is seeing--

The script does not wait to open the second instance until the first called form is closed.

Exactly....and expected really. Alpha waits for the UDF to finish before proceeding to the next part of the script...not anything within it to close such as a form and such.

I guess I do not see the point of the exercise either, unless it is to point out to some that were thinking about this in error. But of course I could have missed something as to the purpose of this I admit.....



EDIT LATER: After checking it out further, I do see the value of what G is saying....it still makes sense to me that the script continues though....as that is what the UDF basically is telling Alpha to do by loading a modeless xdialog (or form)--to allow the script to continue.

So good point G!! Thanks!