form in form problem

 Hi, Adi!
             I may not an expert to give a conclusion for your problem.
             With the 'SKILL' I have I tried to solve your problem. This too will have a disadvantage, check it out in the end of this message.
The answer for " WHY? " in your post is as follows ...
Since your " printf "  statement is in testforms(And you are calling it only once) this will not be displayed again & again.
I made few modifications to your code ...
/******************starts here**************************

 Thank you for your answer and your sugestions; I will try to resolve the problem with a solution based also on the callback of the form; 

Doing more tests I succeded to simplify theexample which causes my problem:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  procedure( testforms()
    let( (form)
        form = hiCreateAppForm(
            ?name 'firstForm
            ?formTitle "First Form"
            ?buttonLayout 'OKCancel
            ?fields list(   list(hiCreateButton( ?name 'theTestButton
                                               ?buttonText "Test Button"
                                               ?callback "TestButtonCollback()")  230:10 140:30) )
        )

        hiDisplayForm(form)
        
        printf("First form is finished; Ok button or Cancel button was pressed;")
    )
)


procedure( TestButtonCollback()
    let( ()
        hiFormCancel(firstForm)

        hiDisplayForm(firstForm)
    )
)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I call the procedure testforms(), the form "firstform" appears, I press the button, the form is canceled and immediately displayed, then I close the form and ... no string is printed (from the printf) ...

Probably is the way Cadecne handles the forms; But .. is there any method to resolve this? I think that no matter what I would do in the form "firstForm", when it's finished (closed with OK or Cancel button), it should return to it's coresponding hiDisplayForm() and to next instructions placed after;

Best Regards,

Adi.

Hi Adi,

The fundamental problem is that forms are (by default) blocking. This means that when you display the form, the SKILL execution of the procedure which calls the hiDisplayForm blocks until the form is OK'd or cancelled. In your first example, the callback from the "Test Button" is blocking  execution. I think that procedurally calling hiFormCancel in a callback does not get the corresponding hiDisplayForm to continue execution. In fact in your second code, if you do:

1. testforms()
2. hit the "Test button"
3. hit OK
4. testforms()
5. hit OK

You'll see the printf message appears twice. Finally the forms got unblocked.

In general, writing code that depends on the blocking behaviour of the forms is bad practice. The right way to interact with a form is to use the form callback (specified in the hiCreateAppForm() call) - this way you are completely isolated from the blocking nature of the form. You can also ensure that forms don't block by passing ?dontBlock t to hiCreateAppForm(). Note that you can have two callbacks for a form - one for OK and one for Cancel. The additional benefit of callbacks is that if you have an Apply button on your form, the callback would be triggered by that too.

Regards,

Andrew.

 Hy Andrew,

Thank you for the explanation, I understand your sugestion. I will try to avoid this kind of code (like in my examples) and use only the callbacks. Like you said seems that everything is acting normally, but one little stream of ideea remains in my head regarding the missing reson of the strange relation between each hiDisplayForm and it's coresponding hiDisplayCallback; 

Thank you,

Best Regards,

Adi.