[Gambas-user] Return value from message box in webfrom application

[Benoît Minisini]

Le 10/01/2019 à 09:40, Michele V. a écrit :
> Hi to all
> How is possible le to know the selected button in message box used in 
> webform application?
> No return value is provided by the function
> 
> 
> Thank you
> 
> Michele
> -------------------------------------------------------------------------------------------------------------------------------------------
> Io scrivo da UBUNTU GNU/LINUX
> 
> 
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> 

gb.web.form (obviously?) does not allow any user (i.e. browser) 
interaction inside a request.

The trick is the following: any control raises a "Message" event when a 
message box has been opened from one of its event handler.

It works like that:

----8<------------------------------------------------------------------

' The remove button Click handler that opens the message box.

Public Sub btnRemove_Click()

   Message.Question(("Do you really want to remove this file?"),
     ("Cancel"), ("Remove"))

   ' Execution continues here. The message box will be opened by the
   ' browser when the request is returned to it.
   ' You can even open other message boxes. But it's not a good idea.

End

' The Message event that gets the message box answer.

Public Sub btnRemove_Message((Source) As WebControl, Action As String)

   If Action = ("Remove") Then

     ' Remove the thing

   Endif

Catch

   Message.Error("Unable to remove this thing!")

End

----8<------------------------------------------------------------------

You should note that there is another message in the btnRemove_Message() 
method. It will call the btnRemove_Message() again! So you must be 
careful to make the difference between the answers of the different 
message boxes.

The last behaviour is not very clean, so if I find a different way to 
get the message box answer, I will implement it. It could be based on a 
message box identifier, I don't know yet.

Regards,

-- 
Benoît Minisini