dynamic small list xdialog as buttons

[Mike Wilson]

Hi,
I don't know if this will have any use for anyone, but I thought I would throw it out there.

I am lazy. I use alot of displays for the user to make choices. I have typically used list dialogs presented to the user from a form button for this purpose. With the form button :
1. The xdialogs present the selection choices as a list in a list dialog to the user for selection.
2. The user selects the item.
3. The user presses the OK button.

The great advantage in above approach is the input list size can be variable and list box will accomodate it with the list and a scroll bar to access the list items beyond the lists hard coded size. This can be changed with special coding but it is still is a three step process. Why not a two step process for small lists? Display an xdialog that dynamically presents selections as buttons instead of a list requiring list selection and a button press.

The blue sort buttons compare the two ways for presenting the user choices dynamically in an xdialog, one as a list and the other as dynamic xdialog buttons. It works for small lists that may change. I thought I would throw it out there for fun. The Navigator button also works code that displays the dynamic xdialog as buttons.

[Lance Gurd]

Re: dynamic small list xdialog as buttons

The above database got me in a never ending loop giving the message

 That I should send the following line to Alpha technical - Source code (not on your machine) C:\Dev\a5v9\src\LANGUAGE\EXPR\sysevent.cpp at line 281.

Beware!!

some nice stuff in there though

bug report sent

[Mike Wilson]

Re: dynamic small list xdialog as buttons

Odd,
I downloaded this on a few machines and I got no issues.

[Lance Gurd]

Re: dynamic small list xdialog as buttons

Have not seen one of these type messages since version 5!! but it is there, just ran it again and have to use task manager to close Alpha 5

[Mike Wilson]

Re: dynamic small list xdialog as buttons

Lance,
I downloaded this to a few machines... no problem. However, there are two dim statements in lines #17 & 18 of the company_sort() UDF that should not be there:

dim shared vLenum as N
dim shared vwide as N

I have my xdialog font system settings to Arial,10, as in the script, so I do not see a vertical scroll bar in the list dialog.

[Mike Wilson]

Re: dynamic small list xdialog as buttons

This tells me the Xexitlock script run on startup through the autoexec somehow is not running. The error you are seeing is from running the code on the exit button which is supposed to fulfill the can_database_exit() lock established in the Xexitlock script.

[MikeC]

Re: dynamic small list xdialog as buttons

Not having any problem here using version 8--I can use the form's "X" to close however but no errors.

I have never used the system_event_drop() function but seems to me that maybe it should be

system_event_drop("database_exit", "1")

instead of what you placed:

system_event_drop("database_canexit","1")

Just a guess from my limited reading of it.


---Mike, in what version was this created??? --always nice to know when trying out samples and such!

[Mike Wilson]

Re: dynamic small list xdialog as buttons

Mike,
The docs says system_event_drop("database_exit", "1") but that does not work in my hands. Only system_event_drop("database_canexit", "1") works for me. And you apparently.

Lance,
Run this and see if it works. If you get an error run it as ptr.database_canexit and see what happens.

 dim ptr as P
ptr = system_event_data_get()
? ptr.database_exit

This code originated in v7 and the example finished in v9. Thanks for the heads up re: the version being exampled. Usually it is in a particular forum so that needs not be said.

[Lance Gurd]

Re: dynamic small list xdialog as buttons

Ran the code as requested in the interactive window and got the following

ERROR: Unexpected internal Alpha Five error.
Please send the following information to technical support at Alpha Software.
Source code (not on your machine) C:\Dev\a5v9\src\LANGUAGE\EXPR\sysevent.cpp at line 444.
ptr.database_exit subelement not found.

Therefore what I am seeing is an internal Alpha 5 error, which was reported to them on Friday, no news yet

[brett s]

Re: dynamic small list xdialog as buttons

Here are some tips based on my experience with the function 'SYSTEM_EVENT_DATA_GET()'. It exhibits some petulant behavior resulting in obscure error messages just like those mentioned above. The A5 documentation gives examples but they only work in the interactive panel. If you try them in your Xbasic script you will get an error of the type shown.

It's easy enough to create and delete system events using the Xbasic syntax 'ON_DATRABSE_...()' and 'SYSTEM_EVENT_DROP()'. Testing for events becomes somewhat more troublesome though as there appears to be no readily available syntax to do this.

What I have found though is that use of a pointer in conjunction with the function 'PROPERTY_TO_STRING()' circumvents the error messages, albeit at the expense of possibly needing to decipher the cryptic response. But that's not an insurmountable problem.

So here is an example:

Dim ptr as P
ptr=SYSTEM_EVENT_DATA_GET()
'
'  Syntax such as ptr.database_exit.1 only works in the interactive panel.  So ...
'
Dim varC_EventText as C
varC_EventText = property_to_string(ptr.database_exit.1)
if varC_EventText = ""		' No event registered.
   ...
else				' Event is registered.
   ...
end if

You have to be careful using 'SYSTEM_EVENT_DROP()' too. If you try dropping an event that does not already exist you will end up again with one of those obscure Alpha5 error messages. So you have to test for it first (as per my sample code above) before dropping.

IMHO I think some tinkering by the good folk at Alpha Software would help make 'SYSTEM_EVENT_DATA_GET()' a little more developer friendly.