Licensing Access apps

[Guest]

Any clever ideas on licensing/enforcing concurrent users for Access apps I
distribute? How about this:

Have a table in the BE that has a LicenseID field (or, better yet, embed the
license in a custom DB property)
Have the number of users for this license embedded in the license and
extractable via VBA.
Have a "logged on" field in my users table (not using Access security, but a
Users table with an encryption routine for the password field).
Update this field to True each time a user logs on.
Update this field to False each time a user logs off.
Deny access if the user is already logged on.
Deny access if the number of users logged on equals or exceeds the license
count.
Provide an administrative tool to "unlock" users.

Pitfalls? Better ideas?

 

[Alex Dybenko]

Hi,
difficult to say without knowing your application. in general looks ok, but
be aware that user can leave application without logging off, so you have to
reset "logged on" field in this case somehow

 

[Guest]

The code to log off would be contained within the code on my Quit button. The
only times this could be bypassed is when a user closed Access using the
Close button in the Control Box (something a user will try only once!) or an
unexpected system shutdown or network interruption.

Since the only part that is running is the front end (obviously not a
client-server application), it seems to me that if a user lost his
connection, the next time the issue could be resolve is when he logs on
again. However, I cannot simply assume that a user's second logon is due to a
lost connection; otherwise, what is there to prevent many users using the
same ID? It seems like it would be best to just have a field in the users
table that can be reset by users having access to the form that contains the
field.

That's the administrative "unlock" field I was considering; a manual reset
of the LoggedOn field in the users table via a limited-access form.

 

[Alex Dybenko]

The code to log off would be contained within the code on my Quit button.
The
only times this could be bypassed is when a user closed Access using the
Close button in the Control Box (something a user will try only once!) or
an
unexpected system shutdown or network interruption.

you can also handle "user closed Access using the Close button in the
Control Box" if you use a hidden form (or some switchboard form)unload event
to run log off code

 

[Guest]

I hadn't thought of using the unload event. Thanks.