only allow user to open presentation if Environ("username") matches a whitelist

  • Thread starter Thread starter nethack.addict
  • Start date Start date
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nethack.addict

This is a question for the powerpoint VBA gurus among you:

I have a presentation that I only want viewable by certain
usernames--specifically, users whose Environ("username") matches a list
that I specify.

For example, suppose that I decide only the username "john" is allowed
to view my presentation. Then the ideal sequence of events would be:
- User opens presentation
- VBA checks to see if Environ("username") = "john"
- If yes, the user is allowed to view the presentation; if no, they are
given some kind of warning and/or the presentation closes.

This solution does not need to be uncrackable, just inconvenient for
any unauthorized users that "john" might forward this presentation to.

Things I've tried so far:

- Covering the content of each slide of the presentation with a
rectangle named "blocker", asking the user to click a commandbutton on
the first page, which triggers code that deletes the "blocker" shapes
only if Environ("username") = "john"
+ problem: doesn't work if I save the file as read-only
+ problem: clicking on commandbutton on first slide seems to hang
the presentation

- Trapping the event corresponding to the opening of the presentation,
doing the username check then, and closing the file if the user isn't
on the authorized list
+ Problem: there's no built-in "auto_open" event in powerpoint. You
can work around this using an add-in, but I don't want the user to have
to install an add-in to view this presentation.

The good news is that Environ("username") returns the right data. So I
just need to figure out how to limit access to the presentation based
on this data ... would be most grateful for any expert advice!
 
You seem to have hit most of the reasons I scrapped a security feature
add-in I tried to develop a few years ago.

Have you thought of using something like SharePoint?


--
Bill Dilworth
A proud member of the Microsoft PPT MVP Team
Users helping fellow users.
http://billdilworth.mvps.org
-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
vestprog2@ Please read the PowerPoint FAQ pages.
yahoo. They answer most of our questions.
com www.pptfaq.com
..
 
Drat, I was hoping for a simple, lightweight VBA solution ... but I
guess if an MVP tells me it can't be done, it can't be done :/

Maybe the silver lining is that this approach would be really easy to
implement in Excel :)
 
LOL -- I've been known to be off on one or two things in the past. Someone
may offer a different opinion on this problem. The only other option I
could think of off the top of my head is a password to open the file and a
different one to modify. People 'on the list' are given the open password,
but not the modify one. I know, I know. The solution sucks only slightly
less than the problem. Oh well.

With excel, you gain the ability to auto_run code on an opening workbook (if
the security is set low enough), but I still don't think you can change a
read-only file.


--
Bill Dilworth
A proud member of the Microsoft PPT MVP Team
Users helping fellow users.
http://billdilworth.mvps.org
-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
vestprog2@ Please read the PowerPoint FAQ pages.
yahoo. They answer most of our questions.
com www.pptfaq.com
..
 
Maybe this is way off too but at least its something to think about!

Add a blocking shape to all slides with a with previous exit so the slides
cant be read in edit mode.

Use a modify password to make read only and save in kiosk mode to prevent
keyboard etc being used

Navigation is now only by action buttons, use vba to make .visible = false
for all buttons and a button on slide one which makes them all visible if
username = list


--
___________________
John Wilson
Microsoft Certified Office Specialist
http://www.technologytrish.co.uk/ppttipshome.html
email john AT technologytrish.co.uk
 
Drat, I was hoping for a simple, lightweight VBA solution ... but I
guess if an MVP tells me it can't be done, it can't be done :/
Click to expand...

The problem with VBA solutions is getting PPT to run the VBA; other than via an addin, three's no workable
way of getting to run code when the user opens a file.

What about getting the user to run a small VB or other EXE that then launches PPT?
 
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