first time asking something here, so I'll apologize beforehand in case I do anything I shouldn't do.
I'm working on a workbook and there are some information in it that shouldn't be available to everyone else, save a few users.
While doing some testing around I've found that it was possible to use another instance of Excel, i.e. another workbook, to access that information (in this case, using VBA).
What I want to know is: is it possible to block another instance of Excel or another workbook from accessing this workbook with the information I want to protect?
The point of this sheet in working on is to be used as a 'database' of sorts for performance feedback of other employees. They fill a form with their self evaluation and then their manager also fill it, evaluating them. All this is stored in a sheet, which is hidden (veryhidden, to be more specific). Using a simple login system, I was able to enable access to this sheet to only one user (one with admin privileges), but assuming someone knows the existence of that sheet, it would be perfectly possible for them to, for example, just copy everything from that sheet to a blank sheet in a new workbook.
Ultimately, what I'm trying to achieve is some kind of restriction in this workbook, allowing only it's own subs and functions to work on it
Thanks in advance
EDIT: Added some info. Hope that helped clarify my problem
The only way to achieve this is encryption. As far as I know Excel only supports one form of encryption, full workbook encryption. In that case there is a password to open the workbook, a user either has access to the full workbook or none at all.
Any other form of encryption in Excel, protected cells, passwords on macros, etc. can all be bypassed easily by a knowledgable user.
However, you could achieve this using either an external database server or implementing your own encryption scheme in the workbook.
There is some information here on howto access the Windows CryptoAPI from VBA.
Related
Would like to check the value from my master file and copy the data comments from different excel files.
In my master I have a column contained all the user name. Would like to copy the address of the user from different excel file. Would like to open the workbook and look through is the user name in the workbook, if not then then exit and open another workbook.
How should I complete the flow ?
Unfortunately StackOverflow is not a free coding service. Our goal is to help you understand how your code works and engage the community with questions that will also help others in the future. Try running some of the code on your own and see what you can come up with. There are hundreds of sources online, one of my favorite being "Excel Easy", a website that breaks down VBA coding to its simplest form. Check it out and then after you've given it a go yourself feel free to ask any specific question about your code!
END GAME: A user saved Workbook opens and mirrors code from a target file.
I am trying to create a simple VBA application that has an Excel front-end and an Access back-end. There will be multiple users who would have the option to save the front-end Excel piece anywhere they desire.
I would like to know the most efficient way to be able to update macros in all user instances when I need to push updates.
Essentially, I would like to mirror code from a "global" file on Workbook_open. In the past I did actually set code to open a separate workbook and run code (dim x as workbook, open, app.runmacro and etc.), But I think that is not really the most efficient way to do it.
Four possible solutions pop to mind for this (other than your option of having an intermediary workbook), there are likely others:
Treat the Workbook as purely an interface, and move the code to the
Access database and have it accept the Workbook as a parameter if
needed. The advantage would be the code could be maintained in one
place (Access), but it would have two main disadvantages. Each user
would need to have Access installed in order for it to instantiate
the application to call methods on, and it would lock in your
"interface" - that is, changes to how it calls Access macros would
still require Workbook updates.
Create a canonical Workbook and have the user Workbook version check
against the canonical Workbook when opened. If the version is
different, open the new one, move all of the data to it, delete the
old one, and save the new copy to the same filename as the old one.
The main disadvantage of this method would be ensuring that old code doesn't run might be difficult, as you would need
to take measures to prevent situations where the user could abort
the update process and still have a working copy of the old code.
Automate the VBE (see this answer for implementation details -
there are numerous resources on how to do this). Depending on how
you wanted to do this, you could either store the current modules as
files and import them, or store the code in the database itself and
query for it. The main disadvantages of this method are that the
VBE can be fickle about changing code that is actually running. I'm
not sure that I'd trust it to change it's own implementation. You
would also need to allow access to the VBE in each user's security
settings, which may pose a security threat.
Store the location of the Workbooks themselves in the database, then
push out updated copies with external code. The Workbook would
report it's filepath when opened, and if it wasn't already recorded
in the database, check to see if it was the most current version,
and then write a record for itself. This has the disadvantage of
only being able to inform the user that they don't have the current
version if they (for example) move the Workbook in Explorer and
don't open it until after your push.
Note that these are all "pull" type as opposed to "push" type solutions with the exception of the last one. Regardless of the method you use for version checking, any push solution is going to share the disadvantage of number 4 - there is no reliable way to make sure that a push catches all the invalidated versions.
I have a spreadsheet that I have password protected from allowing users to edit.
I would also like to password protect ANY and ALL actions related to Macros within this spreadsheet. I don't want anyone to be able to create a new macro in this sheet, run an old macro in this sheet, or even run a macro stored in another place on the computer.
Is this possible?
This is not possible in excel. There may be some system adminy thing you can do with Group Policies to force macro security, but that would affect all excel spreadsheets for that user, and not just the specific one you want. The whole idea is Excel is a document, not an application. Documents by design are reproduced and shared, and what the end user does with it is his/her perogative.
I have a macro-enabled form that is intended to allow of a team of data-entry staff to record their daily efforts by transaction number. As forms go, it's pretty basic. However, I need to write a macro for a button that will let each person submit their records to a master sheet at the end of their shifts. I need to copy the range data and paste to a master workbook, with the person's name and the date being added to the individual rows.
I'm not sure how to facilitate the copy and paste to a closed workbook, or how to prevent problems with multiple people submitting to the form at the same time. Can anyone offer any suggestions please?
Make it update a database and then generate the report at the end of the day from that. I would also recommend that it inserts into the database each time the user inputs a record so that in the case of a power outage, all of their work from the day doesn't get lost. This will likely reduce the amount of concurrency issues too as the users will be periodically adding records instead of many records at the same time. Search 'VBA DAO' or 'VBA ADODB' to find examples on how to connect to a database with VBA.
You can do this simply by opening the workbook, inserting, and then closing the workbook. There is no simple way to insert into a closed workbook. Note, you could keep things hidden if you're trying to hide things from the user.
Add a reference to the "Microsoft Scripting Runtime" to get access to the filesystem and then use a simple file semaphore to control access to the common workbook.
Regarding the closed workbook, you use Application.Workbooks.Open(...) and .Close
Primary Choice would be to send the items to a database. Since thats already ruled out, I would suggest you write the data to a plain old .csv file. This will be easier to implement, and will not be limited by excel row limits.
How can I cripple an excel document after a certain date? I want it to become unusable after, say, 12/31/2009.
I was thinking about putting one of those Must Enable Macros things in there that hides all the sheets on close and leaves one tab that says you must enable macros. Then having an on open macro that unhides all those tabs, but also will close itself if after a certain date. This has a few drawbacks in that someone could just enter in the macro code (without macros enabled) and change the expiration date... or even just change their system time. Any thoughts about good ways to do it? Is my method pretty much as good as you can get? or are there better ways out there?
Thanks.
You might want to have a look at Microsoft's Information Rights Management (IRM) technology. IRM lets you control which users are permitted to read, edit, print etc the content of a document. It is also possible to specify an expiration date.
IRM requires you to either have an ActiveDirectory infrastructure with a domain controller or you may use the IRM service hosted by Microsoft.
For further details check out Controlling workbook access in Excel with Information Rights Management.
Dan, I am not sure of the purpose you are trying to lock the excel sheet. However if you write the macro then you can password protect the VBA code so that no changes are made to the code.
Having said so, there is still a possibility to have workarounds and access the excel file; no method can be foolproof.
Cheers...