I have created an Excel Workbook with a lot of VBA code for a customer. The customer will provide me with data. I will import that data into the VBA laden template, Save it as an xlsm, and deliver it to the customer. I get paid by the Workbook so I need to prevent them from trying to copy new data into the existing workbook and reusing it.
How can I somehow prevent the customer from reusing a workbook by just entering in new data on the main Worksheet, then saving as a new Workbook, and getting the use of the VBA code for free. (Alternately they could copy the file in windows then enter new data on the copied version.) I need to detect a significant change in data from the initial imported data.
The data on the main sheet is fairly static (perhaps even totally static on many known columns). I'm thinking about randomly sampling some of the cell data on import (perhaps 10 random cells, or number of rows, etc.), and storing that data somewhere. If, say, 50% of the cells change data, I could just disable (or short-circuit) the public entry points in the code...or something else?
I'd like to allow for some flexibility on the part of the customer, but prevent abuse.
Is there a better way than my general idea, above?
Where could I store that data (it should be part of the sheet, but not changeable by the customer). Perhaps a hidden sheet with password locked cells?
Is there some accepted way of doing this that I'm unaware of?
Perhaps Time-expire the functionality in your code
So thank you for this question. Thank you for setting a bounty. It is a very interesting question given your desire to monetise the VBA code, as a VBA programmer I generally resign myself to not being able to monetise VBA code. It is good that you insist and I will contribute an attempt at an answer.
Firstly, let me join the chorus of answers that say VBA is easily hacked. The password protection can be broken. I would join the chorus of respondents who say you should pick a compiled language as the vessel for your code. Why not try C# or VB.NET housed in a Visual Studio Tools For Office (VSTO) .NET assembly?
VSTO will associate a compiled assembly with a workbook. This mechanism is worth knowing because if you insist on VBA we can use the same mechanism (see later). Each workbook has a CustomDocumentProperties collection where one can set custom properties (it says Document not Spreadsheet because the same can be found in Word so Document is the generalised case).
Excel will look at the workbook's CustomDocumentProperties collection and search for "_AssemblyName" and "_AssemblyLocation"; if _AssemblyName is an asterisk then it knows it needs to load a .NET/VSTO assembly, the _AssemblyLocation provides a lookup to the file to load (you'll have to dig in on this, I forget the details). Reference
Anyway, I'm reminded of VSTO CustomDocumentProperties mechanism because if you insist on using VBA then I suggest storing a value in the CustomDocumentProperties collection that helps you time expire the functionality of your code. Note do not use the BuiltInDocumentProperties("Creation Date") because it is easily identifiable; instead use a codeword, say "BlackHawk". Here is some sample code.
Sub WriteProperty()
ThisWorkbook.BuiltinDocumentProperties("Creation Date") = CDate("13/10/2016 19:15:22")
If IsEmpty(CustomDocumentPropertiesItemOERN(ThisWorkbook, "BlackHawk")) Then
Call ThisWorkbook.CustomDocumentProperties.Add("BlackHawk", False, MsoDocProperties.msoPropertyTypeDate, Now())
End If
End Sub
Function CustomDocumentPropertiesItemOERN(ByVal wb As Excel.Workbook, ByVal vKey As Variant)
On Error Resume Next
CustomDocumentPropertiesItemOERN = wb.CustomDocumentProperties.Item(vKey)
End Function
Sub ReadProperty()
Debug.Print "ThisWorkbook.BuiltinDocumentProperties(""Creation Date""):=" & ThisWorkbook.BuiltinDocumentProperties("Creation Date")
Debug.Print "CustomDocumentPropertiesItemOERN(ThisWorkbook, ""BlackHawk""):=" & CustomDocumentPropertiesItemOERN(ThisWorkbook, "BlackHawk")
End Sub
So you could set CustomDocumentProperty "BlackHawk" to the workbook's initial creation time and then allow the client to use the code for 24 hours, or even 48 hours (careful with weekends, create Friday work through to Tuesday) and then afterwards the code can refuse to operate and instead throw a message saying pay LimaNightHawk more money!
P.S. Good luck with your revenue model.
P.P.S. I read your profile, thanks for your military service.
Whatever you do it will be feasible to crack it (VBA code is easy to crack). However:
there is the contract so... that's not legal for them to do it
you can put part of the code on a FTP server and control physically what is being executed
Very nices ideas here though
Compile Excel file to EXE. Google for that.
Concern 1 seems to be basic re-use of the file. You could create a sub in the ThisWorkbook module to destroy code located in other modules in the event that save-as is selected.
Concern 2 seems to be someone hacking your password protection. A similar tactic could be employed such as using "opening the developer window" as your event instead of save as.
I have experimented with save events to log user entries with great success using the ThisWorkbook module. I am not certain how/if one could detect if the developer tab is opened.
Here's what I've done. Perhaps there is a entirely better approach, or there are tweeks to the below that will make it better:
From the VBA Tools menu > VBAProject Properties > Protection (tab), I Locked the project for viewing with a password.
I created a new "License" sheet.
This sheet is hidden from the user. If you hide the sheet via code like this:
Me.Visible = xlSheetVeryHidden
then then sheet cannot be un-hidden by the user (it requires running vba code to unhide).
On initial import I sample:
Number of imported rows
x number of randomly selected cells *from the columns I know won't/shouldn't change. (There are columns they are allowed to change freely.)
I store these on the "License" sheet in Address / Value pairs.
When the workbook is opened, the Workbook_Open event fires and then does a quick comparison of the current number of rows, and the current values for the addresses stored on the "License" sheet. I then do a percentage calculation: If the rows are more than x% different, or the number of changed values is more that y% then I
Sheets(1).Protect LOCKOUT_PASSWORD
Application.Calculation = xlCalculationManual
Application.EnableEvents = False
There is also a method for unlocking the sheets if necessary.
This might be too simple of an answer, but sometimes we fail to think of the simplest solutions:
Why don't you simply provide the customer with only a copy of the output? You could run their data through your macro-enabled workbook, copy the output sheet into a new workbook, and then break all links so that there's no formulas, updating, or ties to your workbook.
I would create another workbook that contains the code and then reference the customers wb from that one.
Related
Is there a more secure way of protecting excel sheets without embedding the password in the vba code with sheet.Protect code? Required functionality is to copy excel sheets with a macro and retain protection so formulas remain hidden.
Two template sheets have hidden formulas. Copy protection on these sheets allow users to do everything except Edit objects and Edit scenarios.
The sheets need grouping functionality which requires VBA code (added to workbook_Open) to set sheet.Protect UserInterfaceOnly:=True for any sheets with ProtectedContents = True, and .EnableOutlining:=True. All other Protect attributes are set to True in the code except DrawingObjects and Scenarios.
Copying either protected sheet with the excel interface maintains protection on the copy. Copying a sheet in VBA code results in a new sheet with no protection.
My concern is despite protecting the code with a secure password in excel 2010 the code and the embedded password is easily displayed by opening the file in other software. Is there a more secure way of protecting the sheets without embedding the password in the code?
Reference: Retaining Existing Excel Worksheet Protection When Enabling Grouping
By nature, Excel security is not particularly strong. The protection functions exists mainly to prevent lay users from making inadvertent mistakes. However any determined and capable person won't take too long to hack/crack any security you put in place. As an example of how easy it is, take a look at one of the most up-voted questions here:
Is there a way to crack the password on an Excel VBA Project?
Therefore even if you protect the actual VBA project, it's relatively simple to get around this.
In your specific case, you're using a Worksheet_Open event to apply protection - however this is the easiest thing in the world for anyone to bypass, by simply opening the workbook in question via a sub in another workbook, after having turned events off. You may also have some users whose macro security settings are not automatically enabled, and if they dismiss the "Enable Macros?" prompt when they open your workbook, the Open event will never fire.
If you're happy with this level of security - and happy that your workbook won't be the target of hacks from determined users - then you needn't worry too much about storing the protection password in the code itself. However there are a couple of simple ways you can at least make it less visible (in case a user accidentally presses Alt+F11, or an error causes the VBE to open:
Instead of typing the password in the code in plain text, use the Chr() function. So instead of:
Dim pw As String
pw = "hello!"
... you could write:
Dim pw As String
pw = Chr(104) & Chr(101) & Chr(108) & Chr(108) & Chr(111) & Chr(33)
Another way is to store the password within a cell (for example A1) of another sheet whose visibility is set to xlVeryHidden, and reference Sheets("HiddenSheetName").Cells(1,1).Value.
As I said - these are not perfect ways of securing sensitive data and formulæ: however if your goal is simply to stop casual users from making a mistake, or poking around where they shouldn't, then they will do the job.
Additional: for multiple instances requiring the password, I use something like this myself:
Function pw() As String
pw = Chr(104) & Chr(101) & Chr(108) & Chr(108) & Chr(111) & Chr(33)
End Function
Then call it as needed. You can even name the function something else slightly cryptic, not "pw" etc.
I have some User Defined Functions in an Excel book. I used them for a while but, after a while, I deleted the calls to these functions from the cells because I found a better way to accomplish the same task (I didn't delete the function definition itself in the VBA editor). So, these functions are no longer being called neither in the book nor from any VBA code, I checked it using a search to be 100% sure.
Now I'm doing some review on my code and I noticed something strange: in a Sub procedure in the same workbook (which has nothing to do with these functions) I call Application.CalculateFullRebuild. When this happens those UDF get called, I can see it by setting a break point inside the UDF.
I'd like to know why is it happening and what can be done to avoid it, as it is slowing that Sub unnecessarily.
Thanks!
Application.CalculateFullRebuild MSDN reference has this to say:
The CalculateFullRebuild method is similar to re-entering all formulas. ... [When run] a full calculation of the data in all open workbooks is performed and the dependencies are rebuilt.
Further MSDN reference states:
Causes Excel to rebuild the dependency tree and the calculation chain
This means that any UDFs in the module code or sheet code will be recalculated because Excel is rebuilding and testing functions for dependency and use in the calculation chain.
If you are looking for a way to simply manually calculate the existing formulas in the sheet via your Sub, you can use 'Application.Calculate' (MSDN):
Application.Calculate 'for all open Sheets
Sheets("Name of Sheet").Calculate 'Specific Sheet
Sheets("Name of Sheet").Range("Name of Range").Calculate 'Specific Range
The system is working as it should. Consider:
Function qwerty() As String
qwerty = "qwerty"
MsgBox "XX"
End Function
It is non-Volatile and has no arguments. It will be calculated at the time it is entered in a worksheet cell. Application.Calculate may cause it to be calculated once, however:
Sub ytrewq()
Application.CalculateFullRebuild
End Sub
will cause the UDF to be re-calculated each time ytrewq is run.
To the moment my approach has been commenting all the code inside the UDF with two objectives: increasing speed on one side and checking if any side effect happened on the other side. To the moment, I have not observed any side effect, so more to the point that they are not being used anywhere.
Right now the application I'm developing is working quite well, but I'll try the solutions you're proposing just out of curiosity. By bets are on either it's being used somewhere hidden and forgoten or simply that I have some rubbish inide the workbook structure that is not getting cleaned.
Thanks!
Update
Tried again the next day and those UDF are no longer being called. Thus, I'll have to assume that something odd was going on with Excel that went away when I restarted it.
Anyway, thanks a lot for the Application.Caller thing, which I didn't know about.
CONTEXT: I have created an Excel Add-In in which there is a worksheet named "Mother". When the user clicks a button from any workbook in which the Add-In is installed, I would like the worksheet "Mother" to be copied inside its same workbook and being renamed. In code:
ThisWorkbook.Sheets("Mother").Copy After:=ThisWorkbook.Sheets(ThisWorkbook.Sheets.Count)
WHAT I EXPECT: being the line of code above placed into the .xlam code, I know that ThisWorkbook refers to the Add-In and this is observable through a watcher as well:
So, I expect that a copy of "Mother" will be added to the workbook, at the end.
WHAT HAPPENS: the method simply fails, returning the error Copy Method of Worksheet class failed.
WHAT I HAVE TRIED: By simply looking for the name of the error online I have figured out that, apparently, I cannot copy a hidden worksheet and that's why the method fails. So I have tried:
1) To change the visibility with ThisWorkbook.Sheets("Mother").Visible = True... No success;
2) To activate the workbook before/after to change the visibility, so ThisWorkbook.Activate... No success.
I'm not being able to find much documentation online about this, so I'm almost wondering if it's actually possible to edit/show the workbook.xlam, something that I would really need to do for my project.
A BIT MORE OF CONTEXT: The reason why I need to both add the worksheet and show it to the user is that the Add-In, which basically consists in a custom function =myFunction(), needs to be fed by user-inputs for make its calculus.
In particular, neither I can write the data in the sheet before to distribute the Add-In (because I don't know the user inputs in advance), nor I can prepare a user-form where to insert the data and show it at running-time (because the user-inputs are usually a big amount of data that can be copied-pasted easily into an Excel spreadsheet, but not inserted manually into a form nor in the function parameters themselves). So:
MY QUESTION: Is it possible to copy (duplicate) a worksheet within a .xlma workbook and activate it after to allow the user data insertion? If yes, where am I being wrong on the above?
Looks like this link would help: http://forums.techguy.org/business-applications/1120165-add-extra-sheet-xlam-file.html.
The operation cannot be performed on add-in workbook, hence you just need to set it as "not add in":
ThisWorkbook.IsAddIn = False
'your copy operation
This Workbook.IsAddIn = True
I have three modules (standard module, not class module) in my Excel VBA project. One of those was added by right-clicking the VBAProject and insert a module. Two of them were added by executing "modules.add"; I guess modules means module sheets, right? So, my questions are:
1. What does a module mean in VBA?
2. How can I know which module is created while adding a modulesheet?
3. Why when I add a worksheet,there isn't a module appear?
A module is simply a place to put your code. You can just see it as a sheet of paper where you can write something.
In Excel you can put your code in a module, or "behind" a worksheet (what you call a modulesheet). A module is always added manually BY YOU. The "modulesheet" is part of a sheet and thus added or deleted BY EXCEL automatically whenever you create or remove a sheet
When you put some code and variables in a module, its instantly available from all worksheets within your workbook, dependinv on how you declare your variables, subs and functions (private/public)
Usually when one put code behind a worksheet, its because this code is only meant to be called from that particular worksheet and only perform operations on it. I personnaly never work on worksheet level for several reasons:
if you delete your sheet, you lose all code that was behind it.
if you export a sheet, you export the code as well.
if you duplicate a sheet, you duplicate the code as well.
if you want to run the code behind a particular worksheet from another place, you have to fully qualify your calls and variables, which is a horrid solution and also plain boring
My advice is: IN EXCEL, never work on sheet level, uses modules, and if you reach a decent amount of code, organise it in logical groups using multiple modules
RE 1: A module is like a singleton class which has already been initialized, so to speak. In other words a module's code (public properties/variables, public methods, etc) is always available, one does not have to inherit an instance before tries to use it, however, all the data in a module's properties/variables are common "application-wide"
RE 2: It is "sheet module", not "module sheet". This means nothing but the newly added sheet has a module with it when you add it. There's no difference between having this, or adding a module to the sheet later. You can open the code editor window and see modules, classes, etc by pressing ALT+F11
RE 3: By default no VBA code is added to any new sheet because of security reasons. If a Workbook has macro (VBA code) in it, extra attention is required so by default a workbook is not a VBA(macro) workbook.Last but not least, please note that there's no difference between one module or another. The way you create a module does not affect the way modules behave, and there's only one "type of module" (as well as one "type of class module") in Office applications (Excel, Word, etc)
for number 2:
Sub moduleAdd()
Modules.Add
'Modules.Add
qq = Modules.Count
MsgBox "total added module by code = " & qq
For ii = 1 To qq
Set modu = Modules(ii)
If ii = qq Then MsgBox "Newly added module = " & modu.Name
Next
End Sub
We receive Excel files daily from our field offices which I have to clean and re-format (about 110 columns and 500 rows-worth) using VBA.
I need to save my VBA as a macro so we can use it to clean up all the workbook we receive by running the macro and saving the edited sheet as a new worksheet by getting the name from UserForm Combobox items.
Where exactly should I store the VBA snippets? I mean when I open the Visual Basic panel, I have these three options:
Running The Code From Microsoft Excel Object :Sheets1(Sheet1)
Running the Code From An Inserted Module
Running the Code From User Form
If I am supposed to use options 1 or 2, how can I call the UserForm for saving the sheet?
I Recomend you to use modules (Option B)
Option C goes with option B, ill explain, you can create a sub in a module in option B, then you can do:
UserForm1.show
In Option B I would writte this code, but before trying this i recomend you to understand a bit more of vba
sub ClearWBs()
'opening workbook
Workbooks.Open Filename:="c:\book1.xls"
'your code
'your code
'below code for saving and closing the workbook
Workbooks("book1.xls").Activate
ActiveWorkbook.Save
ActiveWorkbook.Close
end sub
Use Module:
If your VBA code focusses on data summarization and manipulation I suggest you use a Module.(example is what you have described in your question).
Use Form:
If what you wan't to do requires a GUI(Graphical User Interface) then you'll have to resort to Form where you can design your GUI. (example is if you have many fields that the user needs to fill-up with distinct values in which you provide the choices)
Use Excel Object:
If what you wan't to do has something to do with events happening on Worksheet and/or Workbook, like for example whenever you add sheet the macro runs, or when you open or close the workbook the macro runs then you will have to write the macro in the Excel Object.
This is basically what i have in mind, hope this helps.
If you receive files that do not contain VBA and you need to apply the same code on those files all the time then I propose that you either save that code in your personal workbook.
You can see how to do that here: http://office.microsoft.com/en-ca/excel-help/copy-your-macros-to-a-personal-macro-workbook-HA102174076.aspx
This is nice because you can also tie it to keyboard shortcut or just have it always ready for you to use.
The disadvantage is that it will only be set up per user session per computer. What you can do is have that code all set up in a module and then import it into your personal workbook if you change session or if someone else has to do it.
Once it's done, you will not have to include the module in your files your receive again.