How to check if Class Module is installed/activated?

[frabulator]

I have an add-in that uses a custom class module for manipulating charts. It works fine on most computers, but some it will not load, or (possibly) can not be found.

I start off by declaring the class at the beginning of my first module:

Public ChartClass As CClass

which works fine for the computers that recognize the module, but it throws errors on the ones that don't.

My questions are:

A) Is there another way to declare this so the error will not happen?
B) Is there a way to check to see if the module is there before declaring the ChartClass publicly?

Thanks for the help in advance.

~Frab

[Andy Pope]

You could use late binding and declare as an object. Elsewhere in you code you would still need to check for the presence of the addin in order to create a new instance of the object

Public ChartClass As Object    'CClass

As the object is now an Object, rather then a CClass, intellisense will not work.

[frabulator]

You could use late binding and declare as an object. Elsewhere in you code you would still need to check for the presence of the addin in order to create a new instance of the object

Thank you for your prompt reply, but that did not work for me. I tried doing a late binding by declaring the CClass as an Object and a Variant. Both yielded the same result, which was nothing. When going with these methods the add-in acts like the CClass Class Module doesnt exist?

I am using this to set the Object to a CClass, is this correct?

Set ChartClass = New CClass

[romperstomper]

Is all the code in the same workbook as the class module, or are you using references between projects?

[frabulator]

Is all the code in the same workbook as the class module, or are you using references between projects?

It is all contained inside the same workbook/add-in.

[Andy Pope]

If it's all within the addin why would it not work sometimes? Why would the module not be there?

Your explanation of the situation has me confused

[frabulator]

If it's all within the addin why would it not work sometimes? Why would the module not be there?

Your explanation of the situation has me confused

Me too. Thats why I brought it here.

The code runs great on (I assume) roughly 75%, but the other quarter, the code holds up and acts like the Class Module isnt even there.

[Andy Pope]

Does your code include references to other libraries that may not be present on those PCs?

[frabulator]

Does your code include references to other libraries that may not be present on those PCs?

I thought about that right before you typed it.

In the beginning of the CClass, I have the following declared:

#If VBA7 Then
    'declare virtual key event listener
    Private Declare PtrSafe Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer
#Else
    'declare virtual key event listener
    Private Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Long) As Integer
#End If

Private Declare Sub GetMem2 Lib "msvbvm60.dll" (ByVal Ptr As Long, ByRef RetVal As Integer)

The mentioned dll is part of the vb6runtime that is optional to install. If that is not found on the machine, then the code could lockup and jump out of the CClass, acting like it didnt exist.

Would I be correct in assuming this?

[Andy Pope]

If the library is not found then compile errors will appear. Some/most times the error raised is not related directly to the missing library.
You see lots of posts where the Len function reports a compile error when a library reference is missing

[romperstomper]

What are the actual error messages that you are getting?

[frabulator]

What are the actual error messages that you are getting?

Looking back at my screen shots, it looks like the first error is a compile error inside the CClass. Then other errors come after that saying that it cannot find CClass.

So, I guess that is my answer. Something inside the CClass is working for most people but not for all.