Encoding a Custom Action Type field is relatively simple. You just need to use the different values as flags, and use that as a number. Decoding is a completely different matter. There are several conflicting rules, and various flags have the same value. To make matters more complex, the
msidbCustomActionTypeBinaryData flag has a value of
0, making it impossible to use as a flag. In this very simple project, I have encoded the rules to decode.
Before reading this article, you should have a good grasp on what an MSI database is, and how to edit it using Orca. You will not be doing that with this program, but not being able to do that renders the contents of this article somewhat useless.
Using the Code
The rules for encoding are very simple, and they are as follows:
Action Types with values lower than 7 imply the use of
msidbCustomActionTypeBinaryData. All others are not using it.
msidbCustomActionTypeInScript is present, the values 0x100 and 0x200 are
msidbCustomActionTypeCommit. If it's not present, those values represent
msidbCustomActionTypeOncePerProcess. Also, the value
msidbCustomActionTypeClientRepeat should never be selected at the same time as
The first 7 values are exclusive. That is, an action may be
msidbCustomActionTypeInstall but none of them at the same time. This basically amounts to values 1 through 7 not being flags, but textual values.
Points of Interest
The Type column was obviously grown organically, and as such it doesn't make sense as a true flag. This makes sense historically, but it makes decoding much more difficult than what it should be. I hope my little program helps with that confusion.
- 18th September, 2008: Initial post