How do I pass custom action data from a Visual Studio Setup MSI to an output project via a Merge module

Question

I have a fully working Setup project within Visual Studio 2008 that takes inputs from a UI and passes them via a Custom Action to the output - this works perfectly.

Now I have to change this so that the UI is still in a setup project but that the output is within a merge module.

The current Custom Action Data looks much like the following with EditHostUrl coming from a UI dialog editbox.

/HostUrl="[EditHostUrl]" 

I now need to pass this value to the merge module and then from there use it as an input for the custom action data to the project output but there does not seem to be any documentation on how to achieve this.

To be clear Wix/InstallShield etc... are not currently options. I would also rather not embed the UI within the merge module (for reasons of separation and also it's not supported out of the box with visual studio).

Answer 1

The answer turned out to be reltively simple.

When the Merge Module is included into the Setup project it is truely merged and as such the MergeModule can read values from the parents UI variables as if they were its own. I had other difficulties making this non-apparent to begin with but when creating the modules and setup projects from scratch the values are in the same context.