Wix and file search in installdir - windows

Question

I try to create installer for postgresql zip with binaries. On first installation I run initdb and it initializes postgresql cluster and create data folder. On removing my app this data directory doesn't remove. On next installation in the same dir initdb fails because directory is not empty.
I want to search file [INSTALLFOLDER]/PostgreSql/postgresql.conf and if it exists than ignore initdb custom action.
I can't use DirectorySearch because it is before INSTALLFOLDER exists. I read that there is a way to call directory search via custom action but I can't find any info about it.
How I can check that postgresql cluster has initialized already and skip init db custom action.

Answer 1

One solution would be to create an immediate execution custom action to check for the existence of the file. If so, set a property and use that property in a condition in your initialization custom action.
In the C# managed custom action example below, it takes the value of "SOMEPROPERTY" and if the corresponding directory exists, sets the property RUNINITDB=1. You could then use RUNINITDB in a condition in your initialization custom action. If the property RUNINITDB exists, then run your custom action.
[CustomAction]
public static ActionResult CheckInitDb(Session session)
{
session.Log("Begin CheckInitDb");
string dir = session["SOMEPROPERTY"]; //or you could figure this out programmatically
if(!Directory.Exists(dir))
{
session["RUNINITDB"] = "1";
session.Log("Setting RUNINITDB bit.");
}
return ActionResult.Success;
}
To create the custom action project above, create a new Visual Studio project and under the Windows Installer XML templates, select C# Custom Action Project.
To reference the custom action in your installer XML source code, assuming the custom action is in a dll named InstallHelper.CA.dll, you may have something similar to the code below. Note the custom action CallToRunInitDB will only run if the property RUNINITDB is set.
<Binary Id="InstallHelper" SourceFile="InstallHelper.CA.dll"/>
<CustomAction Id="CheckInitDb" BinaryKey="InstallHelper" DllEntry="CheckInitDb" Execute="immediate" Return="check"/>
<InstallExecuteSequence>
<Custom Action="CheckInitDb" Before="InstallInitialize">NOT (REMOVE ~= "ALL")</Custom>
<Custom Action="YourCallToRunInitDB" After="InstallInitialize">RUNINITDB</Custom>
</InstallExecuteSequence>
If you are unfamiliar with WiX managed custom actions you may be able to find some other sample code on SO: https://stackoverflow.com/search?q=wix+managed+custom+action