If the above mentioned flag is set to "No" ( in the Releases=>Build tab), installshield drops directories that are unused in the project. However, if a directory( eg: MY_XML_DIR) is set in the Directory table and is ONLY used to pass value (of MY_XML_DIR) to a helper dll (launched by Installshield project), then [MY_XML_DIR] basically contains an empty string ( as it is not set at run time ). This looks like a bug in Installshield. Please confirm.
my understanding is that it determines a directory to be unused when there are no components associated with it and will remove it from the project at build time. If you need an empty directory to exist, then associate a component with that directory.
In this particular use case, I just need the directory value to be passed on to the DLL that does the actual creation of the directory and its contents. As you suggested I can create a Component without any files and it might work - However, it sounds more like a hack. To me, a directory variable is "In Use" if it is reffered anywhere in the .ism file. Anway, my 2 cents.
if you just need a value, and not the creation of a directory by the installer, you should just use a Property instead of a Directory entry.
if you need the property to reflect a relative path to another specified directory you can set the property value to include that directory value. (i.e.: [INSTALLDIR]\mypath).
