Chapter 3. Putting Properties and AppSearch to Work

WiX uses variables, called properties, to store data during the course of the installation. It's a temporary storage, so it won't persist once the installation is complete. However, it's the only way to pass information from one action during the install to another. For example, to collect a username and password from the end user you'll need to store them in properties. Then, you might pass them to another part of the install, use them in an outside executable or assembly, or save them to the Registry. You can also use properties in conditional statements that can alter the flow of the install or stop it if some piece of data isn't right.

In this chapter, you will learn:

• The syntax for declaring and setting properties

• How to reference properties in other parts of your markup

• The built-in properties that Windows Installer sets for you

• What AppSearch is and how to use it to search the end user's computer for installed components, Registry keys...