# What happens when a JSF Facet is installed?

When a JSF Facet is installed, the following occurs:

- The user specified JSF Libraries are added to the build classpath if they are not deployed or, they are added as J2EE Module Dependencies which allows them to be added to the build classpath and deployed at module publish time
- The project's Web Deployment Descriptor (web.xml) is updated ensuring that the Faces Servlet is present along with the user's specification for:
  - Faces Servlet Name
  - Faces Servlet URL Mappings
  - Context Params for application configuration file
- An empty Faces configuration file using the name and location specified by the user is created. If a file with that name already exists at that location, this step is skipped.

An implementation JSF Library must be specified so that the "Run on Server" of a JSF JSP page is possible.

JSF Facets
What happens when a JSF Facet is un-installed?