Determining Template Data Language by a File Extension
As with IntelliJ IDEA 8.1, you can open the Settings Dialog and select Template Data Languages to specify what language should be applied to a single template, or an entire folder containing template files. IntelliJ IDEA Velocity integration is also capable of determining the language by a double file extension (e.g. foo.java.vm or bar.css.ft).
In the upcoming EAP for IntelliJ IDEA 8.1.1 you will find another way of mapping files to various template languages: open the Settings dialog, select File Types, and click Add or Edit under Registered Patterns.