Pre-transformations are defined using exactly the same syntax as transformations.
The only difference is that pre-transformations are applied very early in the load sequence - before all other pattern-based operations are applied. As such, it is highly recommended that you define appropriate transformations to normalize (and truncate!) file names before proceeding with other manipulations.
For example, suppose you load up a new project where the bulk of the code is located in "c:/dev/myworkspace/foo/bar/v3.2.1./trunk/src/".
The first step here should be to define a pre-transformation of e.g.
*/myworkspace/foo/bar/v3.2.1./trunk/src/* --> foobar/*
With this pre-transformation in place, all subsequent pattern-based rules such as excludes, merge rules, transformations, cell/code association in architecture diagrams, etc. will be insulated from the highly specific paths in the raw data and, hopefully, future-proof. Moreover, you'll see much shorter and more readable "file" names in the various places where Structure101 Studio displays fully qualified paths.
Tip:
- Structure101 Studio can usually make helpful suggestions for appropriate pre-transformations - try the Suggest button.