I have a model folder which contains several shapefile, but only one named oil.shp. Is there a way to automatically set the default value for the Add Oil Layer based on the model folder and the shapefile's name? It can be done by using os.path.join(model_folder, 'oil.shp') if I don't set Add Oil Layer as one parameter. However, I want to leave the parameter there in case someone else wants to play around with another oil.shp as needed. The Script Properties comes from the Script tool.
I am using ArcGIS Desktop 10.3.1 Advanced License.