You can specify Guard conditions on Transitions using any action language. Open test_guard.mdzip to see an example of how to specify Guards on Transitions. 

You can use the properties of a context Classifier (the Classifier that is the context of a State Machine diagram) in Guard expressions as variable names. The real values of the variables will be resolved at runtime. In the example in test_guard.mdzip, the values come from the slots of the instance of the context Classifier (see the Instance diagram in the sample project). 


Test_guard Example
The Test_guard diagram sample.