Set installation variable and create it if it does not exist

[dozminkowski]

generateScript method called twice for the same ProgramNodeContribution

In general, the code should be able to handle multiple calls to the generateScript method. It can be called when program is saved, or typically when the program is played. At play instance, it could happen, if the user double-taps (debounce) on the Play button. Note: generateScript is only called, when all nodes in a program context return true on their respective isDefined calls.

Ok, so I didn’t realize, that there is something going on backstage. “generateScript” is called also when program is run. That is great. Now I can be sure, that my variables will be set. My fears were unfounded.

Therefore my case is closed.