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alexpeachey / end_state

A State Machine implementation
MIT License
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StateMachine#can_transition? now uses Guard#allowed? instead of Guard… #32

Closed davidjbeveridge closed 8 years ago

davidjbeveridge commented 8 years ago

StateMachine#can_transition? now uses Guard#allowed? instead of Guard#will_allow?

@alexpeachey I could really use failure_messages when checking can_transition?. Thoughts?

alexpeachey commented 8 years ago

The biggest issue here and why the two methods even exist is because passed and failed are user supplied when subclassing Guard. Since we don't know what they are doing we wanted a "safe" way to just check without potentially "doing" anything. In an ideal world a guard would never change things and you could just check it any time you want but we don't live in an ideal world.

All of that being said, there is nothing that says the logic to add messages into failure_messages has to happen in the failed method. I believe that's how some guards have been built, but all the failed method is for is a place to put stuff that should happen when a guard fails, like say log it out or take some action or whatever. If you have your actual check as defined in will_allow? actually fill failure_messages then it works just fine as is.

davidjbeveridge commented 8 years ago

Fair enough.