A very lightweight Finite State Machine in ObjC using blocks
Instanciate an new machine and add state transitions using blocks... basta cosi!
Note that a state is implicitly defined when a transition is added for a particular state. All transition block need to call the done() callback from within the block to finish the transition (see example below). There is no watchdog for missing done() callbacks!
Define a transition:
- (void)on:(NSString *)event transitionFromState:(NSString *)from toState:(NSString *)to usingBlock:(FSMTransitionBlock)block;Set a particular starting state:
- (BOOL)setState:(NSString *)name options:(FSMStateOptions)options;Send an event:
- (BOOL)event:(NSString *)event;Send an event with userInfo:
- (BOOL)event:(NSString *)event userInfo:(id)userInfo;Define a block to be run on entering a state:
- (void)enterState:(NSString *)name usingBlock:(FSMStateBlock)block;Define a block to be run on leaving a state:
- (void)leaveState:(NSString *)name usingBlock:(FSMStateBlock)block;Define a block to be run on cycling a state:
- (void)cycleState:(NSString *)name usingBlock:(FSMStateBlock)block;FSM *machine = [[FSM alloc]init];
[machine on:@"Power" transitionFromState:@"PoweredDown" toState:@"PoweredUp" usingBlock:^(id userInfo, FSMStateBlock done){
powerup();
done(); // !
}];
// Allow the machine to handle "Coin" event when powered up
[machine on:@"Coin" transitionFromState:@"PoweredUp" toState:@"PoweredUp" usingBlock:nil];
[machine enterState:@"PoweredDown" usingBlock:^{
shutdown();
}];
// Start the machine in state "PoweredDown"
[machine setState:@"PoweredDown" options:kFSMStateEnter];
// Now, let's power up the machine
[machine event:@"Power"];Copyright (c), 2013 Thierry Passeron
The MIT License
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