state_machine

StateMachine::Branch#match

Attempts to match the given object / query against the set of requirements
configured for this branch.  In addition to matching the event, from state,
and to state, this will also check whether the configured :if/:unless
conditions pass on the given object.

If a match is found, then the event/state requirements that the query
passed successfully will be returned.  Otherwise, nil is returned if there
was no match.

Query options:
* <tt>:from</tt> - One or more states being transitioned from.  If none
  are specified, then this will always match.
* <tt>:to</tt> - One or more states being transitioned to.  If none are
  specified, then this will always match.
* <tt>:on</tt> - One or more events that fired the transition.  If none
  are specified, then this will always match.
* <tt>:guard</tt> - Whether to guard matches with the if/unless
  conditionals defined for this branch.  Default is true.

== Examples

  branch = StateMachine::Branch.new(:parked => :idling, :on => :ignite)
  
  branch.match(object, :on => :ignite)  # => {:to => ..., :from => ..., :on => ...}
  branch.match(object, :on => :park)    # => nil

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