uml-state-machine/lib/Machine.js

UML state machine in Javascript.

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.Machine = Machine;

var _defineProperty2 = _interopRequireDefault(require("@babel/runtime/helpers/defineProperty"));

var _lodash = _interopRequireDefault(require("lodash"));

var _State = require("./State");

function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); if (enumerableOnly) symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; }); keys.push.apply(keys, symbols); } return keys; }

function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; if (i % 2) { ownKeys(Object(source), true).forEach(function (key) { (0, _defineProperty2["default"])(target, key, source[key]); }); } else if (Object.getOwnPropertyDescriptors) { Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)); } else { ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } } return target; }

function Machine(_ref) {
  var definition = _ref.definition,
      actioner = _ref.actioner,
      observers = _ref.observers;
  observers = _objectSpread({
    onEntry: _lodash["default"].noop,
    onExit: _lodash["default"].noop,
    onTransitionBegin: _lodash["default"].noop,
    onTransitionEnd: _lodash["default"].noop
  }, observers);

  var _stateMap = (0, _State.buildStateMap)(definition);

  var currentState = getRootState();
  var previousState = null;
  var nextState = null;

  function getRootState() {
    return _stateMap.get("Root");
  }

  function enterInitialState() {
    var initialStateName = (0, _State.findInitialState)(definition.state);
    (0, _State.walkOnEntry)(machine, getRootState(), _stateMap.get(initialStateName));
    setStateCurrent(initialStateName);
  }

  function getCurrentState() {
    return currentState;
  }

  function setStateCurrent(stateName) {
    currentState = _stateMap.get(stateName);

    if (!currentState) {
      throw {
        name: "RunTime",
        message: "invalid state name",
        "function": "setStateCurrent",
        details: stateName
      };
    }
  }

  function setStateNext(stateName) {
    nextState = stateName;
  }

  function addEventHandlers(machine, events) {
    return events.reduce(function (machine, event) {
      var eventId = event;

      machine[eventId] = function (payload) {
        var currentState = getCurrentState();

        if (currentState[eventId]) {
          currentState[eventId](machine, payload);
        } else {
          throw {
            name: "Internal",
            eventId: eventId,
            state: currentState.name(),
            details: currentState
          };
        }
      };

      return machine;
    }, machine);
  }

  var machine = {
    actioner: actioner,
    observers: observers,
    stateMap: function stateMap() {
      return _stateMap;
    },
    enterInitialState: enterInitialState,
    setStateCurrent: setStateCurrent,
    getStateCurrent: function getStateCurrent() {
      return currentState;
    },
    getStatePrevious: function getStatePrevious() {
      return previousState;
    },
    setStatePrevious: function setStatePrevious(state) {
      previousState = state;
    },
    getStateNext: function getStateNext() {
      return nextState;
    },
    setStateNext: setStateNext,
    setStatePreviousFromCurrent: function setStatePreviousFromCurrent() {
      previousState = currentState;
      return previousState;
    }
  };
  machine = addEventHandlers(machine, definition.events);
  return machine;
}