fsm-state-manager/dist/fsm-state-manager.js

A Flow FSM using a finite state machine pattern

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.StateManagerFSM = void 0;
var subscription_manager_1 = require("./services/subscription-manager");
var StateManagerFSM = /** @class */ (function () {
    function StateManagerFSM(transitionRules, options) {
        if (options === void 0) { options = {}; }
        this.stateData = { state: '', appliedData: [] };
        this.options = { devMode: false, logTransitions: false, subscriptionMode: false };
        this.transitionRules = transitionRules;
        this.options = options;
        this.subscriptionManager = new subscription_manager_1.SubscriptionManager();
        if (!this.options.subscriptionMode) {
            this.subscribe = (function () {
                throw new Error('Subscription mode is disabled. ' +
                    'Turn on `subscriptionMode: true` in options, for using .subscribe().');
            });
        }
    }
    StateManagerFSM.prototype.setStateData = function (currentStateData) {
        this.stateData = currentStateData;
        if (this.options.subscriptionMode) {
            this.subscriptionManager.notify(currentStateData.state, currentStateData);
        }
    };
    StateManagerFSM.prototype.getStateData = function () {
        return this.stateData;
    };
    StateManagerFSM.prototype.transition = function (event, appliedData) {
        if (!this.isInitialized()) {
            throw new Error('[FSM Error] Initial state not set. Use setStateData() first.');
        }
        var rule = this.transitionRules[this.stateData.state][event];
        if (!rule)
            return this.warnWrongTransition(event);
        if (!this.checkGuard(event)) {
            return this.warnGuard(event);
        }
        this.applyTransition(rule, event, appliedData);
    };
    StateManagerFSM.prototype.isInitialized = function () {
        return this.stateData.state !== '';
    };
    StateManagerFSM.prototype.warnWrongTransition = function (event) {
        if (this.options.devMode) {
            console.warn("[FSM Warn] Invalid event '".concat(event, "' for state '").concat(this.stateData.state, "'"));
        }
    };
    StateManagerFSM.prototype.warnGuard = function (event) {
        console.warn("[FSM Warn] Guard blocked '".concat(event, "' in state '").concat(this.stateData.state, "'"));
    };
    StateManagerFSM.prototype.applyTransition = function (rule, event, appliedData) {
        var next = rule.transitionAction(this.stateData, { appliedData: appliedData });
        if (this.options.logTransitions) {
            console.log("[FSM] Transition: '".concat(this.stateData.state, "' state \u2192 '").concat(next.state, "' state triggered by '").concat(event, "' event"));
        }
        this.stateData = next;
        if (this.options.subscriptionMode) {
            this.subscriptionManager.notify(next.state, next);
        }
    };
    StateManagerFSM.prototype.transitionAction = function (event) {
        var stateData = this.stateData;
        if (!stateData) {
            return;
        }
        return this.transitionRules[stateData.state][event];
    };
    StateManagerFSM.prototype.checkGuard = function (event) {
        var transition = this.transitionAction(event);
        if (!transition) {
            return true;
        }
        else {
            return transition.transitionGuard
                ? transition.transitionGuard(this.stateData.state, event)
                : true;
        }
    };
    StateManagerFSM.prototype.canTransition = function (event) {
        var transition = this.transitionAction(event);
        if (!transition) {
            if (this.options.devMode) {
                console.warn("[FSM Warn] We can't transition to another state with event '".concat(event, "' from state '").concat(this.stateData.state, "'"));
            }
            return false;
        }
        return typeof transition.transitionAction === 'function';
    };
    StateManagerFSM.prototype.subscribe = function (state, callback) {
        if (!this.options.subscriptionMode) {
            throw new Error('Subscription mode is disabled. ' +
                'Turn on `subscriptionMode: true` in options, for using .subscribe().');
        }
        return this.subscriptionManager.subscribe(state, callback);
    };
    return StateManagerFSM;
}());
exports.StateManagerFSM = StateManagerFSM;