86 lines
2.2 KiB
JavaScript
86 lines
2.2 KiB
JavaScript
import Service, { inject as service } from '@ember/service';
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import { set } from '@ember/object';
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import flat from 'flat';
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import { createMachine, interpret } from '@xstate/fsm';
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export default class StateService extends Service {
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@service('logger')
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logger;
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// @xstate/fsm
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log(chart, state) {
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// this.logger.execute(`${chart.id} > ${state.value}`);
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}
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addGuards(chart, options) {
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this.guards(chart).forEach(function([path, name]) {
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// xstate/fsm has no guard lookup
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set(chart, path, function() {
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return !!options.onGuard(...[name, ...arguments]);
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});
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});
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return [chart, options];
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}
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machine(chart, options = {}) {
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return createMachine(...this.addGuards(chart, options));
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}
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prepareChart(chart) {
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// xstate/fsm has no guard lookup so we clone the chart here
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// for when we replace the string based guards with functions
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// further down
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chart = JSON.parse(JSON.stringify(chart));
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// xstate/fsm doesn't seem to interpret toplevel/global events
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// artificially add them here instead
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if (typeof chart.on !== 'undefined') {
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Object.values(chart.states).forEach(function(state) {
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if (typeof state.on === 'undefined') {
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state.on = chart.on;
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} else {
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Object.keys(chart.on).forEach(function(key) {
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if (typeof state.on[key] === 'undefined') {
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state.on[key] = chart.on[key];
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}
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});
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}
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});
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}
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return chart;
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}
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// abstract
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matches(state, matches) {
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if (typeof state === 'undefined') {
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return false;
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}
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const values = Array.isArray(matches) ? matches : [matches];
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return values.some(item => {
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return state.matches(item);
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});
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}
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state(cb) {
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return {
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matches: cb,
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};
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}
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interpret(chart, options) {
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chart = this.prepareChart(chart);
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const service = interpret(this.machine(chart, options));
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// returns subscription
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service.subscribe(state => {
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if (state.changed) {
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this.log(chart, state);
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options.onTransition(state);
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}
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});
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return service;
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}
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guards(chart) {
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return Object.entries(flat(chart)).filter(([key]) => key.endsWith('.cond'));
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}
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}
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