64 lines
3.8 KiB
JavaScript
64 lines
3.8 KiB
JavaScript
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function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); enumerableOnly && (symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; })), keys.push.apply(keys, symbols); } return keys; }
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function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = null != arguments[i] ? arguments[i] : {}; i % 2 ? ownKeys(Object(source), !0).forEach(function (key) { _defineProperty(target, key, source[key]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)) : ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } return target; }
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function _defineProperty(obj, key, value) { key = _toPropertyKey(key); if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
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function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return typeof key === "symbol" ? key : String(key); }
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function _toPrimitive(input, hint) { if (typeof input !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (typeof res !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
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/**
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* @typedef {Object} StateDefinitions
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* @property {{[event: string]: { target: string; actions?: Array<string> }}} [on]
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*/
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/**
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* @typedef {Object} Options
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* @property {{[state: string]: StateDefinitions}} states
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* @property {object} context;
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* @property {string} initial
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*/
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/**
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* @typedef {Object} Implementation
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* @property {{[actionName: string]: (ctx: object, event: any) => object}} actions
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*/
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/**
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* A simplified `createMachine` from `@xstate/fsm` with the following differences:
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*
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* - the returned machine is technically a "service". No `interpret(machine).start()` is needed.
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* - the state definition only support `on` and target must be declared with { target: 'nextState', actions: [] } explicitly.
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* - event passed to `send` must be an object with `type` property.
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* - actions implementation will be [assign action](https://xstate.js.org/docs/guides/context.html#assign-action) if you return any value.
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* Do not return anything if you just want to invoke side effect.
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*
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* The goal of this custom function is to avoid installing the entire `'xstate/fsm'` package, while enabling modeling using
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* state machine. You can copy the first parameter into the editor at https://stately.ai/viz to visualize the state machine.
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*
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* @param {Options} options
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* @param {Implementation} implementation
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*/
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function createMachine(_ref, _ref2) {
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var states = _ref.states,
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context = _ref.context,
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initial = _ref.initial;
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var actions = _ref2.actions;
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var currentState = initial;
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var currentContext = context;
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return {
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send: function send(event) {
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var currentStateOn = states[currentState].on;
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var transitionConfig = currentStateOn && currentStateOn[event.type];
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if (transitionConfig) {
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currentState = transitionConfig.target;
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if (transitionConfig.actions) {
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transitionConfig.actions.forEach(function (actName) {
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var actionImpl = actions[actName];
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var nextContextValue = actionImpl && actionImpl(currentContext, event);
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if (nextContextValue) {
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currentContext = _objectSpread(_objectSpread({}, currentContext), nextContextValue);
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}
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});
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}
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}
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}
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};
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}
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export default createMachine;
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