51 lines
1 KiB
JavaScript
51 lines
1 KiB
JavaScript
class Store {
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constructor(reducer, catcher) {
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this.reducer = reducer;
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this.catcher = catcher;
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this.subscribers = [];
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try {
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this.state = this.reducer(undefined, {});
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} catch (e) {
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catcher(e);
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}
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}
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dispatch(action, sender) {
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if (action instanceof Promise) {
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action.then((a) => {
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this.transitNext(a, sender);
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}).catch((e) => {
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this.catcher(e, sender);
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});
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} else {
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try {
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this.transitNext(action, sender);
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} catch (e) {
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this.catcher(e, sender);
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}
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}
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return action
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}
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getState() {
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return this.state;
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}
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subscribe(callback) {
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this.subscribers.push(callback);
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}
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transitNext(action, sender) {
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let newState = this.reducer(this.state, action);
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if (JSON.stringify(this.state) !== JSON.stringify(newState)) {
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this.state = newState;
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this.subscribers.forEach(f => f(sender));
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}
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}
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}
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const empty = () => {};
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export function createStore(reducer, catcher = empty) {
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return new Store(reducer, catcher);
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}
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