33 lines
675 B
JavaScript
33 lines
675 B
JavaScript
export default class BaseObservableCollection {
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constructor() {
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this._handlers = new Set();
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}
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onSubscribeFirst() {
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}
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onUnsubscribeLast() {
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}
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subscribe(handler) {
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this._handlers.add(handler);
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if (this._handlers.size === 1) {
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this.onSubscribeFirst();
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}
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return () => {
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if (handler) {
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this._handlers.delete(this._handler);
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if (this._handlers.size === 0) {
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this.onUnsubscribeLast();
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}
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handler = null;
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}
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return null;
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};
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}
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// Add iterator over handlers here
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}
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