24 lines
830 B
Plaintext
24 lines
830 B
Plaintext
"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.fromSharedEvent = fromSharedEvent;
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const rxjs_1 = require("rxjs");
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const sharedEvents = new WeakMap();
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/**
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* Creates an observable for a specific event of an `EventEmitter` instance.
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*
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* The underlying event listener is set up only once across the application for that event emitter/name pair.
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*/
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function fromSharedEvent(emitter, event) {
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let emitterEvents = sharedEvents.get(emitter);
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if (!emitterEvents) {
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emitterEvents = new Map();
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sharedEvents.set(emitter, emitterEvents);
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}
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let observable = emitterEvents.get(event);
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if (!observable) {
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observable = (0, rxjs_1.fromEvent)(emitter, event).pipe((0, rxjs_1.share)());
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emitterEvents.set(event, observable);
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}
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return observable;
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}
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