38 lines
856 B
JavaScript
38 lines
856 B
JavaScript
/** ELGEvents
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* Publish/Subscribe pattern to quickly signal events to
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* the plugin, property inspector and data.
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*/
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const ELGEvents = {
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eventEmitter: function (name, fn) {
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const eventList = new Map();
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const on = (name, fn) => {
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if (!eventList.has(name)) eventList.set(name, ELGEvents.pubSub());
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return eventList.get(name).sub(fn);
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};
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const has = name => eventList.has(name);
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const emit = (name, data) => eventList.has(name) && eventList.get(name).pub(data);
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return Object.freeze({on, has, emit, eventList});
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},
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pubSub: function pubSub() {
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const subscribers = new Set();
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const sub = fn => {
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subscribers.add(fn);
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return () => {
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subscribers.delete(fn);
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};
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};
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const pub = data => subscribers.forEach(fn => fn(data));
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return Object.freeze({pub, sub});
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}
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};
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const EventEmitter = ELGEvents.eventEmitter(); |