43 lines
868 B
JavaScript
43 lines
868 B
JavaScript
/**
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* Implementation of a simple Oberver Pattern for custom event handling
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*/
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function Observer() {
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this.handlers = new Set();
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}
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Observer.prototype = {
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// Adds handler for this message
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on(callback) {
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this.handlers.add(callback);
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return callback;
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},
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clear(callback) {
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return this.handlers.delete(callback);
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},
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emit(msg) {
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this.handlers.forEach(async (handler) => {
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try {
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await handler(msg);
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} catch (e) {
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console.warn("Observer failed to run handler");
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console.warn(handler);
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}
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});
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},
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};
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/**
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* Generates unique id
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*/
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const guid = (size = 3) => {
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const s4 = () => {
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return Math.floor((1 + Math.random()) * 0x10000)
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.toString(16)
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.substring(1);
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};
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// returns id of format 'aaaaaaaa'-'aaaa'-'aaaa'-'aaaa'-'aaaaaaaaaaaa'
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let id = "";
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for (var i = 0; i < size - 1; i++) id += s4() + "-";
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id += s4();
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return id;
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};
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