karenpeng’s gists

karenpeng / websocket_client.js

Last active March 19, 2019 21:34

	const wsConnection = new WebSocket('ws://localhost:3000/websocket');

	wsConnection.onopen = () => {
	console.log('websocket connection is opened')
	wsConnection.send('A');
	};

	wsConnection.onmessage = event => {
	if (event.data === '9') {
	setTimeout(() => {

karenpeng / websocket_server.js

Last active March 20, 2019 18:38

	// example below is using express and express-ws
	app.ws('/websocket', (ws, req) => {
	ws.on('message', (msg) => {
	if (msg === 'A') {
	ws.send('9');
	}
	});
	});

karenpeng / longpolling_server.js

Last active March 20, 2019 18:39

	// example below uses express.js
	let counter = 0;
	app.get('/longpolling', (req, res, next) => {
	const delay = Math.random();
	setTimeout(() => {
	res.send({
	random: delay,
	sequence: counter
	});
	counter++;

karenpeng / longpolling_client.js

Last active March 22, 2019 09:02

	import { fetchUrl } from 'fetch';

	const registerLongPolling = () => {
	let counter = 0;
	fetchUrl('http://localhost:3000/longpolling', (error, meta, body) => {
	if (error) {
	return;
	}

	if (counter > 4) {

karenpeng / sse_server.js

Last active March 19, 2019 08:01

	/* On the server side, when get the request from eventSource,
	* response with content type as 'text/event-stream',
	* and write data in the format according to
	* https://www.w3.org/TR/2009/WD-eventsource-20090421/
	*/
	const constructSSEMsg = (res, id, data) => {
	res.write('id: ' + id + '\n');
	res.write('data: ' + data + '\n\n');
	};

karenpeng / sse_client.js

Last active March 17, 2019 23:57

	const evtSource = new EventSource('/sse');
	evtSource.onmessage = event => {
	try {
	const jsonData = JSON.parse(event.data);
	console.log(jsonData);
	} catch (e) {
	console.log(e);
	}
	}

karenpeng / throttle_debounce.js

Created April 15, 2018 01:07

karenpeng / functionProcesser.js

Created May 5, 2016 23:34

	function functionsProcessor(funcArr, initValue, ...args) {
	if(!funcArr.length) return initValue
	var cur = funcArr.shift()
	return functionsProcessor(funcArr, cur(initValue, ...args), ...args)
	}

	function functionsProcessor(funcArr, initValue, ...args) {
	for(var i = 0; i < funcArr.length; i++){
	initValue = funcArr[i](initValue, ...args)
	}

karenpeng / object_deepEqual.js

Created February 19, 2016 00:24

	var assert = require('assert')

	function deepEqual(obj1, obj2){
	var keys1 = Object.keys(obj1)
	var keys2 = Object.keys(obj2)

	if(keys1.length !== keys2.length) return false

	for(var key in obj1){

karenpeng / onload.md

Created February 19, 2016 00:04

    window.onload          dom tree, img, videos ready
document.onload        dom tree ready
$('document').ready()  dom tree ready

  

Karen Peng karenpeng