andrewluetgers’s gists

andrewluetgers / App.js

Last active March 10, 2021 17:39

Image loading with react-konva

	import React, { Component } from 'react';
	import DevTools from 'mobx-react-devtools';
	import Konva from 'konva';
	import {Stage, Layer, Rect, Line, Image} from 'react-konva';
	import Img from './Img/Img.js';
	import './App.css';
	import pg from '../assets/scribo-doc-dia-00008061.json'

	console.log(pg);

andrewluetgers / DynamoDB to JSON

Last active February 25, 2017 07:09

	function mapper(data, setType) {

	let keys = Object.keys(data),
	ret = data.concat ? [] : {};

	console.log("keys", keys);

	while (keys.length) {
	let key = keys.shift(),
	obj = data[key];

andrewluetgers / LambdaDDBChangeFeedTrigger.js

Last active March 2, 2017 17:30

DynamoDB Simple Change-Feed Lambda Trigger

	/**
	* @license
	* Lodash (Custom Build) lodash.com/license \| Underscore.js 1.8.3 underscorejs.org/LICENSE
	* Build: `lodash include="isObject,isEqual"`
	*/
	;(function(){function t(t,e){for(var r=-1,n=null==t?0:t.length,o=0,a=[];++r<n;){var i=t[r];e(i,r,t)&&(a[o++]=i)}return a}function e(t,e){for(var r=-1,n=null==t?0:t.length;++r<n;)if(e(t[r],r,t))return true;return false}function r(t){return function(e){return t(e)}}function n(t){var e=-1,r=Array(t.size);return t.forEach(function(t,n){r[++e]=[n,t]}),r}function o(t){var e=-1,r=Array(t.size);return t.forEach(function(t){r[++e]=t}),r}function a(){}function i(t){var e=-1,r=null==t?0:t.length;for(this.clear();++e<r;){
	var n=t[e];this.set(n[0],n[1])}}function c(t){var e=-1,r=null==t?0:t.length;for(this.clear();++e<r;){var n=t[e];this.set(n[0],n[1])}}function s(t){var e=-1,r=null==t?0:t.length;for(this.clear();++e<r;){var n=t[e];this.set(n[0],n[1])}}function u(t){var e=-1,r=null==t?0:t.length;for(this.__data__=new s;++e<r;)this.add(t[e])}function f(t){this.size=(th

andrewluetgers / syncStore.js

Created March 2, 2017 17:49

	// work in progress

	// problem: you push a change to the database now your whole app needs to also update to that change
	// one solution is to fetch the data back from the server just after it has changed
	// this assumes acid updates, elastic search is not acid, nor are many nosql databases
	// this is an impossible solution without acid
	// the alternative is to retain an in memory copy of the data and update it optimistically
	// if there is an error from the server roll back the in memory change
	// if there is no error the update is already in memory, barring any server side transformations not accounted for
	// to make this work you need to keep each object in memory over time,

andrewluetgers / activate.js

Created December 14, 2017 16:39

memoized debounce

	// debounce function if arguments do not change
	// https://github.com/lodash/lodash/issues/2403#issuecomment-290760787
	function activate(func, wait=0, options={}) {
	var mem = _.memoize(function() {
	return _.debounce(func, wait, options)
	}, options.resolver);
	return function(){mem.apply(this, arguments).apply(this, arguments)}
	}

andrewluetgers / SpoolMath.html

Created February 12, 2019 17:15

Reel to reel demo

	<html>
	<body>

	<script>

	function round(n) {
	return Math.round(n * 100)/100
	}

	// parameters for 35mm microfilm rolls

andrewluetgers / selectParent.js

Last active February 28, 2019 16:08

Select a parent node that matches a query selector.

	export default function selectParent(el, selector) {
	let parent = null,
	p = el.parentNode,
	pp = p.parentNode,
	sel = pp ? pp.querySelector(selector) : null,
	done = !pp \|\| sel === p;

	console.log(selector, el)
	return done ? sel : selectParent(p, selector);
	}

andrewluetgers / auc.js

Created April 2, 2019 14:51

integration, auc, interpolation fns

	// get n linear steps between point{x, y} a and b
	function interPoints(a, b, n) {
	let int = (t) => ({
	x: a.x * (1 - t) + b.x * t,
	y: a.y * (1 - t) + b.y * t
	}),
	step = 1/(n+1),
	ret = [];

	for (let i=0; i<n; i++) {

andrewluetgers / simpleRulesEngine.js

Created September 14, 2020 20:28

	import {every, filter} from 'lodash'


	export const numericComparisons = {
	lte: (a, b) => a <= b,
	lt: (a, b) => a < b,
	gt: (a, b) => a > b,
	gte: (a, b) => a >= b,
	eq: (a, b) => a === b,
	neq: (a, b) => a !== b

andrewluetgers / useThisState.js

Created October 16, 2020 18:40

Works like useState but for Class Components using this.setState

	function useThisState(key, component, initialState) {
	let set = (val) => component.setState({[key]: val}),
	initial = !(key in component.state)

	if (initial) {
	set(initialState)
	}

	let retVal = initial ? initialState : component.state[key]

Andrew Luetgers andrewluetgers