Vanilla JS + JAM Stack Scrabble Lite Game

https://word-scramble.netlify.app/

Background

The original concept for this app was created for the November 2020 Thanksgiving week Codepen Challenge; the task was to create a Codepen celebrating the game of Scrabble.

To challenge myself and gain a deeper understanding of CSS Custom Properties and JavaScript animation events I decided create this app using 0 dependencies or animation libraries.

Since the "back-end" portion of the application is just a single route/function verifying the word is real I opted to use Netlify serverless functions to make it a JAM stack application.

Technology used

• SCSS
• CSS Custom Properties (Variables)
• Netlify Serverless functions
• Nodejs require.resolve() to read the dictionary file
• ES6/ESNext Map
• webpack 4

Concepts

webpack 4 bundling

Using my own custom webpack 4 dev and production configuration to have a local dev-server with hot module replacement and optimizied production build with minification, auto-prefixing for CSS properties and more.

Double tap custom event with closures

To make it quicker for mobile users to submit their answer I implemented a doubleTap event listener that utilizes closures and a setTimeout to determine if a double tap occured.

/* Based on this http://jsfiddle.net/brettwp/J4djY/*/
function detectDoubleTapClosure() {
  let lastTap = 0;
  let timeout;
  return function detectDoubleTap(event) {
    const curTime = new Date().getTime();
    const tapLen = curTime - lastTap;
    if (tapLen < 500 && tapLen > 0) {
      console.log('Double tapped!');
      event.preventDefault();
    } else {
      timeout = setTimeout(() => {
        clearTimeout(timeout);
      }, 500);
    }
    lastTap = curTime;
  };
}

/* Regex test to determine if user is on mobile */
if (/Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)) {
  docum

Netlify Serverless functions reading local files

To my knowledge I did not see any previous material that implied it was possible to also upload a static file (like my JSON file) and access it via the Netlify Serverless function. Here I did it using Node's require.resolve()

Notice how the folder name must match the file name.

const fs = require("fs");

exports.handler = function(event, context, callback) {
  const dictionary = JSON.parse(
    fs.readFileSync(require.resolve("./data/small_dictionary.json"), "utf-8")
  );
  const { word } = JSON.parse(event.body);
  const res = dictionary.findIndex(e => e === word);
  callback(null, {
    statusCode: 200,
    body: res === -1 ? "false" : "true"
  });
};

Caculating 2D vectors in CSS to get animation path

I used CSS custom properties and JavaScript to change the values of the of the x and y position that the tile would move to based on their absolute position of the window/document.

function computeVector(startCoords, endCoords) {
  let xDist = startCoords[0] - endCoords[0];
  startCoords[0] > endCoords[0] ? (xDist *= -1) : (xDist *= -1);
  let yDist = -(startCoords[1] - endCoords[1]); //Always negative ; moves up to answer board
  document.documentElement.style.setProperty("--tx", `${xDist}px`);
  document.documentElement.style.setProperty("--ty", `${yDist}px`);
}