john-doherty

/**
 * Adds query params to existing URLs (inc merging duplicates)
 * @param {string} url - src URL to modify
 * @param {object} params - key/value object of params to add
 * @example
 * // returns /guides?tag=api
 * addQueryParamsToUrl('/guides?tag=hardware', { tag:'api' })
 * @example
 * // returns https://orcascan.com/guides?tag=api
 * addQueryParamsToUrl('https://orcascan.com/guides?tag=hardware', { tag: 'api' })

john-doherty

# Disable DPMS.
xset s off         # don't activate screensaver
xset -dpms         # disable DPMS (Energy Star) features.
xset s noblank     # don't blank the video device

# Create a RAM disk to use as a FIFO for streaming.
if [ ! -d /iwk ]; then
    mkdir /tmp/rdisk
fi
mount -t tmpfs -o size=25M tmsfs /tmp/rdisk

john-doherty

/**
 * Convert a URL into a readable filename safe string
 * - sort query params
 * - remove protocol
 * - replace / with !
 * - replace ? with !!
 * - replace remaining illegal characters with -
 * @example
 *  INPUT: convertUrlToReadableFilename('https://orcascan.com/guides/how-to-scan-barcodes-into-microsoft-excel-59fd67f9');

john-doherty

/**
 * Executes an array of functions that return a promise in sequence
 * @example
 * promisesInSequence([
 *      function() { return Promise.resolve(1); }
 *      function() { return Promise.resolve(2); },
 *      function() { return Promise.resolve(3); }
 *  ])
 *  .then(function(result) {
 *      console.log(result.join(',')); // output = 1,2,3

john-doherty

/**
 * Wait for the browser to fire an event (including custom events)
 * @param {string} eventName - Event name
 * @param {integer} seconds - number of seconds to wait.
 * @returns {Promise} resolves when event fires or timeout is reached
 */
async function waitForEvent(eventName, seconds) {

    seconds = seconds || 30;

john-doherty

/**
 * Waits for multiple DOM events to fire
 * @example
 * waitForEvents(window, [
 *      'DOMContentLoaded',
 *      'online'
 *  ])
 *  .then(function(result) {
 *      // do stuff

john-doherty

var fileStorage = {

    /**
     * Saves a file on the device
     * @param {string} name - filename (can include sub folders)
     * @param {string} data - file contents
     * @param {boolean} useSandbox - uses protected sandbox if true, otherwise external (default false)
     * @returns {Promise} executes .then with saved file path as first param
     */
    write: function (name, data, useSandbox) {

john-doherty

/**
 * local storage helper (takes care of casting types)
 */
var localStorageHelper = {

    /**
     * Check if item exists in local storage.
     * @param {string} key - variable name
     * @return {boolean} true if key exists, otherwise false
     */

john-doherty

function trimSvgWhitespace() {

  // get all SVG objects in the DOM
  var svgs = document.getElementsByTagName("svg");

  // go through each one and add a viewbox that ensures all children are visible
  for (var i=0, l=svgs.length; i<l; i++) {

    var svg = svgs[i],
        box = svg.getBBox(), // <- get the visual boundary required to view all children

john-doherty

(function (window) {

    if ((/Macintosh/gi).test(navigator.userAgent) && (/Chrome|Safari|Firefox/gi).test(navigator.userAgent)) {

        history.pushState(null, null, location.href);
        window.onpopstate = function(event) {
            history.go(1);
        };
    }