A document.log() implementation

DocumentLog.js

/**
 * Add a 'pre' tag, with a specified id, to the page and log the arguments passed to it
 *
 * WIP:
 * - support array & object deep log
 * - option to log in console (last parameter)
 */
function documentLog (...arg) {
  if (!arg || !arg.length) return
  if (!((typeof arg[0]) === 'string')) return
  let res, i, len
  if (!(res = document.getElementById(arg[0]))) {
    (res = document.createElement('pre')).setAttribute('id', arg[0])
    document.body.appendChild(res)
  }
  for (i = 1, len = arg.length - 1; i < len; i++) res.innerHTML += arg[i] + ' '
  res.innerHTML += arg[i]
}

/**
 * Usage :
 *  First parameter is the id of the 'pre' tag to be used for logging
 *  You can log any js expression
 */
documentLog('someid', 'hello', window, typeof document, [1, 2, 3])

/**
 * You can use it multiple times,
 * if it find the specified id it will log the arguments to it
 * else it will create a new 'pre' tag
 *
 * [JS Standard](https://standardjs.com/demo.html?gist=da1fce7645fc1b6653df40f05ab0b3e1)
 */