Get the character user input in input[type="text"] bypassing IME

getCaretText.js

function getCaretPos(input_node) {
  return 'selectionStart' in input_node? input_node.selectionStart: Math.abs(document.selection.createRange().moveStart('character', -input_node.value.length))
}
function getCaretText(input_node) {
  var pos = getCaretPos(input_node)
  if(!pos) return
  return input_node.value.substring(pos - 1, pos)
}
$input_node.on('keyup', function() {
  dosomething(getCaretText($input_node[0]))
})