smart_truncate.js

var truncate = function(string, n, terminator) {
  if (typeof string !== 'string') {
    return;
  }

  var lastIndex = string.lastIndexOf(' ', n), ret = string.toString();

  if(ret.length <= n) return ret;

  if (lastIndex != -1) {
    ret = string.substring(0, lastIndex) + (terminator || '...');
  }

  return ret;
};