关于 html:HTML5 Validation with Opera and Safari

    <form class="sign-in-form" action="" method="post">
       
<li>

            <label>
                <span>Username</span>
                <input placeholder="Please enter your username" name="username" type="text" tabindex="1" title="It must contain the username that you have chosen at registration" required autofocus>
            </label>
       
</li>

       
<li>

            <label>
                <span>Password</span>
                <input placeholder="Please enter your password" name="password" type="password" tabindex="2" title="It must contain the password that you have chosen at registration" required>
            </label>
       
</li>

       
<li>

            <button name="sign-in-btn" type="submit" id="sign-in-submit">Sign In</button>
       
</li>

    </form>

(function() {

  var loadScript = function(src, loadCallback) {
    var s = document.createElement(‘script’);
    s.type = ‘text/javascript’;
    s.src = src;
    s.onload = loadCallback;
    document.body.appendChild(s);
  };

  // http://stackoverflow.com/questions/9847580/how-to-detect-safari-chrome-ie-firefox-and-opera-browser
  var isSafari = Object.prototype.toString.call(window.HTMLElement).indexOf(‘Constructor’) > 0;
  var isOpera = !!window.opera || navigator.userAgent.indexOf(‘ OPR/’) >= 0;

  if (isSafari || isOpera) {

    loadScript(‘//code.jquery.com/jquery-2.1.4.min.js’, function () {
      loadScript(‘//cdnjs.cloudflare.com/ajax/libs/webshim/1.15.10/dev/polyfiller.js’, function () {

        webshims.setOptions(‘forms’, {
          overrideMessages: true,
          replaceValidationUI: false
        });
        webshims.setOptions({
          waitReady: true
        });
        webshims.polyfill();
      });
    });
  }

})();

<style type="text/css">
    input.invalid, select.invalid, textarea.invalid {
      border-color: #ff0000;
      background-image: url(‘../img/required.png’);
      background-position: right top;
      background-repeat: no-repeat;
      -moz-box-shadow: none;
    }
    input:required:valid, textarea:required:valid, select:required:valid {
      border: 1px solid #cccccc;
      background-image: none;
    }
    input[type=number]::-webkit-inner-spin-button,
    input[type=number]::-webkit-outer-spin-button {
      -webkit-appearance: none;
      margin: 0;
    }
</style>

<form action="" method="get" accept-charset="utf-8">
    <input type="text" name="name" required>
</form>

<script type="text/javascript">
// Force Validation
function html5Validation () {
  //Check if validation supported && not safari
  return (typeof document.createElement(‘input’).checkValidity === ‘function’) &&
    !(navigator.userAgent.search("Safari") >= 0 && navigator.userAgent.search("Chrome") < 0);
}

$(‘form’).submit(function(){
  if(!html5Validation())
  {
    var isValid = true;
    var $inputs = $(this).find(‘[required]’);
    $inputs.each(function(){
      var $input = $(this);
      $input.removeClass(‘invalid’);
      if(!$.trim($input.val()).length)
      {
        isValid = false;
        $input.addClass(‘invalid’);                
      }
    });
    if(!isValid)
    {
      return false;
    }
  }
});