自定义实时验证功能

时间:2009-12-23 18:15:04

标签: javascript validation xmlhttprequest

我一直在尝试创建自己的自定义LiveValidation(LiveValidation.com)函数,该函数连接到数据库并检查用户名是否已存在。这是表格的相关部分:

    Username: <input type="text" name="username" id="username" class="textinput"> 
    <script type="text/javascript"> 
        var username = new LiveValidation('username');
        username.add( Validate.Presence );
        username.add( Validate.Length, { minimum: 3, maximum: 12 } );
        username.add( Validate.Username );  
    </script>

这是我的Validate.Username函数:

Validate.Username = function(value, paramsObj){

        var paramsObj = paramsObj || {};
        var message = paramsObj.failureMessage || "Sorry that username is taken!";

    var http = new XMLHttpRequest();
    var url = "usernamecheck.php";
    var params = "username="+value;
    http.open("POST", url, true);
    http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    http.setRequestHeader("Content-length", params.length);
    http.setRequestHeader("Connection", "close");
    http.onreadystatechange = function() {
        if(http.readyState == 4 && http.status == 200) {
            if(http.responseText == 'yes') {
                return true;
            } else {
                Validate.fail(message);
                return false;
            }
        }
    }
    http.send(params);
}

这是usernamecheck.php的相关部分:

if(mysql_num_rows($query) != 0 && $query) {
            echo "no";
        } else if ($query) {
            echo "yes";
        } else {
            echo "err";
        }

该函数似乎工作正常(如果我将alert('fail')置于Validate.fail(message);以上,则在使用用户名时会收到警报,但LiveValidation从不显示错误消息。谁知道我做错了什么?

由于

1 个答案:

答案 0 :(得分:1)

嗯...只是快速地看着它,可能是你的功能中没有定义“消息”吗?它在父函数中定义。