我在一个网站上有一个调查,用户按下回车键(我不知道为什么),不小心没有点击提交按钮就提交了调查(表单),这似乎有些问题。有办法防止这种情况吗?

我在调查中使用HTML, PHP 5.2.9和jQuery。


当前回答

第4.10.22.2节隐式提交的W3C HTML5规范说:

A form element's default button is the first submit button in tree order whose form owner is that form element. If the user agent supports letting the user submit a form implicitly (for example, on some platforms hitting the "enter" key while a text field is focused implicitly submits the form), then doing so for a form whose default button has a defined activation behavior must cause the user agent to run synthetic click activation steps on that default button. Note: Consequently, if the default button is disabled, the form is not submitted when such an implicit submission mechanism is used. (A button has no activation behavior when disabled.)

因此,一种符合标准的禁用表单隐式提交的方法是将禁用的提交按钮作为表单中的第一个提交按钮:

<form action="...">
  <!-- Prevent implicit submission of the form -->
  <button type="submit" disabled style="display: none" aria-hidden="true"></button>

  <!-- ... -->

  <button type="submit">Submit</button>
</form>

这种方法的一个很好的特性是它不需要JavaScript;无论是否启用JavaScript,都需要一个符合标准的web浏览器来防止隐式表单提交。

其他回答

为了阻止表单被提交,我必须捕获所有与按下键相关的三个事件:

    var preventSubmit = function(event) {
        if(event.keyCode == 13) {
            console.log("caught ya!");
            event.preventDefault();
            //event.stopPropagation();
            return false;
        }
    }
    $("#search").keypress(preventSubmit);
    $("#search").keydown(preventSubmit);
    $("#search").keyup(preventSubmit);

你可以把上面所有的组合成一个漂亮的紧凑版本:

    $('#search').bind('keypress keydown keyup', function(e){
       if(e.keyCode == 13) { e.preventDefault(); }
    });

在我对其他解决方案感到沮丧之后,这在所有浏览器中都有效。name_space外层函数只是为了避免声明全局变量,这也是我推荐的。

$(function() {window.name_space = new name_space();}); //jquery doc ready
function name_space() {
    this.is_ie = (navigator.userAgent.indexOf("MSIE") !== -1);

    this.stifle = function(event) {
        event.cancelBubble;
        event.returnValue = false;
        if(this.is_ie === false) {
            event.preventDefault();
        }
        return false;
    }

    this.on_enter = function(func) {
        function catch_key(e) {
            var enter = 13;
            if(!e) {
                var e = event;
            }
            keynum = GetKeyNum(e);
            if (keynum === enter) {
                if(func !== undefined && func !== null) {
                    func();
                }
                return name_space.stifle(e);
            }
            return true; // submit
        }

        if (window.Event) {
            window.captureEvents(Event.KEYDOWN);
            window.onkeydown = catch_key;
        }
        else {
            document.onkeydown = catch_key;
        }

        if(name_space.is_ie === false) {
            document.onkeypress = catch_key;    
        }
    }
}

示例使用:

$(function() {
    name_space.on_enter(
        function () {alert('hola!');}
    );
});

第4.10.22.2节隐式提交的W3C HTML5规范说:

A form element's default button is the first submit button in tree order whose form owner is that form element. If the user agent supports letting the user submit a form implicitly (for example, on some platforms hitting the "enter" key while a text field is focused implicitly submits the form), then doing so for a form whose default button has a defined activation behavior must cause the user agent to run synthetic click activation steps on that default button. Note: Consequently, if the default button is disabled, the form is not submitted when such an implicit submission mechanism is used. (A button has no activation behavior when disabled.)

因此,一种符合标准的禁用表单隐式提交的方法是将禁用的提交按钮作为表单中的第一个提交按钮:

<form action="...">
  <!-- Prevent implicit submission of the form -->
  <button type="submit" disabled style="display: none" aria-hidden="true"></button>

  <!-- ... -->

  <button type="submit">Submit</button>
</form>

这种方法的一个很好的特性是它不需要JavaScript;无论是否启用JavaScript,都需要一个符合标准的web浏览器来防止隐式表单提交。

不需要阻止用户按Enter键(这似乎不自然),您可以让表单保持原样,并添加一些额外的客户端验证:当调查未完成时,结果不会发送到服务器,用户会收到一条漂亮的消息,告诉需要完成哪些内容才能完成表单。如果您正在使用jQuery,请尝试验证插件:

http://docs.jquery.com/Plugins/Validation

这将需要比捕捉Enter按钮更多的工作,但肯定会提供更丰富的用户体验。

在我的情况下,我有一对jQuery UI自动完成字段和文本区域的形式,所以我肯定希望他们接受进入。所以我从表单中删除了type="submit"输入,并添加了一个锚<a href="" id="btn">Ok</a>。然后我把它设置为一个按钮,并添加以下代码:

$( '#btn' ).click( function( event ){
    event.preventDefault();
    if ( validateData() ){
        $( 'form#frm' ).append( '<input type="submit" id="frm-submit" style="display:none;"></input>' );
        setTimeout( function(){ $( '#frm-submit' ).click(); }, 500 );
    }
    return false;
});

如果用户填写了所有必需的字段,validateData()将成功并提交表单。