Question

使用下面的jquery占位符插件创建标签并使用标签覆盖该字段。

我的问题是我有一个字段验证和一个将焦点放在返回验证错误的字段上的函数。

通过以编程方式设置焦点，标签/占位符仍然存在。如果我点击该字段，它可以正常工作。

有任何明显的解决方法吗？

/*****************************************************************************
jQuery Placeholder 1.1.1

Copyright (c) 2010 Michael J. Ryan (http://tracker1.info/)

Dual licensed under the MIT and GPL licenses:
    http://www.opensource.org/licenses/mit-license.php
    http://www.gnu.org/licenses/gpl.html

------------------------------------------------------------------------------

Sets up a watermark for inputted fields... this will create a LABEL.watermark
tag immediately following the input tag, the positioning will be set absolute,
and it will be positioned to match the input tag.

To activate on all tags with a 'data-watermark' attribute:

    $('input[placeholder],textarea[placeholder]').placeholder();


To style the tags as appropriate (you'll want to make sure the font matches):

    label.placeholder {
        cursor: text;               <--- display a cursor to match the text input

        padding: 4px 4px 4px 4px;   <--- this should match the border+padding
                                            for the input field(s)
        color: #999999;             <--- this will display as faded
    }

You'll also want to have the color set for browsers with native support
    input:placeholder, textarea:placeholder {
        color: #999999;
    }
    input::-webkit-input-placeholder, textarea::-webkit-input-placeholder {
        color: #999999;
    }

------------------------------------------------------------------------------

Thanks to...
    http://www.alistapart.com/articles/makingcompactformsmoreaccessible
    http://plugins.jquery.com/project/overlabel

    This works similar to the overlabel, but creates the actual label tag
    based on a data-watermark attribute on the input tag, instead of
    relying on the markup to provide it.

*****************************************************************************/
(function($){

    var ph = "PLACEHOLDER-INPUT";
    var phl = "PLACEHOLDER-LABEL";
    var boundEvents = false;
    var default_options = {
        labelClass: 'placeholder'
    };

    //check for native support for placeholder attribute, if so stub methods and return
    var input = document.createElement("input");
    if ('placeholder' in input) {
        $.fn.placeholder = $.fn.unplaceholder = function(){}; //empty function
        delete input; //cleanup IE memory
        return;
    };
    delete input;

    $.fn.placeholder = function(options) {
        bindEvents();

        var opts = $.extend(default_options, options)

        this.each(function(){
            var rnd=Math.random().toString(32).replace(/\./,'')
                ,input=$(this)
                ,label=$('<label style="position:absolute;display:none;top:0;left:0;"></label>');

            if (!input.attr('placeholder') || input.data(ph) === ph) return; //already watermarked

            //make sure the input tag has an ID assigned, if not, assign one.
            if (!input.attr('id')) input.attr('id') = 'input_' + rnd;

            label   .attr('id',input.attr('id') + "_placeholder")
                    .data(ph, '#' + input.attr('id'))   //reference to the input tag
                    .attr('for',input.attr('id'))
                    .addClass(opts.labelClass)
                    .addClass(opts.labelClass + '-for-' + this.tagName.toLowerCase()) //ex: watermark-for-textarea
                    .addClass(phl)
                    .text(input.attr('placeholder'));

            input
                .data(phl, '#' + label.attr('id'))  //set a reference to the label
                .data(ph,ph)        //set that the field is watermarked
                .addClass(ph)       //add the watermark class
                .after(label);      //add the label field to the page

            //setup overlay
            itemIn.call(this);
            itemOut.call(this);
        });
    };

    $.fn.unplaceholder = function(){
        this.each(function(){
            var input=$(this),
                label=$(input.data(phl));

            if (input.data(ph) !== ph) return;

            label.remove();
            input.removeData(ph).removeData(phl).removeClass(ph);
        });
    };


    function bindEvents() {
        if (boundEvents) return;

        //prepare live bindings if not already done.
        $('.' + ph)
            .live('click',itemIn)
            .live('focusin',itemIn)
            .live('focusout',itemOut);
        bound = true;

        boundEvents = true;
    };

    function itemIn() {
        var input = $(this)
            ,label = $(input.data(phl));

        label.css('display', 'none');
    };

    function itemOut() {
        var that = this;

        //use timeout to let other validators/formatters directly bound to blur/focusout work first
        setTimeout(function(){
            var input = $(that);
            $(input.data(phl))
                .css('top', input.position().top + 'px')
                .css('left', input.position().left + 'px')
                .css('display', !!input.val() ? 'none' : 'block');
        }, 200);
    };

}(jQuery));

这是在字段上生成的代码：

<input name="Number" title="Enter Gift Card 1 Number" class="CO_PM_GiftCardNumField PLACEHOLDER-INPUT" id="frmGCD_1_Number" style="width: 144px;" onkeypress="return checkEnter(event,'frmGCD_1')" type="text" maxLength="19" placeholder="Enter gift card" />
<label class="placeholder placeholder-for-input PLACEHOLDER-LABEL" id="frmGCD_1_Number_placeholder" style="position: absolute; display: block; top: 18px; left: 14px;" for="frmGCD_1_Number" >

Answer 1

调用聚焦字段的脚本时尝试trigger()：

$(element).trigger('focus');

如果focus不起作用，请尝试其他活动，例如click或focusin。

Answer 2

好的 - 我修好了。

由于我用另一个脚本设置焦点，我需要在插件中添加焦点（不是焦点）：

.live('click',itemIn)
.live('focusin',itemIn)
.live('focus',itemIn)
.live('focusout',itemOut);
bound = true;

占位符jquery - 程序化焦点

2 个答案: