jquery - 如何在达到限制后停止 sessionStorage 保存值

Question

我一直在试图弄清楚如何在max_fields单击Add Another Worker按钮后停止 sessionStorage 保存值？似乎在达到限制并再次单击按钮后，值不断添加到 sessionStorage 我想知道如何阻止这种情况发生。

这是我的 jsfiddle https://jsfiddle.net/p2euLqbf/4/的链接

HTML

<ul>
    <li>
        <div class="worker-container-last">
            <label class="worker-label">
                <select name="title[]" class="title">
                    <option value="Select a Title" selected="selected">Select a Title</option>
                    <option value="Boss">Boss</option>
                    <option value="Worker">Worker</option>
                    <option value="Manager">Manager</option>
                </select>
            </label>
        </div>
        <div class="add-more"></div>
        <div><a class="worker" title="" href="">Add Another Worker</a></div>
    </li>
</ul>

jQuery

var worker_record = [];
$(document).ready(function(){
    workerData();
    $('.worker').on('click', function(e){
        e.preventDefault();
        e.stopPropagation();

        var title = $('.title:first').val();            

        var someData = {title: title};
        worker_record.push(someData);

        sessionStorage.worker = JSON.stringify(worker_record);
        workerData();
    });

    function workerData(){
        var max_fields = 6;
        var x = 1;

        if(!(typeof sessionStorage.worker === 'undefined' || sessionStorage.worker.length<1)){
            worker_record = JSON.parse(sessionStorage.worker);
        }

        $('.add-more').empty();
        for(var i=0; i<worker_record.length; i++){
            if(x < max_fields){
                x++;
                var title = worker_record[i].title;

                var worker = '<select name="title[]" class="title title-options"><option value="Select a Title" selected="selected">Select a Title</option><option value="Boss">Boss</option><option value="Worker">Worker</option><option value="Manager">Manager</option></select>';

                $('.add-more').append(worker);
                $('.title:eq('+$('.title-options').length+')').val(title);
            }
        }

        $('.title:first').val('Select a Title');
    }
}); 

Answer 1

要设置限制，您可以这样做。

先设置一个变量

if (sessionStorage.getItem("limit") === null) {
    sessionStorage.setItem('limit', 0);
}

在每次迭代时增加这个变量值并相应地设置一个限制检查假设你想设置一个limit = 10然后，

if(sessionStorage.getItem('limit') <= 10 )
{
 var count = sessionStorage.getItem('limit');
     count++;

 sessionStorage.setItem('limit', count);

  //do whatever

}
else{

   alert("session limit reached!");
   return false;

 }

工作演示