javascript - jQuery隐藏ajax优化

Question

jQuery('select[field]').each(function(){
    var jobj = $(this);
    var pre_field_name = jobj.attr('filtered_by');
    var parent_field_name = jobj.attr('field');
    var data_url =jobj.attr('data-url');
    var val = jobj.val();
    $('select[name='+parent_field_name+']').change(function(){
        console.log('change');
        if($(this).val()){
            console.log('ajax');
            $.get(data_url, {'pk': $(this).val()}, function(response){
                console.log('response');
                var options = '';
                for (var i = 0; i < response.length; i++) {
                    options += '<option value="' + response[i].value + '" '+  (val==response[i].value?'selected="selected"':'') +  '>' + response[i].display + '</option>';
                }
                jobj.html(options);
                jobj.change();
            })
        } else {
            jobj.html('<option value="">------</option>');
            jobj.change();
        }
    }).change();

})

如果我的页面上有 3 个元素满足此 jQuery('select[field]') 选择器 - 那么，在 chrome 日志中我会看到 6 个(由 .change 翻倍) ()我猜)响应日志记录。但在 chrome 控制台的 network 选项卡和服务器日志中，我看到只有一个请求。可能是什么原因？

Answer 1

这不是隐藏优化，而是documented缓存 http 响应的行为，

缓存

If set to false, it will force requested pages not to be cached by the browser. Note: Setting cache to false will only work correctly with HEAD and GET requests. It works by appending "_={timestamp}" to the GET parameters. The parameter is not needed for other types of requests, except in IE8 when a POST is made to a URL that has already been requested by a GET.