jQuery之$.support.xxx

下面这段代码来自jQuery-file-upload 9.19官方Demo

$(function () {
    'use strict';
    // Change this to the location of your server-side upload handler:
    var url = window.location.hostname === 'blueimp.github.io' ?
                '//jquery-file-upload.appspot.com/' : 'server/php/';
    $('#fileupload').fileupload({
        url: url,
        dataType: 'json',
        done: function (e, data) {
            $.each(data.result.files, function (index, file) {
                $('<p/>').text(file.name).appendTo('#files');
            });
        },
        progressall: function (e, data) {
            var progress = parseInt(data.loaded / data.total * 100, 10);
            $('#progress .progress-bar').css(
                'width',
                progress + '%'
            );
        }
    }).prop('disabled', !$.support.fileInput)
        .parent().addClass($.support.fileInput ? undefined : 'disabled');
});

对应的HTML

<input id="fileupload" type="file" name="files[]" multiple>

jQuery.support 用于检查浏览器对各项特性的支持。检查项多达 27 个。经搜索,应该是时从jQuery 1.9 开始.

w3school参考

注意这里的字面值"fileInput",fileupload插件可以使用input标签的id值作为属性名指引所生成的jquery插件对象, 此编程模式待学习研究.