在IE

Question

请检查以下代码。这在Firefox和Chrome上工作正常，但在Internet Explorer 11上出现以下错误。因此，所需的wordpress图像弹出功能无法在IE上运行。

SCRIPT5007：无法获取未定义或空引用的属性

$(document).on('click', '.dfiFeaturedImage', function() {

        current = $(this);

        if( null !== current) {

            var dfi_uploader = wp.media({

                title: WP_SPECIFIC.mediaSelector_title,
                button: {
                    text: WP_SPECIFIC.mediaSelector_buttonText
                },
                multiple: false,

            }).on('select', function() {

                var attachment = dfi_uploader.state().get('selection').first().toJSON(),
                    fullSize = attachment.url,
                    imgUrl = (typeof attachment.sizes.thumbnail === "undefined") ? fullSize : attachment.sizes.thumbnail.url,
                    imgUrlTrimmed, fullUrlTrimmed;

                imgUrlTrimmed = imgUrl.replace(WP_SPECIFIC.upload_url, "");
                fullUrlTrimmed = fullSize.replace(WP_SPECIFIC.upload_url, "");

                var featuredBox = current.parent();

                featuredBox.find('.fImg').attr({
                    'src': imgUrl,
                    'data-src': fullSize
                });

                featuredBox.find('.dfiFeaturedImage').addClass('hasFeaturedImage');

                var dfiFeaturedImages = [imgUrlTrimmed, fullUrlTrimmed];

                /**
                 * Check if medium sized image exists
                 * @type object
                 */
                var medium = attachment.url;
                if( typeof attachment.sizes.medium !== "undefined" ) {
                    medium = attachment.sizes.medium.url;
                }

                featuredBox.find('img').attr('src', medium).fadeIn(200);
                featuredBox.find('input.dfiImageHolder').val(dfiFeaturedImages);

            }).open();  
        }

        return false;

    });