/css/jquery-file-upload/jquery.fileupload.css
/css/jquery-file-upload/jquery.fileupload-ui.css
/js/jquery-file-upload/vendor/jquery.ui.widget.js
/js/jquery-file-upload/jquery.iframe-transport.js
/js/jquery-file-upload/jquery.fileupload.js
/js/jquery-file-upload/jquery.fileupload-process.js

<input type="file" name="files" id="file_software" class="file-upload" data-url="http://example.com/file/upload" data-form-data='{"extra": "software"}'>
<ul class="file-list list-unstyled mb-0"></ul>

<?php
$maxUploadFileSize = getUploadMaxFileSize();
$script = <<<SCRIPT
<script>
jQuery(function() {
    jQuery(".file-upload").fileupload({
        dataType: "json",
        maxChunkSize: $maxUploadFileSize,
        sequentialUploads: false,
        add: function(e, data) {
            var maxFileCount = parseInt($(this).data("maxfilecount"));
            if (isNaN(maxFileCount))
                maxFileCount = 1;
            console.log(maxFileCount);
            var \$t = $(this);
            var \$w = \$t.closest("div");
            var \$li = \$w.find("ul.file-list li");
            if (\$li.length >= maxFileCount) {
                var txt = \$w.find("label").text();
                alert("업로드된 " + txt + " 파일이 있습니다. 기존 파일을 삭제하신 후 새로 업로드해 주십시오.");
                return false;
            }
            data.context = $('<li class="file my-1 row"></li>')
                .append(jQuery('<div class="file-name col-md-8 text-muted"></div>').text(data.files[0].name))
                .append('<div class="progress col-md-3 my-auto px-0"><div class="progress-bar progress-bar-striped bg-info" role="progressbar"></div></div>')
                .append('<div class="del-button col-md-1"></div>')
                .appendTo($(this).siblings(".file-list"));
            data.submit();
        },
        progress: function(e, data) {
            var progress = parseInt((data.loaded / data.total) * 100, 10);
            data.context.find(".progress-bar").css("width", progress + "%");
        },
        done: function(e, data) {
            var res = data.result.files[0];
            var val = res.path;
            var url = res.deleteUrl;
            if (res.error !== "") {
                data.context.remove();
                alert(res.error);
                return false;
            }
            jQuery(this.form)
                .find("input[type=hidden]:last")
                .after('<input type="hidden" name="upload[]" value="' + val + '">');
            data.context
                .find(".file-name")
                .removeClass("text-muted")
                .append(' <span class="badge badge-success"><i class="fas fa-check"></i></span>')
                .end()
                .find(".del-button")
                .append('<button type="button" class="btn btn-sm btn-danger upload-delete" data-val="' + val + '" data-type="DELETE" data-url="' + url + '"><i class="far fa-trash-alt"></i></button>');
            jQuery(this).blur();
        }
    });
    jQuery(document).on("click", ".upload-delete", function(e) {
        var \$t   = jQuery(this);
        var val  = \$t.data("val");
        var url  = \$t.data("url");
        var type = \$t.data("type");
        jQuery.ajax({
            url: url,
            type: type,
            success: function(data) {
                \$t.closest("li").remove();
                jQuery("input[name='upload[]']").each(function(i) {
                    var \$el = jQuery(this);
                    if (\$el.val() == val)
                        \$el.remove();
                });
            },
            error: function(request, status, error) {
                console.log("code:"+request.status+"\\n"+"message:"+request.responseText+"\\n"+"error:"+error);
            },
            dataType: "JSON"
        });
    });
    jQuery(document).on("click", ".file-delete", function(e) {
        if(!confirm("파일을 삭제하시겠습니까?"))
            return false;
        var \$t  = jQuery(this);
        var act = \$t.data("act");
        var key = \$t.data("key");
        var no  = \$t.data("no");
        var token = setTokenValue("", "admin");
        jQuery.ajax({
            url: "./filedelete.php",
            data: {act: act, key: key, no: no, token: token},
            success: function(data) {
                if (data.error != "") {
                    alert(data.error);
                    return false;
                }
                \$t.closest("li").remove();
            },
            error: function(request, status, error) {
                console.log("code:"+request.status+"\\n"+"message:"+request.responseText+"\\n"+"error:"+error);
            },
            dataType: "JSON"
        });
    });
});
</script>
SCRIPT;
echo $script;
?>