EPiServer CMS 7.5 gadget to export a zip-file containing all files for a specific page

ExportPageFilesController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Mvc;
using EPiServer;
using EPiServer.Core;
using EPiServer.Shell.Gadgets;
using Ionic.Zip;

namespace Website.Web.Gadgets.Controllers
{
    [Gadget(Name = "Export page files", Title = "Export page files")]
    [Authorize(Roles = "WebAdmins")]
    public class ExportPageFilesController : Controller
    {
        private readonly IContentLoader _contentLoader;
        private readonly ContentAssetHelper _contentAssetHelper;

        public ExportPageFilesController(IContentLoader contentLoader, ContentAssetHelper contentAssetHelper)
        {
            _contentLoader = contentLoader;
            _contentAssetHelper = contentAssetHelper;
        }

        public ActionResult Index(string url)
        {
            var model = new ExportFileModel()
            {
                Url = url
            };

            if (string.IsNullOrEmpty(url)) return View(model);

            object page;
            var pr = Global.UrlRewriteProvider.ConvertToInternal(new UrlBuilder(url), out page);

            if (pr)
            {
                var pageReference = page as PageReference;

                if (pageReference != null)
                {
                    var folder = _contentAssetHelper.GetAssetFolder(pageReference);

                    if (folder != null)
                    {
                        model.PageReference = pageReference;
                        model.Files = GetFiles(folder).ToList();
                        model.TotalFileSize = model.Files.Sum(e => e.FileSize);
                    }
                }
            }
            return View(model);
        }

        public void DownloadFiles(string reference)
        {
            var pageReference = PageReference.Parse(reference);
            if (pageReference == null) return;

            var folder = _contentAssetHelper.GetAssetFolder(pageReference);
            if (folder == null) return;

            var files = GetFiles(folder);
            CreateZipFile(files);
        }

        public void CreateZipFile(IEnumerable<ExportFileItemModel> files)
        {
            using (var zip = new ZipFile())
            {
                var zipName = String.Format("pagefileexport_{0}.zip", DateTime.Now.ToString("yyyy-MMM-dd-HHmmss"));

                zip.AlternateEncodingUsage = ZipOption.AsNecessary;

                foreach (var file in files)
                {
                    zip.AddFile(file.Path, "Files").FileName = file.FileName;
                }

                Response.Clear();
                Response.BufferOutput = false;
                Response.ContentType = "application/zip";
                Response.AddHeader("content-disposition", "attachment; filename=" + zipName);
                zip.Save(Response.OutputStream);
                Response.End();
            }
        }

        private IEnumerable<ExportFileItemModel> GetFiles(ContentAssetFolder folder)
        {
            var appDataBasePath = EPiServer.Framework.Configuration.EPiServerFrameworkSection.Instance.AppData.BasePath;
            foreach (var item in _contentLoader.GetChildren<MediaData>(folder.ContentLink))
            {
                var virtualPath = item.BinaryData.ID.AbsolutePath;
                yield return new ExportFileItemModel
                {
                    FileName = item.Name,
                    Path = string.Format(@"{0}\blobs\{1}", appDataBasePath, virtualPath),
                    FileSize = (item.BinaryData != null) ? (item.BinaryData.OpenRead().Length/1024.0)/1024.0 : 0,
                    ContentLink = item.ContentLink
                };
            }
        }
    }

    public class ExportFileModel
    {
        public string Url { get; set; }
        public List<ExportFileItemModel> Files { get; set; }
        public PageReference PageReference { get; set; }
        public double TotalFileSize { get; set; }
    }

    public class ExportFileItemModel
    {
        public string FileName { get; set; }
        public string Path { get; set; }
        public ContentReference ContentLink { get; set; }
        public double FileSize { get; set; }

    }
}

Index.cshtml

@using EPiServer.Shell.Web.Mvc.Html
@model  Website.Web.Gadgets.Controllers.ExportFileModel
@{
    Layout = null;
}

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Export page files</title>

    <style type="text/css">
        .gadget-body {
            padding: 20px;
        }
    </style>
</head>

<body>
    <div class="gadget-body">
        @using (Html.BeginGadgetForm("Index"))
        {
            <h2>Page URL</h2>
            <input name="url" value="@(Model.Url ?? "")" />
            <input type="submit" />
        }

        @if (Model != null)
        {
            if (Model.Files != null)
            {
                <h2>Page files</h2>

                if (Model.PageReference != null)
                {
                    <span class="epi-button">
                        <span class="epi-button-child">
                            <a class="epi-button-child-item" href='@Url.Action("DownloadFiles", "ExportPageFiles", new {reference = Model.PageReference})'>
                                Download all files (@Model.Files.Count file(s), @Math.Round(Model.TotalFileSize, 2) mb)
                            </a>
                        </span>
                    </span>
                    <br /><br />
                }

                <table>
                    @foreach (var file in Model.Files)
                    {
                        <tr>
                            <td><a href="@Url.ContentUrl(file.ContentLink)" target="_blank">@file.FileName</a></td>
                            <td>@Math.Round(file.FileSize, 2) mb</td>
                        </tr>
                    }
                </table>
            }
        }
    </div>
</body>
</html>