/* ****************************************************************************
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
* This software is subject to the Microsoft Public License (Ms-PL).
* A copy of the license can be found in the license.htm file included
* in this distribution.
*
* You must not remove this notice, or any other, from this software.
*
* ***************************************************************************/
namespace System.Web.Mvc{
using System;
using System.Web;
public class HttpPostedFileBaseModelBinder : IModelBinder {
public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) {
if (controllerContext == null) {
throw new ArgumentNullException("controllerContext");
}
if (bindingContext == null) {
throw new ArgumentNullException("bindingContext");
}
HttpPostedFileBase theFile = controllerContext.HttpContext.Request.Files[bindingContext.ModelName];
return ChooseFileOrNull(theFile);
}
// helper that returns the original file if there was content uploaded, null if empty
internal static HttpPostedFileBase ChooseFileOrNull(HttpPostedFileBase rawFile) {
// case 1: there was no <input type="file" ... /> element in the post
if (rawFile == null) {
return null;
}
// case 2: there was an <input type="file" ... /> element in the post, but it was left blank
if (rawFile.ContentLength == 0 && String.IsNullOrEmpty(rawFile.FileName)) {
return null;
}
// case 3: the file was posted
return rawFile;
}
}
}
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