File upload with strongly typed view and model validation

Shailendra Chauhan   Source Code  Print 
09 Jan 2013
13 Sep 2018
Intermediate
167K

Many times, we required to upload file with strongly-typed view and also apply validation on uploading file using data annotation validators. In this article, I would like to share, how can we upload a file and validate that file, firstly at client side and after that at server side.

How to do it..

Step 1 : Designing model with data annotation validation

public class RegistrationModel
{
 [Required(ErrorMessage = "Please Enter Your Full Name")]
 [Display(Name = "Full Name")]
 public string Name { get; set; }
 
 [Required(ErrorMessage = "Please Enter Address")]
 [Display(Name = "Address")]
 [MaxLength(200)]
 public string Address { get; set; }
 
 [Required(ErrorMessage = "Please Upload File")]
 [Display(Name = "Upload File")]
 [ValidateFile]
 public HttpPostedFileBase file { get; set; }
}

//Customized data annotation validator for uploading file
public class ValidateFileAttribute : ValidationAttribute
{
 public override bool IsValid(object value)
 {
 int MaxContentLength = 1024 * 1024 * 3; //3 MB
 string[] AllowedFileExtensions = new string[] { ".jpg", ".gif", ".png", ".pdf" };
 
 var file = value as HttpPostedFileBase;
 
 if (file == null)
 return false;
 else if (!AllowedFileExtensions.Contains(file.FileName.Substring(file.FileName.LastIndexOf('.'))))
 {
 ErrorMessage = "Please upload Your Photo of type: " + string.Join(", ", AllowedFileExtensions);
 return false;
 }
 else if (file.ContentLength > MaxContentLength)
 {
 ErrorMessage = "Your Photo is too large, maximum allowed size is : " + (MaxContentLength / 1024).ToString() + "MB";
 return false;
 }
 else
 return true;
 }
}

Step 2 : Designing view based on model

<h2>File upload with model validation</h2>
<h3 style="color: green">@ViewBag.Message</h3>

@using (Html.BeginForm("FileUpload", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{ 
 <fieldset>
 <legend></legend>
 <ol>
 <li>
 @Html.LabelFor(m => m.Name)
 @Html.TextBoxFor(m => m.Name, new { maxlength = 50 })
 @Html.ValidationMessageFor(m => m.Name)
 </li>
 <li>
 @Html.LabelFor(m => m.Address)
 @Html.TextAreaFor(m => m.Address, new { maxlength = 200 })
 @Html.ValidationMessageFor(m => m.Address)
 </li>
 <li class="lifile">
 @Html.TextBoxFor(m => m.file, new { type = "file" })
 @Html.ValidationMessageFor(m => m.file)
 </li>
 </ol>
 <input type="submit" value="Submit" />
 </fieldset>
}

Step 3 : Applying jQuery validation for validating file

<script type="text/jscript">
//get file size
function GetFileSize(fileid) {
 try {
 var fileSize = 0;
 //for IE
 if ($.browser.msie) {
 //before making an object of ActiveXObject, 
 //please make sure ActiveX is enabled in your IE browser
 var objFSO = new ActiveXObject("Scripting.FileSystemObject"); var filePath = $("#" + fileid)[0].value;
 var objFile = objFSO.getFile(filePath);
 var fileSize = objFile.size; //size in kb
 fileSize = fileSize / 1048576; //size in mb 
 }
 //for FF, Safari, Opeara and Others
 else {
 fileSize = $("#" + fileid)[0].files[0].size //size in kb
 fileSize = fileSize / 1048576; //size in mb 
 }
 
 return fileSize;
 }
 catch (e) {
 alert("Error is :" + e);
 }
}

//get file path from client system
function getNameFromPath(strFilepath) {
 var objRE = new RegExp(/([^\/\\]+)$/);
 var strName = objRE.exec(strFilepath);
 
 if (strName == null) {
 return null;
 }
 else {
 return strName[0];
 }
}

$(function () {
 $("#file").change(function () {
 var file = getNameFromPath($(this).val());
 if (file != null) {
 var extension = file.substr((file.lastIndexOf('.') + 1));
 switch (extension) {
 case 'jpg':
 case 'png':
 case 'gif':
 case 'pdf':
 flag = true;
 break;
 default:
 flag = false;
 }
 }
 if (flag == false) {
 $(".lifile > span").text("You can upload only jpg,png,gif,pdf extension file");
 return false;
 }
 else {
 var size = GetFileSize('file');
 if (size > 3) {
 $(".lifile > span").text("You can upload file up to 3 MB");
 }
 else {
 $(".lifile > span").text("");
 }
 }
 });
});
</script>

Step 4 : Designing Controller

public ActionResult FileUpload()
{
 return View();
}

[HttpPost]
public ActionResult FileUpload(RegistrationModel mRegister)
{
 //Check server side validation using data annotation
 if (ModelState.IsValid)
 {
 //TO:DO
 var fileName = Path.GetFileName(mRegister.file.FileName);
 var path = Path.Combine(Server.MapPath("~/Content/Upload"), fileName);
 mRegister.file.SaveAs(path);
 ViewBag.Message = "File has been uploaded successfully";
 ModelState.Clear();
 }
 return View();
}

How it works...

What do you think?

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