HTTPHandler in VB.net for uploading files using Plupload - sql-server

Question

I have built working VB.net code that uploads multiple images to the server using Plupload. I am using an HTTPHandler (FileUpload.ashx) to do the uplading and want to add a SQL Statement that will insert each of the images File Names to my SQL Database. I have tried just adding the SQL to the Handler, but when I do I get 4 database entries for each iamge that is uploaded. I really dont understand why and need some guidance. Thanks for your time in advance.
Pertainant HANDLER code:
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim chunk As Integer = If(context.Request("chunk") IsNot Nothing, Integer.Parse(context.Request("chunk")), 0)
Dim fileName As String = If(context.Request("name") IsNot Nothing, context.Request("name"), String.Empty)
Dim fileUpload As HttpPostedFile = context.Request.Files(0)
Dim uploadPath = context.Server.MapPath("Upload")
Using fs = New FileStream(Path.Combine(uploadPath, fileName), If(chunk = 0, FileMode.Create, FileMode.Append))
Dim buffer = New Byte(fileUpload.InputStream.Length - 1) {}
fileUpload.InputStream.Read(buffer, 0, buffer.Length)
fs.Write(buffer, 0, buffer.Length)
End Using
context.Response.ContentType = "text/plain"
context.Response.Write("Success")
EXP: SQL insert
Dim conn As SqlClient.SqlConnection = New SqlClient.SqlConnection(DBCONN)
Dim command As SqlClient.SqlCommand = New SqlClient.SqlCommand("W2_InsertPhoto " & fileName, conn)
Dim rs As SqlClient.SqlDataReader
conn.Open()
rs = command.ExecuteReader()
rs.Close()
rs = Nothing
conn.Close()
conn = Nothing

Answer 1

If you are using chunks then make sure that you fire your SQL aster the last chunk has been saved
For example.
chunk = If(context.Request("chunk") IsNot Nothing, Integer.Parse(context.Request("chunk")), 0)
chunks = If(context.Request("chunks") IsNot Nothing, Integer.Parse(context.Request("chunks")) - 1, 0)
If (chunk = chunks) Then
'Upload is complete, Save to DB here or whatever
end if
-1 is used on CHUNKS because chunks is -1 from the last chunk, if that makes sense.
To get the file name all you need to add in your handler.ashx is..
fileName = If(context.Request("name") IsNot Nothing, context.Request("name"), String.Empty)
In order to get unique fileName from Pluplaod across to your handler, you need to tell Plupload(on the client) to use unique names.
var uploader = new plupload.Uploader({
runtimes: 'html5,flash,silverlight,html4',
max_file_size: '20mb',
url: '../handler.ashx',
chunk_size: '100kb',
unique_names: true,
multipart_params: { imageType: $('#myDiv').attr("MyIMageType"), custom: 'This is static custom text' },
In your handler you call the 'name' request again and you will have the unqie names that pluplaoder made.. also to request the data in the multipart you do as usual request
PictureType = If(context.Request("imageType") IsNot Nothing, [Enum].Parse(GetType(PictureType), context.Request("imageType")), Nothing)
Dim myCustom as String = If(context.Request("custom") IsNot Nothing, context.Request("custom"))
In response to your SQL you need to encapsulate the file name withing ' otherwise spaces and special characters will break the SQLCommand, because SQL will think its another variable or command instead of treating it purely as a string. This is also a common problem for SQL Injection.. Allowing hackers to inject code because of code like this.

Answer 2

ppumpkin, I dont think I am explaining myself well. Sorry for what I am sure is lamens terms, I am new to plupload and handlers all at the same time.
I am using unique naming as "false" because I need to retain the original name of each file. I am currently naming the filenames correctly on upload to server, but for my SQL insert I need those same names inserted. If I try and use the FileName that I declared (context.Request("name")) as a value in my SQL Statement I immediately get an error and no inserted value. If I use a static value for filename just to test, it inserts just fine, but of course its the same name for each file I upload.
Including your updates, this what I currently have for my handler and clients script.
Handler:
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
Dim chunk As Integer = If(context.Request("chunk") IsNot Nothing, Integer.Parse(context.Request("chunk")), 0)
Dim chunks As Integer = If(context.Request("chunks") IsNot Nothing, Integer.Parse(context.Request("chunks")) - 1, 0)
Dim fileName As String = If(context.Request("name") IsNot Nothing, context.Request("name"), String.Empty)
If (chunk = chunks) Then
Dim conn As SqlClient.SqlConnection = New SqlClient.SqlConnection(mdata.DBCONN)
Dim command As SqlClient.SqlCommand = New SqlClient.SqlCommand("W2_InsertPhoto 12345," & **fileName**, conn)
Dim rs As SqlClient.SqlDataReader
conn.Open()
rs = command.ExecuteReader()
rs.Close()
rs = Nothing
conn.Close()
conn = Nothing
End If
Dim fileUpload As HttpPostedFile = context.Request.Files(0)
Dim uploadPath = context.Server.MapPath("Upload")
Using fs = New FileStream(Path.Combine(uploadPath, fileName), If(chunk = 0, FileMode.Create, FileMode.Append))
Dim buffer = New Byte(fileUpload.InputStream.Length - 1) {}
fileUpload.InputStream.Read(buffer, 0, buffer.Length)
fs.Write(buffer, 0, buffer.Length)
End Using
End Sub
My client Script:
<script type="text/javascript">
// Convert divs to queue widgets when the DOM is ready
$(function () {
$("#uploader").pluploadQueue({
// General settings,silverlight,browserplus,html5gears,
runtimes: 'flash',
url: 'FileUpload.ashx',
max_file_size: '10mb',
chunk_size: '1mb',
unique_names: false,
// Specify what files to browse for
filters: [{ title: "Image files", extensions: "jpg,jpeg,gif,png,bmp"}],
// Flash settings
flash_swf_url: 'assets/resources/plupload.flash.swf',
// Silverlight settings
silverlight_xap_url: 'assets/resources/plupload.silverlight.xap',
init: {
FileUploaded: function (up, file, info) {
}
}
});
// Client side form validation
$('form').submit(function (e) {
var uploader = $('#uploader').pluploadQueue();
// Validate number of uploaded files
if (uploader.total.uploaded == 0) {
// Files in queue upload them first
if (uploader.files.length > 0) {
// When all files are uploaded submit form
uploader.bind('UploadProgress', function () {
if (uploader.total.uploaded == uploader.files.length)
$('form').submit();
});
uploader.start();
} else
alert('You must at least upload one file.');
e.preventDefault();
}
});
//tweak to reset the interface for new file upload
$('#btnReset').click(function () {
var uploader = $('#uploader').pluploadQueue();
//clear files object
uploader.files.length = 0;
$('div.plupload_buttons').css('display', 'block');
$('span.plupload_upload_status').html('');
$('span.plupload_upload_status').css('display', 'none');
$('a.plupload_start').addClass('plupload_disabled');
//resetting the flash container css property
$('.flash').css({
position: 'absolute', top: '292px',
background: 'none repeat scroll 0% 0% transparent',
width: '77px',
height: '22px',
left: '16px'
});
//clear the upload list
$('#uploader_filelist li').each(function (idx, val) {
$(val).remove();
});
});
});
</script>