We have a windows forms legacy asp.net site that uses the AjaxFileUpload control to manage file uploads. One of our issues is that we have different file type uploads but these types are distinguished not by the extension, but by an element right before the extnsion, EG: .gh.zip vs. .gy.zip. It seems that if I add one of these, but not the other, to the AllowedFileTypes, it doesn't allow either. Is it possible to piggyback some additional JS validation code to prevent an invalid file name, or would I need to replace the entire module with something else, and if so, what would be the recommendation for something that's going to be the least time-consuming that will offer a reasonable amount of configuratability?
That control is open source - you can download the source and change it if you wish.
However, why would not just specifying zip as allowed file type work?
If I set a allowed extension of zip?
Then all of these work:
.gh.zip ok
.gy.zip ok
.pdf no
However, my markup is this:
<ajaxToolkit:AjaxFileUpload ID="AjaxFileUpload1" runat="server"
OnClientUploadCompleteAll="MyCompleteAll" ChunkSize="16384"
AllowedFileTypes="zip"
/>
So, above only allows zip files.
if I try to say add a pdf file to above que, then I get this:
So just add allowed extension type = zip
(Edit: do NOT include the "." in this extension)
I not sure why that would not work?
But as noted, you can grab the source - it is open source code now.
However, I suspect perhaps some other issue is going on here?
Or maybe you need "more" complex file extensions parsing?
I mean, you could for the "rare" cases or say some "out liner" cases allow that file up-load, and THEN the post-processing code could reject the file type anyway, right?
However, looking at above, just specify file type = zip, and you should be ok.
Related
I want to make some basic math stuff like Sum in Diagrams.net (old Draw.io).Is it possible ?
Exemple : I create a new parameter on a shape, like "Elec : T16" and make several copy on this shape. Is it possible to have a Text which can give me the total of the shape with this parameter ?
Best Regards.
I search a lot in the Diagrams.net blog but anything relevent.
This is not supported.
Regards,
I also wanted to do something similar and while it doesn't seem possible to do it completely in the software (as of v20.3.0), I did find a bit of a workaround: If you add properties to the shape data, then do File > Export As > XML, the properties will be there in the XML data. You can then count them one of two ways:
Open the XML file with a text editor like Notepad++, do a find on the value you want to count. If you choose "Find All" it will tell you how many times it appears.
Use a programming language like Python to read through the file and count the instances of that value.
Example:
I created a red circle in a new diagram, edited the text to say "RedCircle" and used Edit Data to add a property called TestValue, to which I assigned a value of 1. When I exported to XML it contained this element:
<object label="RedCircle" TestValue="1" id="6byQ5fOap-RXn7mFit_J-1">
Notes
When you export, make sure you turn off the Compressed option, this will create an unusable file.
Don't use Save As > XML, this will also use compression.
Diagrams.net natively saves in a compressed XML format, with only slight differences between that and the other compressed XML options, but it seems happy to also read in the exported uncompressed XML. I didn't test but if you go the programming route and want to take it a step further, it seems you could have the program update the value of a given "counter" element with the count, then open the XML file in diagrams.net to see the updated value and save it as a native .drawio file or publish in whatever format you like.
Edit: I discovered that under File > Properties you can turn off the compression on the actual .drawio file. If you do that you can just work from this file instead of exporting, but you might want to check the size of your file with and without it.
I'm sure a plugin could be created to do all of that within the app itself, but the other methods are enough for me at this point.
Hope this helps you!
I am looping through the posted values on a form with a view to doing something with them (so don't have access to the controls themselves). This is the process I have to take on this project so that is why I'm doing it this way.
On the form I will have a file upload box but I am not sure how I would upload the file that has been selected from it as I can't just do Control.SaveAs(). When I return the posted value using Request.Form.Item[i] I get the file name I chose but not the full path like I would expect.
Can someone point me in the right direction please?
Thanks.
If you want to manipulate the uploaded files directly, and not through a FileUploader control, you should use the Request.Files collection and not the Request.Form
File Upload controls only pass the file name and the contents. I'm not sure why you would need a folder name, especially since the folder name would be for the client - I can't expect that this would have any value to you since you want to save the file on the server.
As I am unsure of your goals, I would recommend using Server.MapPath("~/Folder") to find a suitable folder to save your uploaded files to
I have broken down the horribly unwieldy web.config file into individual files for some of the sections (e.g. connectionStrings, authentication, pages etc.) using the configSource attribute.
This is working fine, but the individual xml files that hold the section 'snippets' cause warnings in VS.
For example, a file named roleManager.config is used for the role manager section, and looks like this:
<roleManager enabled="false">
</rolemanager>
However I get a blue squiggle under the roleManager element in VS, and the following warning: The 'roleManager' element is not declared
I guess this is something to do with valid xml and schemas etc. Is there an easy way to fix this? Something I can add to the individual files?
Thanks
P.S. I have heard that it is bad practice to break the web.config file out like this. But don't really understand why - can anyone illuminate me?
Searching a workaround to this matter using Custom Config Files, I found this solution. Dont know if is the correct one.
The problem is that VS cant find a schema to validate your .config (xml). If you are using "native" configuration elements or when you create your custom .config files you must set to every xml document a schema.
By default (in VS9 for example) all xml files use \Microsoft Visual Studio 9.0\Xml\Schemas\DotNetConfig.xsd
but you can add more schemas to use.
Before assigning a schema you must create it.
To create a new Schema based on your own custom.config:
open your custom config file
in menubar XML->Create Schema
save it
To assign your schema:
open your custom config file
in properties panel: click on the browse button [..]
set the 'Use' column to your recently created schema
you can assign as many you want. or have one schema for all your different custom .config files
(Sorry, but my English is not so good)
I think that you get the blue squiggles since the schema of your web.config file doesn't declare these custom config sections that you've 'broken out' into individual files.
In investigating this, I see that some of my solutions have the same issue, but the config sections that are provided from microsoft DON'T have the squiggles. eg: we have extracted the appsettings and connectionstrings out into their own files, and they don't get the squiggles, but our custom ones do.
I tried to view the microsoft schema at schemas.microsoft.com/.netconfiguration/v2.0, but I get a 404 when trying to download it.
What I'm trying to say is if you get a copy of the MS schema and alter it to include your external config files, you should be able to get rid of the dreaded squiggles!
HTH,
Lance
At the moment i get file extension of the file like :
string fileExt = System.IO.Path.GetExtension(filUpload.FileName);
But if the user change the file extension of the file ( for example user could rename "test.txt" to "test.jpg" ), I can't get the real extension . What's the solution ?
You seem to be asking if you can identify file-type from its content.
Most solutions will indeed attempt the file extension, but there are too many different possible file types to be reliably identifiable.
Most approaches use the first several bytes of the file to determine what they are.
Here is one list, here another.
If you are only worried about text vs binary, see this SO question and answers.
See this SO answer for checking if a file is a JPG - this approach can be extended to use other file headers as in the first two links in this answer.
Whatever the user renames the file extension to, that is the real file extension.
You should never depend on the file extension to tell you what's in the file, since it can be renamed.
See "how can we check file types before uploading them in asp.net?"
There's no way to get the 'real' file extension - the file extension that you get from the filename is the real one. If file content is your concern, you can retrieve the content type using the .ContentType property and verify that it is a content type that you are expecting - eg. image/jpg.
I'm storing some files in my database and since I'm storing them in binary format and not keeping any other information, I have to make sure that all of them are in the same format so that I'll be able to "serve" them later (If there's a simple way to infer the file type from a byte array, please tell, but that's not the focus here).
So, what I need to do is validate every file that is uploaded to make sure it's on the required format.
I've set up a FieldTemplate with a FileUpload control and a CustomValidator:
<asp:FileUpload ID="FileUpload" runat="server" />
<asp:CustomValidator
ID="CustomValidator1"
runat="server"
ErrorMessage="PDF only."
ControlToValidate="FileUpload"
OnServerValidate="CustomValidator1_ServerValidate">
</asp:CustomValidator>
What I'm missing is the code to place in that CustomValidator1_ServerValidate method that checks the uploaded file to make sure it's in the right format (PDF in this case).
Thanks in advance.
Use the FileUpload.PostedFile.ContentType property to validate the MIME type ( should be application/pdf ). For security reasons, also validate that the file extension is appropriate ( .pdf ). You could have a static hashtable containing mappings from MIME type to file extension(s) and use as lookup to validate an extension.
Like ary said. This can all be spoofed. Take a .txt file, rename it to a pdf file and try getting the content type. It will be "application\pdf".
However there is one solution that I have used before. During my brief test with the PDF files, I figured out that the first 3 bytes were always the same. I tried only the first 3 bytes because it seemed enough. The value for the first three bytes is : 37, 80, 68.
So I read the bytes (InputFile1.FileContent.ReadByte()), compared them to the 3 bytes above and if they were the same, then I had a PDF file. Also I read somewhere that you should turn off the script execution for the upload directory in IIS. Hope it helps.
The FileUpload.PostedFile.ContentType was exactly what I was looking for.
Just a heads-up to whoever is trying to do the same thing: it seems that the MIME type for PDF files can be "application/pdf" or "text/pdf", so be sure to check for both.
User can spoof it. In the solution above has no validation of the actual bytes content. I can send you executable and disguise it as pdf and this will not catch it.