I'm writing a small asp.net program used to log information whenever some pdf files is accessed. I use httpmodle to achieve that. But the problem is if the pdf file is big (>1M or so), more than one PreRequestHandlerExecute events will be raised (if I download the file, only one event will be raised). These pdf files belong to another web app. If possible, I don't want to touch that app. Any suggestions appreciated.
Depending on the information you are logging you might be able to save yourself some work just by parsing the server log files using something like Log Parser.
Thank you. I ever used log parser to do it, but I found it is not suitable for my case. IIS will not write the information to its log file immediately.
Here what I don't understand is why asking a pdf from server will trigger PreRequestHandlerExecute several times. And it seems that bigger the file more events was raised.
After checking the log file of IIS I found there are several log records for the same pdf request. So...
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As I understand it, when a link to a file is clicked in the browser, the file is silently downloaded to a temporary directory on the computer. Then the prompt is displayed which shows Open, Save, Cancel... Then if the user clicks Save, they are prompted to save it somewhere, and finally the file is basically transferred to that location when confirmed.
Assuming that is correct, I'm looking for a way to determine if the user actually downloaded the file. So basically determine if they clicked the Save button.
The bit of research that I've done leads me to believe this is not possible, because there is no standardized way of capturing that event, however I could be wrong. And the only possible solution I can come up with is to create an actual client application. Any thoughts on that?
Also, if there are any other off the wall ideas, I'm open to those as well.
And in case it makes a difference, I'm working within an ASP.NET environment.
How about turning this whole problem around and audit the file that actually being downloaded. You can turn on file/folder auditing and capture onlyt the success and failures of the IIS process. Then correlate the audit event with the pieces parts in the IIS log to get the particulars of who actually downloaded the file.
Just my $0.02 YMMV
Yes, I'm still using Classic ASP.
I'm about to write a script that checks a directory on the server, every 5 minutes, for newly uploaded photos, by my office, and to transfer the photos to another location. I'm using ASP and the FileSystemObject as the application and a Windows Schedule calls it.
What I would like to know is: If the user is sending 150 photos, by FTP, my application is not going to know if the user has finished uploading, or not. So then the application will go through the files one-by-one and transfer them. If my user has a slower connection than the speed of my application, the script may eventually come across the file that is currently being uploaded...
Will my application grab that file thinking it's complete or will it know that it's in the middle of upload and leave it alone? If it DOES grab it and transfers half a photo, how can I stop this from happening?
There is no good way to test for that, much depends on how the uploader is working.
Its highly unlikely that a file currently open for write access while the uploader creates it is going to allow your code to move it. An attempt to move it will result in a sharing violation or similar error. So protecting that section of code with an On Error Resume Next would do it. Have your code skip that file in the knowledge that it will be picked up again when the next poll comes round.
Background: I am creating a multi-language web application using Flash-builder 4. The menus and text used are being populated through an external XML file. I have different XML files for different languages.
Problem: When the user changes the language the XML file takes some time to load. As a result the user sees a blank screen for some time and may get the impression that nothing is happening.
During this time I want to display a message informing the user that the file is being loaded. Something like this can be seen at http://gis.foundationcenter.org/worldmap/index.php.
A screen-shot is also uploaded here
Any help or sample code would be appreciated.
Thanks
When user changes the language, compiler has started reading XML file then add waiting module and remove waiting module when last XML file has been read by the compiler.
I need to add a file upload function to an ASP.NET website and would like to be able to read a small portion of the file on the server while it's still uploading. A peek or preview type function so I can determine contents and give some feedback to the user while it is still uploading (we're talking about large files here). Is there any way to do this? I'm thinking worst case of writing a custom control which uploads only a fixed number of bytes of the file once chosen and then under the covers starts another upload of the full file. Not totally sure even this is possible, but I'm looking for a more elegant solution anyway... Thanks!
It sounds like you want to avoid the "white screen of death" during large file uploads. If so, you might want to look into Telerik's RadUpload control , which provides a progress bar during upload.
If you want to roll your own, I'd decompile their trial copy for ideas. I've peeked at their source in this way, and they accomplish the progress bar through a combination of a custom HttpModule and HttpHandler along with their control. The handler routes the file in a streamed fashion while the module provides "percent complete" information--or the other way round; it's been a few years since I looked at it.
Edit:
Actually, I'm trying to do server-side processing as the file is still being uploaded. I want to import user data via HTTP, but want to present the user with preview/options of how we'll process their data while the file is still uploading (column definitions, etc.). No matter what, we'll take the file as is, so the upload doesn't need to be interrupted. Given that I actually want interaction during the upload based on reading a relatively small portion of the file as it is being uploaded, would you still recommend the same approach?
Well... it'd be very difficult to do, and it might not work cross-browser, but it could be done with this approach.
Since it's entirely possible to work with the incoming file as a stream as I mentioned, you could have your intial processing update some state as part of that stream processing. If you don't process as a stream, you have to wait for the full file upload before you can do anything with it.
The problem is this: during the file upload, you cannot have any more HTML-based interaction. The post must continue unabated or the upload will fail. The control I linked only works at all because most browsers allow javascript to continue to execute and update page DOM during the post.
So in order to make this work, you have to update some standardized state server-side during your file processing in the HttpModule, which is transmitted back to the client via XmlHttpRequest calls handled by the HttpHandler. You have to use pure javascript/DOM to update the UI for the user.
So, as I said, it's complex and likely to be buggy cross-browser, but it could theoretically be done.
There are alernatives that might be more stable, but might not necessarily be feasible: you could build an ActiveX control or a Click-Once .NET application that pre-processes the file before upload, and maybe even asynchronously transfers the file while the user continues browsing. Some users may not like that option, and I don't know the particulars of your deployment scenario, but it's an option.
There is an HTTP HEAD method but not PEEK.
HEAD will give you information and headers about the file.
Of course you can make a special request handler that does anything you want. You don't have to work with static resources, you can dynamically create any response you want.
I've got a grid which provides some links for users to download files. Files are stored outside of the application, the path references are read from the database and a HTTP handler (*.ashx) is used to serve each requested file. It is, however, possible that there could be a database entry pointing to a non existent file. I catch the FileNotFoundException, but I'm not sure what would be the best method to inform the user of the missing file (so that they can contact support).
First idea is to set a standard 404 code on the response, and that's what I'm doing now.
A more helpful way would be to display a notification (jQuery) about a missing file, but the file download is not done in AJAX, so this would involve a two step process - a client side onclick handler calls a web service method to check if the file exists, if not, then I cancel the click (return false) and display a friendly message to the user. If the file exists however, I proceed with the normal execution. But this adds yet another server call.
Have you dealt with a similar problem? How did you solve it?
Some clarifications - the application is built in ASP.NET 2.0 and uses jQuery to call the web service methods.
Pawel, it seems you've answered your question already...
...(so that they can contact
support)...
By stating the above I would suggest you create a custom 404 page which notifies the user of the file not existing on disk and provide them information on how to get in contact with the support office.
I've created a HTTP Handler for handling files and if a file does not exist on disk then I return a 404 response. I've setup IIS to display a custom page if a 404 reponse has been thrown.. (and I do the same for error 500).
Hope this helps and good luck with finding the solution that fits your needs!