File uploading from a form with textbox form elements

  • Thread starter Thread starter Andy Johns
  • Start date Start date
A

Andy Johns

I've seen plenty of examples of file uploads in ASP.NET when the only
form element is the file input type, but I've not seen a practical
example of a file upload routine running alongside other form
elements, e.g. a text box for a description for example. If the form
is being posted in multipart format then the text coming through will
need to be converted first, won't it?

The other issue is that if the form is posted, and the validation
checks are performed server-side (as they should be, even if you ARE
using client-side checking) won't the form take ages to process due to
the file being transferred in the form data?

I wondered if the webmail style of attachment would be best...where
you popup a window with a form, you attach the file, you upload it,
and then all that appears in the original form is a filename. But
this would mean that the file is already on the server, before you
actually submit the rest of the form contents, so if they then decide
to cancel the form, there'll be an orphaned file.

Is there another way to solve this problem?
 
What I did for a file management sub-system was this:

I have an aspx page that takes (in the query string) the number of files to
upload. I have an <input type=file> for each of these files, as well as
input controls that allow you to fill in several attributes of the file,
such as a description and other attributes relevant to the application.

I furthermore have a web service that stores a link to this file, as well as
an array of names and an equivalent array of values, which form the name
value pairs. I make a call to the web service to store the link to this
document, as well as all of the name value pairs.

The aspx page then simply needs to save the file, and then call the web
service with the location where it saved it and the name value pairs.

Later, when I want to view the files, I can query the web service for all
files with a given name value pair, and it returns that result as a dataset
which I can display on the form.

Doing it this way also enables me to use these attachments from any
application that I want to. All I have to do is give the web service the
name value pair I want to search by, and it returns the list of documents
and their locations, as well as the other friendly descriptions I include.

If you want to display on the fly, and get real data (rather than assumed
data) you could use this solution as well. You can call the web service on
the client side (using MSXML) to get the list of documents that are
relevant, and then you will only see what you have actually finished putting
up there, rather than assuming that calling this second page means the
document is there. When you close the window, you can call a method on the
parent page that re-fetches the list of documents from the server using web
services.
 
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