How can I give the response file of a universal HTTP request a unique name?

Question

I've developed an HTTP API Server (intended to be called by third-party applications, not necessarily by a web browser) which has one universal call to get (download) any and all types of files by passing a name parameter in the query string for the file requested. All calls, no matter for which file, are handled in the same custom request handler of mine called Get (not to be confused with the standard HTTP get). A query string includes a property name which identifies the unique file to get.

So a request may look like:

http://MyServerURL.com/Get?Key=SomeAPIKeyForAuthentication&Name=SomeUniqueIdentifier

First of all, I know I can obviously make the server fetch a file using only the URI, for example...

http://MyServerURL.com/SomeUniqueIdentifier?Key=SomeAPIKeyForAuthentication

...but the design is specifically meant to use this one universal get command, so I need to keep this unique identifier in the query string. The actual applications which connect to this API will never need to know this filename, but there may be an event when a URL is manually provided for someone to open in their browser to download a file.

However, whenever a file is downloaded through a web browser, since the call is get, the saved filename also winds up being just get.

Is there any trick in HTTP which I can implement on my server which will force the downloaded filename to be the unique identifier, rather than just get? For example, some method such as using re-direct?

I'm using Indy 10 TIdHTTPWebBrokerBridge in Delphi XE2 as the web server. I'm looking for a way in this component (technically in its corresponding TWebModule handler) when it handles this get request, to make the response's filename whatever string I want (in this case, SomeUniqueIdentifier). I've heard the term "URL Re-writing" but that's a rather different topic, and don't think it's what I need, yet it might.

Answer 1

That seems to a rather long winded way of saying you want to set the filename for an HTTP download indpendently of the URL used to fetch it. In which case you simply send a Content-Dispositon header specifying the desired filename. See section 19.5.1 of rfc 2616

e.g.

 Content-Disposition: attachment; filename="stackoverlow.ans"