Develop Reference

When are the parameters used in WebResource.axd reset?

When using WebResource.axd you will see two parameters being passed in the query string. Usually looks something like this:
WebResource.axd?d=9H3mkymBtDwEocEoKm-S4A2&t=634093400273197793
I have run into an issue where I need a permanent link to the resource in question. Recently the link I was using stopped working. What would cause these ids to change? Rebooting the server? Recompiling the code? Is there anyway to make these ids permanent?
Background -
As part of a site monitoring service we are subscribed to, we have "recorded" several sets of user actions for our website. For example, we recorded the process of logging into the site. The monitoring is now saying that the user login process fails (it's working fine) because it cannot find the WebResource.axd with the ids it recorded.

This page provides all the information on the makeup of the URL
http://support.microsoft.com/kb/910442
The "d" stands for the requested Web Resource
Something worth noting is that you don't need to have the timestamp (t) parameter there to call the resource. Try it on your own site, view the source and grab a webresource.axd url and navigate to the it, remove the t

URL shortener using c#

I would like to shorten a url (e.g. http://www.abc.com/products/bag.aspx) to something like (http://short.me/bag). I have found that rules can be added to web.config to detect the short link to open the correct page. But I need a dynamic web.config. Is it a good idea to keep updating the web.config whenever a user creates the short url? Or is there a better way to do it?
I have tried YOURLS, RewriteRule, etc. All don't seems to work properly on my server. I am using a WIN server. I don't really want to use the bitly API as I would like to have my own domain in front of the link. Or is there a way to use the bitly API and still retaining my domain name?
Thank you.

You need to create a database mapping short URLs to long URLs.
You would then create an HTTP handler that looks up the short URL in that database and redirects to the corresponding long URL.
Then, register that handler to run for all requests.

Bit.ly lets you use custom domain names now: https://bitly.com/pro/products, check out this part of their FAQ

Getting text after URL in asp.net / URL Rewriting (sort of!)

My app is a very simple "one page" type app-
It has Default.aspx
I'm basically trying to get, for example:
www.myappurl.com/this is my text
I want to get hold of "this is my text" from the above example.
This will be displayed on the page (for now)
I didn't really want to have to use any complext url rewriting things for this...
(My hosting provider uses IIS6)
I tried using a 404 handler, but this is a bit long winded, and i'm using shared hosting, that can't set the "execute url" on custom 404 pages.
Any other ideas?

You can add a mapping for all requests with the * extension to the ASP.NET isapi dll (GET/POST) verbs. You will need to uncheck the "verify file is on disk" checkbox when mapping the extension in IIS. (In IIS7 integrated mode, you map the extension in the web.config as well). Note that this will caause everything to be served by asp.net, even images and script files, which can slow things down.
Then create a handler mapping in your web.config to a http handler you create.
From there, in the ProcessRequest() method of the handler, you have access to the HttpContext that spawned the request and can manipulate the URL from there.
That is the easiest option, you could also create a HttpModule, or have the default page at root redirect to http://www.domain.com/default.aspx/this is my text, in the code-behind of default.aspx, you will be able to get the text following the page and slash.

How to write a global redirect in C#?

A client has sent out an email with a link containging a typo for a website we run [E.g. http://example.com/?id=123.]. What is the best way to re-direct anyone who visits the bad URL?
If someone clicks on the link, can we catch it in the Global.asax, checking if the path ends with "." then removing it and re-directing? If so, where in Global should it be?
If another method is better I'm happy to hear it; the most important thing is speed as this is needs to be nipped in the bud ASAP!

Its not the best solution, but you could use Application_BeginRequest in the global.asax file.
And better way if you are using IIS 7.0 is URL Rewriting

You need to use something like ISAPI_REWRITE for url re-writing in IIS (If IIS 6) because I'm not sure that that request would even be handled by .NET with that extension

If you happen to not have IIS 7.0 you can always use ISAPI_Rewrite (the free edition). Working mainly on regex you can redirect or rewrite any url.
http://www.helicontech.com/isapi_rewrite/

Using a custom URL rewriter, IIS6, and urls with .htm, .html, etc

I have a custom site I'm building with automatic url rewriting using a custom engine. The rewriting works fine as long as the page url doesn't end in somehting like .htm or .html. For these pages it goes directly to the iis 404 page instead of hitting my rewriting engine first.
I have the * wildcard handler in the "Home Directory" section of the IIS6 configuration of that website but these urls seem to be ignored by it (altho things like css, jpg, js, etc to get sent to the url handler in my web project). How do i set up IIS6 to force these urls to get sent to the handler, while still serving the page if it exists normally?
The handler basically does this
if (!File.Exists(Request.Path))
{
doMyRewriting();
}
I have to assume that using a block like this (just and example, the real one does some other stuff to format the Request.Path to be proper with everything) should run the "doMyRewriting()" if the requested file does not exist otherwise it will serve the page normally. Am I mistaken?
If I tell IIS specifically to send .htm and .html pages thru to the .NET handler the rewriting works but if the page is actually there it will not serve it.
Any help would be greatly appreciated.
Thanks in advance!

Don't know if you can or would want to do this, but there is the Ionics Isapi url rewriter you can use.
http://www.codeplex.com/IIRF
Basically install that then set a rule to remove the .html that way it hits your rewrite engine. I use it on IIS 6 with several of my blogs.

I think if you are having IIS send all requests to .NET and your handler, then your handler will need to detect if the page exists and serve it instead of rewriting.
UrlRewriting.NET has an option to do this - you might want to look at their code to see how they're handling this case.

In my opinion, rewriting URLs with IIS 6 is best handled with an ISAPI filter written as unmanaged native code. Otherwise, you run into the issues you've mentioned - having to map all extensions to ASP.Net and losing the ability for simple file handling. With an ISAPI filter, you can choose to not rewrite some URLs and let IIS handle them as normal.
To get started, I suggest reading the ISAPI Filter Overview on MSDN.
If your filter absolutely needs the .Net framework runtime, it is possible to write a small ISAPI filter shell that hosts the CLR and forwards the requests to some managed code. The Filter.Net Framework takes this approach and may be suitable for your needs. There is the small drawback to this approach in that you will have to use the same .Net version as any ASP.Net applications that are run in the main IIS process.