Re: [web-devel] [Yesod] Re: Yesod: Dynamic subdomains

Great example! Inspired me to post a recipe for re-directing from www to the main domain: http://www.yesodweb.com/show/topic/536 Did the syntax high-lighting stylesheet disappear? The domain-based routing does make me wonder though- in Rack the data structure is a hash instead of a record and I could place the sub-domain somewhere in the hash. Having a reliable record is much nicer than a hash. However, this shows a use-case where we want to save off extra data at the WAI level, but there is no way to do so. It seems like WAI should be modified in some way to properly accommodate this use case. The first thing that comes to my mind is having an extra parameter in the request record that is a Map expressly for the purpose of storing data for later use. What do you think? Greg Weber On Sat, Aug 27, 2011 at 11:09 AM, Michael Snoyman wrote:

On Fri, Aug 26, 2011 at 4:09 PM, "Timo B. Hübel" wrote:

...

Hi,

I am building a Yesod web app which should support dynamic subdomains. I.e. a user registers as "foobar" on http://www.example.com and can afterwards access her content via http://foobar.example.com

Is this possible at all? I am wondering, because the server name is somehow hard coded in Settings.hs as approot.

If it is possible: How do I access the domain name in a handler function?

Thanks! Timo

Hi Timo,

I've put up a cookbook recipe for domain-based routing[1]. It doesn't require checking domain names in the handler function at all, but instead uses the normal routing mechanism in Yesod. As a direct answer to your question, to get access to the domain name, you'll want to get the WAI request value via waiRequest[2] and then lookup the "Host" header in requestHeaders[3].

Let's direct any follow-up discussion to the Yesod mailing list (CCed).

Michael

[1] http://www.yesodweb.com/wiki/Domain-based%20routing [2] http://hackage.haskell.org/packages/archive/yesod-core/0.8.3.2/doc/html/Yeso... [3] http://hackage.haskell.org/packages/archive/wai/0.4.1/doc/html/Network-Wai.h...