- From: Martin J. Duerst <duerst@w3.org>
- Date: Mon, 21 Aug 2000 10:38:08 +0900
- To: "Aaron E. Walsh" <aaron@mantiscorp.com>, uri@w3.org
Hello Aaron, At 00/08/18 17:07 -0400, Aaron E. Walsh wrote: >Hello everyone, > >I've just recently joined the uri@w3.org list, and so apologize in >advance if this subject has been been discussed before (I reviewed the >archives but couldn't find an answer, although I imagine it's been >tacked before). > >I wonder if un-escaped colons are legal in the path portion of a URL so >long as they're not in the scheme or domain? Michael answered this one, yes they are legal (and don't need to be escaped). >For example: > >http://www.web3dmedia.com/urn:web3d:media:/textures/nature/grass_1.jpg >http://www.officetowers.com/urn:web3d:media:/textures/nature/rocks_3.jpg These look definitely like legal URIs. >I ask because our Web3D Universal Media Working Group uses URNs for >media referencing, which we'd like to extend to single URL environments >such as standard HTML browsers and authoring tools (our use of URNs is >based on the VRML97 ISO standard, which supports multiple URLs/URNs). >The two URLs above show how we might embed a URN into a URL so that the >media can be resolved via http (over the net) by products that don't >understand Universal Media (just like a normal URL) while also giving >products that understand our system what they need to know in order to >fetch the media from the user's local system (the URN identifier >"urn:web3d:media:" is the key; this tells Universal Media products that >a piece of media is likely be be locally resident and so they'll attempt >to resolve it locally first before trying the Web). While the syntax is okay, this may not exactly work. The above are http URIs, and the fact that they contain 'urn:web3d:media:' as one of their path components doesn't make any difference. For the HTML browsers, this would work out because they just send a request to www.web3dmedia.com with /urn:web3d:media:..., and www.web3dmedia.com is allowed to treat this in any way it wants (and may even have set up a directory named urn:web3d:media: just to make work easy on the server side). However, the other way round is a bit more difficult. How is VRML software supposed to treat this differently? Looking at the first path component and treating it as an URN if it starts with urn: is definitely wrong; it would go havoc if somebody decided to use something like http://www.example.com/urn:web3d:media, which is a perfectly good straight old http URI. It is of course not forbidden to define such behavior for a single (or a few) well known domain name(s), just as proxy/caching behavior, this may not exactly be what you want (but it may be all you can get). Regards, Martin.
Received on Sunday, 20 August 2000 21:36:25 UTC