- From: Jason White <jasonw@ariel.its.unimelb.edu.au>
- Date: Thu, 9 Feb 2006 18:30:32 +1100
- To: w3c-wai-gl@w3.org
On Wed, Feb 08, 2006 at 03:23:45PM -0600, Gregg Vanderheiden wrote: > Web Unit (e.g. Page) > > > A collection of information, consisting of one or more resources, > intended to be rendered together, and identified by a single Uniform > Resource Identifier (URLs etc.). Amend the end of the sentence as follows "single Uniform Resource Identifier (URI)". I raised a number of problems with the definition of "delivery unit" in public comments relative to the November 2005 working draft. I think this latest definition by Gregg and John addresses many of those comments but would need to check in detail to confirm this. A few remarks that come immediately to mind: 1. The proposal can be read as implying that the URI identifies the entire collection of resources. However, I thought it was part of the definition of a URI that it refers to exactly one resource only. Maybe the definition should be something along these lines: "A collection of Web resources intended to be rendred together. A Web unit consists of one primary resource and may include one or more secondary resources. To identify a Web unit it is sufficient, for purposes of these guidelines, to specify the URI of its primary resource. Note: the primary resource is typically the first component of the Web unit retrieved by a user agent for the purpose of rendering the Web unit." 2. A further question relates to how this proposal, with or without my clarifications, affects resources that refer to alternative forms of content. Suppose I write an XHTML document containing three nested OBJECT elements: the outermost OBJECT refers to an animation; inside this is a second OBJECT element referring to an image, and nested within this a third OBJECT element containing a hypertext link to a detailed description. The animation and the image are not intended to be "rendered together", because they are alternatives to each other. Since the description is referred to via a hypertext link, I suppose one could say that it isn't intended to be rendered with the XHTML document, so it isn't part of the same WEb unit. I'm not sure whether that's a problem for conformance purposes; it might mean that the entity claiming conformance has to be careful to ensure that both the XHTML document and the description are within the scope of the claim. This would require a URI pattern or the specification of both URI's in the conformance claim. That the definition can't tell us whether either or both of the animation and the image should be counted as part of the Web unit could be a problem, however. (Suppose e.g., that one of them violates guideline 2.3). It might be necessary to say something similar to the following. A WEb unit consists of: 1. A primary resource. 2. All resources intended to be rendered, either collectively or in any combination, with the primary resource. I hope these comments are helpful.
Received on Thursday, 9 February 2006 07:30:46 UTC