- From: Chris Lilley <chris@w3.org>
- Date: Tue, 2 Nov 2004 17:22:24 +0100
- To: "L. David Baron" <dbaron@dbaron.org>
- Cc: www-svg@w3.org
On Tuesday, November 2, 2004, 2:05:31 AM, L. wrote: LDB> The media type registration [1] for image/svg+xml should be changed so LDB> that a conformant image/svg+xml processor must not treat XML elements LDB> that are in no namespace as though they were in the SVG namespace. I don't see that such a statement belongs in the media type registration template. I agree that the statement needs to be in the spec. LDB> Omission of namespaces seems to be a common authoring mistake in SVG on LDB> the Web, for example [2], which suggests that this is a common mistake LDB> in existing SVG implementations. Such documents are not conformant SVG LDB> documents because of: LDB> * the "an SVG namespace declaration must be provided" requirement in [3], and LDB> * because of the validity test in [5] (which would attempt to validate LDB> a document with no root element, since no elements are in the SVG LDB> namespace). Yes. LDB> The SVG 1.1 specification does not define error handling for such LDB> documents. This is perfectly reasonable, since describing the behavior LDB> of elements outside of the SVG namespace is out of scope of the SVG LDB> specification. The SVG 1.1 spec does say what to do with elements outside the SVG namespace; SVG 1.2 does not alter that: http://www.w3.org/TR/SVG11/conform.html#ConformingSVGDocuments G.2 Conforming SVG Document Fragments Note that the result of applying that on the common authoring mistake is an empty document. LDB> However, now that the SVG specification contains a media LDB> type registration, that media type registration should define how to LDB> handle documents that would not otherwise be considered SVG when sent LDB> using the registered media type. (I believe the spec already defines this case). LDB> I don't have strong opinions on *how* the registration should forbid LDB> treating the no-namespace elements as SVG. One reasonable way would be LDB> stating that a conformant image/svg+xml processor must abort processing LDB> of any document sent as image/svg+xml unless the root element of that LDB> document is in the "http://www.w3.org/2000/svg" namespace. No, that is undesirable. We have taken care in the SVG spec not to make that assumption; we use the phrase 'root most svg element' and 'svg document fragment' rather than 'root element' and 'document', for example. LDB> I believe LDB> this requirement would be sufficient to bootstrap the error-handling LDB> requirements for unknown elements ([6] and [7]). LDB> -David LDB> [1] http://www.w3.org/TR/2004/WD-SVG12-20041027/mimereg.html LDB> [2] LDB> http://www.w3.org/Consortium/Offices/Presentations/svgs/World.svg LDB> and the external resources it references: LDB> LDB> http://www.w3.org/Consortium/Offices/Presentations/svgs/WorldAS.svgz LDB> LDB> http://www.w3.org/Consortium/Offices/Presentations/svgs/WorldEU.svgz LDB> LDB> http://www.w3.org/Consortium/Offices/Presentations/svgs/WorldUS.svgz LDB> These four files currently use SVG elements with no namespace LDB> prefixes but have no xmlns attribute making the SVG namespace the LDB> default on the root element and have no DOCTYPE declaration that LDB> would introduce such an attribute. LDB> [3] LDB> http://www.w3.org/TR/2003/REC-SVG11-20030114/struct.html#NewDocumentOverview LDB> (Although, for documents that have a DOCTYPE declaration, such as LDB> [4], it is unclear whether this requirement means that the xmlns LDB> declaration must also be explicitly provided.) LDB> [4] http://www.w3.org/2002/05/memberGraph.svgz LDB> [5] LDB> http://www.w3.org/TR/2003/REC-SVG11-20030114/conform.html#ConformingSVGDocuments LDB> [6] LDB> http://www.w3.org/TR/2003/REC-SVG11-20030114/extend.html#PrivateData LDB> [7] LDB> http://www.w3.org/TR/2003/REC-SVG11-20030114/implnote.html#ErrorProcessing -- Chris Lilley mailto:chris@w3.org Chair, W3C SVG Working Group Member, W3C Technical Architecture Group
Received on Tuesday, 2 November 2004 16:22:25 UTC