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Re: [MathML3-last-call] comments from HTML WG

From: Joe D Williams <joedwil@earthlink.net>
Date: Sat, 7 Nov 2009 02:52:33 -0800
Message-ID: <61ABABE19B864AB69B08E193948A8322@joe1446a4150a8>
To: "Shelley Powers" <shelley.just@gmail.com>, <www-math@w3.org>
Cc: "HTMLWG WG" <public-html@w3.org>
Great report, Shelley.
The group and editor were very receptive.
I would expect to get comments on these comments.
Thanks Again and Best Regards,
Joe

----- Original Message ----- 
From: "Shelley Powers" <shelley.just@gmail.com>
To: <www-math@w3.org>
Cc: "HTMLWG WG" <public-html@w3.org>
Sent: Friday, November 06, 2009 7:18 AM
Subject: [MathML3-last-call] comments from HTML WG


> Following are some general comments about the MathML 3.0 draft from
> the HTML WG, particularly as the MathML specification relates to
> current effort with HTML5.  First, though, we wish to extend to the
> Math WG congratulations for reaching this important milestone.
>
> Related to the addition of the new href attribute[1]:
>
> 1. The attribute href has been added for use with several MathML
> elements, rather than using xlink:href, from MathML 2.0. However, 
> the
> document states that because of compound document requirements,
> xlink:href can still be used. This could cause confusion when 
> viewing
> the documentation for  MathML as foreign object in HTML5. In the 
> HTML5
> specification, if the href attribute is associated with the XLink
> namespace, it must be given as xlink:href in the document.
>
> The MathML href attribute is now, by default, associated with the
> MathML namespace. But this isn't specifically stated in the 
> document,
> and someone reading both may become confused, and assume they have 
> to
> use xlink:href with MathML embedded in HTML5. The document may want 
> to
> demonstrate how href can be used with embedded MathML in the 
> document
> section detailing MathML embedded in HTML.
>
> 2. Is the plan to drop support for xlink:href in MathML UAs at some
> point? If not, we're curious as to why the Math WG introduced the 
> new
> attribute?
>
> 3. If the UA supports both, what should happen when both are 
> specified
> on one element?
>
> 4. We're also curious as to why the new href attribute takes a URI
> rather than IRI?
>
>
> Related to the Chapter 6.4, Combining MathML and Other Formats, and
> specific to 6.4.1, Mixing MathML and HTML:
>
> 5. The specification includes a section discussing MathML and HTML.
> However, the section only references MathML in XHTML. With HTML5,
> MathML can be used in HTML, and there are additional constraints on
> using MathML in HTML, including the fact that the outer math element
> is specified without a prefix (such as m:math, as shown in the
> example), though the use of a namespace and prefix can work with
> XHTML.
>
> There are other constraints associated with MathML in HTML. Could 
> this
> one section be split in two, with one section detailing MathML in
> XHTML, and one in HTML?
>
> In particular, HTML allows unquoted attributes, and elements without
> closing tags (if such are given in the list of allowed elements
> without closing tags). These looser specifications also apply to
> foreign
> objects such as SVG and MathML (though user agents are encouraged to
> provide an export facility providing properly formatted XML). 
> However,
> people can paste properly formatted XML into HTML, and it will be 
> supported.
>
> Pasting MathML into HTML does lead to another issue: the use of
> namespaced attributes. Namespaced attributes can be included in
> MathML, but, currently, the validator does provide a warning for
> namespaced attributes in SVG or MathML when embedded in HTML. The 
> same
> applies to properly formatted XML entities and attributes that might
> be included within the MathML annotation-xml
> element.
>
> In addition, there are also, currently, DOM namespace handling
> differences associated with MathML pasted into HTML, as compared to
> MathML pasted into XHTML.
>
> Both the DOM differences and the validator warnings, in addition to
> the syntax differences, such as unquoted attribute values, might be
> surprising and confusing to folks who expect properly formatted XML 
> in
> HTML.
>
> 6. The section contains the following passage:
>
> "To fully integrate MathML into XHTML, it should be possible not 
> only
> to embed MathML in XHTML, as described in Section 6.2.1 Recognizing
> MathML in XML, but also to embed XHTML in MathML. However, the 
> problem
> of supporting XHTML in MathML presents many difficulties. Therefore,
> at present, the MathML specification does not allow XHTML elements
> within a MathML expression, although this situation may be subject 
> to
> change in a future revision of MathML."
>
> What are the difficulties referenced in the document?
>
> In particular, the HTML5 parser supports HTML and SVG in <mi>, <mo>,
> <mn>, <ms>, <mtext> and SVG in <annotation-xml>. XHTML and SVG in
> MathML in these places works fine in Firefox and Opera today when
> using application/xhtml+xml. We're curious as to why MathML doesn't
> allow what is, at a minimum, expressible in text/html?
>
>
> Other, general comments:
>
> 7. In the element listing [2] you show an element labeled td, but 
> the
> link associated with it leads to a section describing an element
> labeled mtd. Possible typo?
>
> 8. In the section describing color[3] you reference color names from
> HTML4. Is there a reason MathML doesn't use css3-color SVG color
> keywords instead of HTML4 color keywords?
>
> 9. The index lists two values, my:background and my:color, which are
> also demonstrated in the section to which they're linked. These 
> would
> seem to be from demonstrations of bringing in color or background 
> from
> another namespace. Including them in the index could generate
> confusion.
>
> Shelley Powers
> HTML WG
>
> [1] 
> http://www.w3.org/TR/2009/WD-MathML3-20090924/chapter2.html#fund.globatt
> [2] 
> http://www.w3.org/TR/2009/WD-MathML3-20090924/appendixh.html#index.elem
> [3] 
> http://www.w3.org/TR/2009/WD-MathML3-20090924/chapter2.html#type.color
> 
Received on Saturday, 7 November 2009 10:53:18 GMT

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