Dear SYMM WG-
This is a Last Call review comment from the SVG WG on the SMIL
Timesheets 1.0 specification, W3C Working Draft 10 January 2008,
http://www.w3.org/TR/2008/WD-timesheets-20080110/ . Please let us know
if you have any questions by replying to email@example.com.
This specification shouldn't define the semantics of how a host
languages references the timesheet. (Option, neither would be defined
outside either document, in a manifest. , but optionally may be defined
by the host language.
While it's good to provide well-defined examples for a host language to
consider, these definitions should be a MAY or RECOMMENDED, or be
informative, not normative.
Please define what happens when multiple timesheets interact, such as
when several timesheets are referenced from the same document.
Can a timesheet import or reference another timesheet, to allow modular
timesheets and reuse? If not, why not? If so, what are the
implications for the timelines?
4.1 The timesheet element
"The timesheet element is located in the head section of the document.
It defines a parent container for other SMIL Timesheet elements."
Please change this to allow the host language to define that "head
section". In SVG there's no "head" element, the closest thing is
<defs>, which can occur any number of times anywhere in the document.
A better definition would be to say that the <timesheet> element can
occur anywhere that the <style> element can. It may be that host
languages will want to define this further though, especially in the
cases where there is no <style> element, so please allow for that too.
"The timesheet element defines two attributes: src and media."
This makes it stand out in SVG, since SVG uses xlink:href for other
"The src attribute tells the location of an external timesheet. With
this attribute a common timesheet can be reused in multiple documents.
The attribute must contain a valid URI."
What happens if the timesheet element has no src attribute? What
happens if the attribute contains an invalid URI? What is a valid URI in
this context? Please add a normative reference to "valid URI".
Why is there no example and spec definition for how to use
<?xml-stylesheet?> for including a SMIL Timesheet? Please add that.
We don't see the need for having the src attribute on <timesheet> given
that <?xml-stylesheet?> can be used instead, and since the
<smil:timesheet> is limited to referencing SMIL Timesheets it's not
re-usable for other types of stylesheets. Please consider removing the
src attribute altogether. In HTML the <link> element might be used
instead, see http://www.w3.org/TR/html401/struct/links.html#edef-LINK.
"The media attribute is used for selecting the most suitable timesheet
for the current media device."
That's informative, make it clear.
"It works in the same way as the @media rule in the CSS stylesheets [CSS2]."
If that's a normative statement please reword it to say it MUST be
exactly as defined in CSS2.
"The media attribute contains a comma separated list of CSS media types."
Informative or normative? Is that not defined in CSS2?
"The timesheet timing and animation information is applied to the host
language document, only when the target device media type matches one of
the media types defined by the media attribute. If the media attribute
isnot defined, the default value is "all"."
Normative? Again isn't this defined in CSS2?
"The timesheet element contains the par, seq, and excl time containers."
What happens when it contains something else? For example if it was to
contain one of SVG's declarative animation elements?
"The semantics and restrictions are specified in the the time container
Semantics and restrictions of what? The timesheet element or the par,
seq, and excl elements? Please clarify.
"In addition, it contains the item and prefetch elements. Finally, it
also contains the animation elements: animate, set, animateMotion,
Umm, why not list all of the elements allowed in one sentence? This is
simply confusing. Please allow the host language to extend the elements
allowed. In SVG there's the <animateTransform> element which is very
useful to include here.
Please explain what should happen when a timesheet is in conflict with a
host language animation? Also if another SMIL animation being applied on
the same element that is animated by a timesheet - how do they interact?
-Doug Schepers, on behalf of the SVG WG