[whatwg] [WA1] The profile Attribute
jg307 at cam.ac.uk
Mon Apr 18 06:06:37 PDT 2005
Lachlan Hunt wrote:
> James Graham wrote:
>> <head profile="http://example.com#foo">
>> <profile href="http://example.com#bar" title="bar" />
>> <link rel="comments" href="#comments" />
>> <link rel="license" href="license.html" profile="bar" />
> The problem with that method is that it doesn't allow values from
> multiple profiles to be included within the same element.
Is that an actual problem in practice? With <link /> one can always add
another link element pointing to the same resource. I suppose it's more
of an issue for random elements and class (although I still think using
class is suboptimal).
> Whereas, a solution that adds namespaces more like the following,
> but doesn't require their use to reference the values where it is not
> ambiguous would be better.
> For example, three profiles are defined with each given a namespace
> prefx and contain the listed values.
> Profile 1: foo http://example.org/foo
> Values: a, b, c
> Profile 2: bar http://example.com/bar
> Values: c, d
> Profile 3: baz http://example.net/baz
> Values: d, e, f
> foo and bar both contain "c", bar and baz both contain "d". Without a
> namespace, the semantics from the first declared profile should be
> used in such cases and it is not possible to make use of the other.
> With a form of optional namespace, it should be possible to refer to
> those values in the following ways:
> The following unambiguosly refers "a" in foo in both cases:
> rel="a" OR rel="foo.a"
> Because "c" is defined in both foo and bar, these are equivalent
> because foo is defined first
> rel="c" OR rel="foo.c"
> With a namespace, "c" in bar, can also be unambiguosly referenced:
> Similarly, the follwing can also be unambiguously referenced:
> rel="b d baz.d e f"
Having namespaces only where conflicts occur strikes me as unwise - in
general the author is unlikely to know what the complete range of values
in a given spec is and it makes documents very fragile to addition of
data from new profiles and to addition of values to existing profiles.
It also makes view-source style learning hard because the namespace will
be included (or not) in an apparently random fashion. That's actually
one of the problems with XML namespaces - from a document like:
doing a simple view-source (without having read the Namespaces in XML
spec) doesn't make it obvious which namespace <element/> is in.
"But if science you say still sounds too deep,
Just do what Beaker does, just shrug and 'Meep!'"
-- Dr. Bunsen Honeydew & Beaker of Muppet Labs
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