Franklin Tse wrote:
> Um...
>
> When an aggregator uses the empty "dir" attribute in an entry of an
> aggregated feed, it is actually asking another Atom processor to decide the
> text direction of that entry. Feed readers that read the aggregated feed may
> have difficulty in processing the entry, for example:
>
Yes.. but they're not asking those processors to do anything more than
what is currently already required.
> [snip]
> For the second entry, what should feed readers do? They should of course
> apply the default of the "dir" attribute, but what is the default value of
> the "dir" attribute? it is currently not specified in the draft. In addition,
> should they apply the direction guessing mechanism if they support it? The
> entry's base language is currently "he", inherited from atom:feed.
>
> However, in the draft:
>
> For compatibility with existing Atom documents that rely on direction
> guessing, user agents MAY perform direction guessing in documents
> that do not contain a "dir" attribute but they SHOULD NOT do so when
> a "dir" attribute is provided.
>
> When an Atom document contain a "dir" attribute, Atom processors should not
> apply any direction guessing mechanism. If that is the case, does an empty
> string mean that direction guessing can be used?
>
This is a spec bug. I had meant to change that to:
... user agents MAY perform direction guessing in documents where the
base direction is unspecified but they SHOULD NOT do so when a "dir"
attribute value of "ltr" or "rtl" is provided.
This will allow user agents to apply whatever heuristics it wants to
determine the base directionality where the dir is unspecified.
I will fix this in another iteration.
> [snip]
> PS: In the example above, if the second entry comes from a source feed that
> does not contain any "xml:lang" attribute or "dir", aggregators have to
> generate xml:lang=""[1][2] and dir="" together. (<entry xml:lang=""
> dir=""></entry>). It is very problematic if only dir="" is generated.
>
Yep. Not sure if this needs to be discussed in this doc, however.
- James
