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Simple List Questions

I’m looking into adding FeedValidator support for Microsoft’s Simple List Extensions Specification, and have a few questions:

Answers to these questions, as well as identification of other areas of potential confusion, would be appreciated.

Should there be errors or warnings issued for any of these conditions?

Update: Added question on embedded HTML.

Update: There is now a proposed revision and a wiki page.

Update: Added question on multiple <cf:listinfo> elements.


Just passing time with my everyone-has-one while waiting for official word:

Did you know that your asterisks-to-ul code doesn’t tolerate having a comment end with a list item? I tried to stop there, but it wouldn’t let me.

Posted by Phil Ringnalda at

Did you know that your asterisks-to-ul code doesn’t tolerate having a comment end with a list item? I tried to stop there, but it wouldn’t let me.

Posted by Sam Ruby at

Sam Ruby: Simple List Questions

“I’m looking into adding FeedValidator support for Microsoft’s Simple List Extensions Specification, and have a few questions”...

Excerpt from del.icio.us at

Repeating an element in cf:sort or cf:group shouldn’t mean anything - aren’t they both just booleans

What does the following mean?

<cf:listinfo>
  <cf:sort>
    <my:field data-type="date">my field as date</my:field>
    <my:field date-type="text">my field as text</my:field>
  </cf:sort>
</cf:listinfo>

If an item is in both, then the top of the column for that element’s content ought to have a “sort-by” widget, and each item’s value ought to have a “only-these” widget by it.

I don’t see widgets mentioned in the spec, but as an analogy, mysql doesn’t particularly care for statements of the form:

select * from item order by pubDate group by pubDate;

Lacking the element for a cf:sort ought to make it null

Either that, or it was a typo, as in:

<cf:sort>
  <pubdate data-type="date">publication date</pubdate>
</cf:sort>
Posted by Sam Ruby at

I wish I could remember who sat on the other end of Socrates' log.

Ignoring the typo in the attribute name, repeating an element for sorting with two different data-types means that the publisher thinks it would be useful to allow sorting of the list by that element in either order. Erm. Full RFC 2822 dates, where a date sort puts January 1 first, and a text sort puts weekdays together? Had they asked us before they announced, I would have +1’ed your request that an element only be allowed to have one data-type, since that’s the closest I can come to a useful example of an element having two, so I doubt that implementors will actually provide for multi-type sorting. Which means that the sorting algo for that example will be unpredictable, with some implementations saving the last data-type they saw, and others discarding any later data-types once they’ve seen one, which makes it a validator warning if MS won’t give us spec text, and an error if they will.

Widgets I inferred from the typoed

The consumer of the feed should then use the cf:sort and cf:group elements to show a user interface that allows the user to sort on the item properties listed under cf:group, and to filter/group by the items listed under cf:group.

Since, most curiously, there’s no spec text to say which of multiple sort elements is primary, and that the primary (or for that matter any) sort should be used for initial display, I’m assuming they mean for implementors to start with whatever order pleases them, and let the user tell the program if she wants to sort by a cf:sort element, which I suspect will usually show up like the column heads in Windows Explorer’s “details” view. How that gets shoehorned into a typical aggregator is left as an exercise for the poor implementor.

While I still think having an item that doesn’t contain the sort key isn’t an error, I would hope that if someone says that pubdate is a sort key then no items would contain it, which is certainly very good cause for warning.

Markup in the human readable name? How would you be able to tell whether or not it was (escaped) markup?, he asked in a wide-eyed and innocent way.

Posted by Phil Ringnalda at

1. cf:listinfo without a cf:treatAs means that you should sort and group the feed using those fields but you shouldn’t apply list semantics to deleting items and the like.

2. Ignore latter occurences of the same element in cf:group and cf:sort. 

3. It means you can both sort and group by the field. E.g. the category element.

4. That’s up to the client to decide. This is no different from what clients that can sort by category need to do when some items don’t have a category.

5. The readable name for the group can’t contain HTML.

PS: I’ll talk to Sean about adding these to the spec.

Posted by Dare Obasanjo at

1. cf:listinfo without a cf:treatAs means that you should sort and group the feed using those fields but you shouldn’t apply list semantics to deleting items and the like.

OK, so no error or warning.

2. Ignore latter occurences of the same element in cf:group and cf:sort.

Sounds like a warning is merited here.

3. It means you can both sort and group by the field. E.g. the category element.

OK, so no error or warning.

4. That’s up to the client to decide. This is no different from what clients that can sort by category need to do when some items don’t have a category.

I’ll probably do something like what Phil suggested, i.e., produce a warning if none of the items match, unless the field is a well known one (like category).

5. The readable name for the group can’t contain HTML.

Not 100% foolproof, but I’ll probably produce a warning if I see some sequence like &lt;/ in the readable name then.

PS: I’ll talk to Sean about adding these to the spec.

Excellent!

Posted by Sam Ruby at

More reactions on Microsoft's RSS announcements

Here’s a bunch more feedback about the RSS announcements made yesterday: Phil Ringalda: MS Embraces RSS. “Simple List Extensions: ouch. That crunching sound you heard was me getting bit on the butt, hard.” Dave Winer: Quick postscript on Microsoft...

Excerpt from Scobleizer: Microsoft Geek Blogger at

Update: There is now a proposed revision and a wiki page.

I see we’re back to relying on blog posts and tea leaves to divine the intentions of “spec” writers.

Posted by Mark at

Now, Mark. In RSS today, we have more than our share of the nattering nabobs of negativism. When will the impudent corps of effete snobs stop their pusillanimous pussyfooting? Why should RSS be held hostage by hopeless, hysterical hypochondriacs of history?

Posted by Robert Sayre at

Expect better

Data above the level of a single site is immensely valuable to people. If you’re in the software business and have you’ll know by by now that data is the new platform. Which is why David Berlind’s take on Microsoft’s RSS is disappointing ... [more]

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at

Links for 2005-06-26 [del.icio.us]

Mark Evans :: Frustrations With Blog Search (and Technorati) Daily Source Code #200 Micro Persuasion: The Day RSS Turned Pro Subscribe to Your Own Feedburner Statistics How To Use Mime-Types To Get Your Aggregator To Subscribe To An Atom ... As I...

Excerpt from iBLOGthere4iM at

Links for 2005-06-26 [del.icio.us]

Mark Evans :: Frustrations With Blog Search (and Technorati) Micro Persuasion: The Day RSS Turned Pro Subscribe to Your Own Feedburner Statistics How To Use Mime-Types To Get Your Aggregator To Subscribe To An Atom ... Bill de h�ra: Expect...

Excerpt from The RSS Blog at

More reactions on Microsoft’s RSS announcements. Here’s a bunch more feedback about the RSS announcements made yesterday: Phil Ringalda: MS Embraces RSS. "Simple List Extensions: ouch. That crunching sound you heard was me getting bit on the butt,...

Excerpt from The Wilk's Blog at

Reactions to MS RSS announcement (some repetition here).

Reactions to MS RSS announcement (some repetition here). More reactions on Microsoft’s RSS announcements. Here’s a bunch more feedback about the RSS announcements made yesterday: Phil Ringalda: MS Embraces RSS. "Simple List Extensions: ouch. That...

Excerpt from Home-Based Entrepreneur at

Countdown

Links and a countdown....

Excerpt from Anne’s Weblog about Markup & Style at

Why Standards matter [1]

I’m looking into adding FeedValidator support for Microsoft’s Simple List Extensions Specification, and have a few questions. – Sam Ruby So now developers of RSS readers that want to consume podcasts have to know how to consume the RSS 2.0 element,...

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Microsoft moves on the RSS Front

Dare Obasanjo: Gnomedex 5.0 Trip Report: Dean Hachamovitch on Longhorn, IE 7 and RSS Phil Ringnalda: MS embraces RSS Sam Ruby: Simple List Questions...

Excerpt from From the Belly of the Beasts at

This is Sharing?

Microsoft introduced the term  shared source, and now seems to be extending their unique idea of “sharing” to syndication. The first attribute that the the Simple Sharing Extensions for RSS and OPML is to “treat the item list as an or... [more]

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at

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