Graham wrote:
On 9 May 2005, at 6:48 pm, Bill de h�ra wrote:
I think this exercise is *critical* for any piece of markup that is going to move from mandatory to optional. Either way, we should pin down spec language around the optionality of alternate feed links, or consciously decide we're not going to pin it down.
So you wouldn't support a proposal that removed a required element without explaining what it's absence meant (eg PaceAtomSummary), because you'd prefer one that leaves it much less ambiguous (eg PaceTextShouldBeProvided, which strongly encourages publishers to only omit atom:summary when none exists)?
I'm not surprised at this line of thought since there is also another dicussion going on around optional summaries. You're jumping the gun though and/or possibly trying to pin me into some kind of non-existent corner - fair enough. What I would like is that we at least discuss the consequences of making non-optional things optional on the data beynd some people can't supply meaningful alternates - I happen to be one of those people btw, if I haven't said it already. And some consistency of debate around loosening constraints is good I think. Finally, there is an important distinction between the two cases (optional alternates and optional summaries).
The difference is in what can be concluded from the data, ie it's a 3-valued logic problem. Does the absence mean there's no alternate? Does it mean don't unknown? Do we need to care?
Answer Tim's question: "What observable difference in the behavior of software would be affected by this difference?"
I can have nullable columns in my database depending on what we decide to do here. That affects the behaviour of my SQL queries and depending.
I can can constrain the search for alternates in a nypertext graph if I know the author is saying there is no alternate. That affects (massively in some cases) the behaviour of an RDF query backend among other things. similar arguments can be made for search systems that are working off raw indexes.
I can send the message "there is no alternate for this feed" or "no alternate was provided for this feed" or "no alternate was found for this feed" depending on what we decide to do here.
Is that enough? Do you see that the point of this pace is to shine some light on what we're doing here? Btw, I'm 0 on PaceNoAlternateForFeed - like I said, I have feeds that have no real alternates.
cheers Bill
