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Sam Ruby has introduced OPML validation into his Feed Validator. As usually, he's created a set of contrived samples to show the difference between the three validators; Dave's OPML Validator, my Really Simple Validator and the Feed Validator. The varying results concern me.

The Really Simple Validator validates against the spec, as written. The other two validators validate part against the spec, part against Dave's guidelines and part against something unknown to me. The concern? The guidelines seem to introduce new constraints to the grammar and validating against an unknown seems wrong. Is this OPML 1.1 or 1.2 and where's the spec?

http://www.intertwingly.net/blog/2005/10/31/OPML-validators

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Mon, 31 Oct 2005 17:03:59 GMT

"As usually"? Give me a break. Do your homework. I contrived no samples. Look closer at where each is hosted if you don't believe me.

Despite all this: I strongly agree with you on one point: where's the spec?

- Sam Ruby

P.S. I made it clear that I wanted to point to a mainted validator. Despite this prereq not being met, I pointed anyway. Over six weeks ago.

Mon, 31 Oct 2005 18:04:24 GMT

Sam, sorry, my mistake, I should have said "contrived set of samples", not "set of contrived samples". My bad. I'm not certain where my validator is not being maintained. And thanks for the link.

Randy

Mon, 31 Oct 2005 18:44:14 GMT

In case you were wondering about the selection criteria, take a look at the test cases. They consist exclusively of the initial set of tests for the OPML validator, augmented by the additional test case the Dave Winer added, and the two additional tests that Nick Bradbury proposed (and Dave appears to be considering).

For the summary on my weblog, I simply included the ones where we differ. All of the differences — no selection bias here. For summary purposes, it isn't all that interesting to point out that we all report on missing body elements. What is, however, worth noting is that we differ (for the moment — Dave is apparently still considering this issue) on whether or not it is valid for outline elements to exist outside the body.

Nor does it surprise me that the OPML spec contains examples that Dave's validator finds to be invalid. Nor does it surprise me that the FeedValidator support I hacked together last night agrees - I said that I started from the test cases, and not from the spec. - Sam Ruby

Tue, 01 Nov 2005 00:49:46 GMT

This is a great conversation. Feed validation is important. Any idea how Feedmesh works with OPML? Or is it a concern at all?

Wed, 02 Nov 2005 21:55:17 GMT

OPML Feed Validation Discussions Abound on RSS Applied:

Sam Ruby’s FeedValidator now includes OPML (Outline Processor Markup Language) validation. The controversy seems to surround the spec:

The Really Simple Validator validates against the spec, as written. The other two validators validate part against the spec, part against Dave’s guidelines and part against something unknown to me. The concern? The guidelines seem to introduce new constraints to the grammar and validating against an unknown seems wrong. Is this OPML 1.1 or 1.2 and where’s the spec?

Be sure to read the comments. Sam Ruby chimes in to explain some of the concerns.

Randy

Wed, 02 Nov 2005 21:55:52 GMT

I don't believe Feedmesh attempts to address OPML.

Randy

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