Leigh Dodds has announced a beta release of a Schematron validator for RSS, the lightweight headline syndication format.

The validator, which can be downloaded from Dodds' site, is an XML document to be run through Schematron. Schematron generates an XSLT stylesheet for performing the actual validation of RSS documents.

Although the current release checks the Netscape field length limitations, Dodds says that they may not be common usage:

For example, restricting URL lengths seems unnecessary. However there is some obvious value, if an RSS feed is going to be stored in a database.

The date-time formats are not checked by this release:

Common usage suggests these conform to that specified in RFC822. Potentially a Java extension function could be used to perform this more efficiently than in XSLT. Its unclear how this would be achieved in Schematron.

Dodds indicates that some work is to be done on error messages and that the validator will be extended to cover modular RSS as discussed on the syndication mailing list:

My plans are to collate feedback, undertake some additional testing, and tidy up the error messages before releasing this as version 1.0 (they're a bit rough at the moment).

I'm also planning to update the validator so that it is capable of validating the Modular RSS format discussed on this list recently.

The validator is distributed under a liberal open source licence:

The contents are dedicated to the public domain by the author, Leigh Dodds <leigh@xmlhack.com>, except that Leigh Dodds retains the moral right to be known as the author.

Related story:

• Will RSS fork?

(Leigh Dodds is a contributing editor to xmlhack).