make sure that in the 'META-INF/services' folder from within the .jar
Hi George and Adrian, Re: the appropriate factory class is specified (use a ZIP archive tool like 7-zip to check). Yes, you're absolutely right about that requirement, and thanks very much for the advice, but I don't think that's it. That was one of the first things that occurred to me. The following file in my (non-working) datatype .jar: META-INF/services/org.relaxng.datatype.DatatypeLibraryFactory has the same content: nu.validator.datatype.Html5DatatypeLibraryFactory as the same file in the .jar that does work. Byte-identical, right down to the x'0A' end-of-line character. And, as I mentioned, they both work in jEdit, which also uses Jing. If you swear that Oxygen doesn't have a persistent parser cache lurking that might be the culprit, then I guess I'll have to do some more digging. I want to see an error that I can act on. I think being able to edit XHTML5 in Oxygen - and other validating XML editors that are capable of it - using the "living" v.Nu schemas is a worthy goal. I'm going to persevere. And, yes, I use 7-Zip to perform surgery on .jar files. Nice tool. But it changes the "order" of files in a .jar as reported by the tf option of the jar utility. I got paranoid about that and, in one permutation of my testing, I used the jar utility to re-create the datatype .jar with the META-INF directory and its files deliberately right at the top of the tf listing. Nope. Made no difference. If/when I get this working (well, it already is; I mean: working with my own "reproducible" .jar :-) ), I might get back to you about validating XHTML5 that contains custom data-* attributes, using the combination of the v.Nu schemas and your tweaked parser code mentioned in: https://www.oxygenxml.com/forum/topic7698.html I sincerely don't mean any offence, but I am curious why Oxygen doesn't offer out-of-the-box support for XHTML5 validation using the "living" XHTML5 schemas from v.Nu. When I started looking into XHTML5 validation, it became clear to me that the v.Nu schemas were the best choice. For some background on my investigation, see: https://github.com/validator/validator/issues/251 Even if you disagree with Mike(tm) Smith's "canonical" comment (do you?), anyone who goes looking at the HTML5 spec on either the WHATWG or W3C website for information on validating XHTML5 will end up at the Nu Html (sic) Checker (Validator.nu; v.Nu). It makes sense to me for editors that can support the same schemas to do so. But Oxygen is not alone in this. I've started doing the rounds of the free validating XML editors that I'm aware of, and the commercial ones my employer has paid for on my behalf, and none, so far, have pointed out-of-the-box to the "live" v.Nu schemas on GitHub. Having looked into it, I can see there are some reasons for that, that I'm working on, as described at: https://github.com/unsoup/validator It's good to have a hobby, right? ;-) Thanks again for your advice so far. Cheers, Graham Fundi Software Pty Ltd 2016 ABN 89 009 120 290 This message has been scanned for malware by Websense. www.websense.com