Re: [XSLT 2] rescue
> Unfortunately there is no try-catch in XPath 2 or XSLT 2.
This indeed is unfortunate. Luckily those specs are still drafts, so I hope that the final versions will satisfy this important requirement (which you seem to share).
> We debated putting one in, but people felt it was a bridge too far. > People were particularly concerned about defining exactly what state > the system was in if an error was trapped and ignored,
I don't want to ignore it, but instead I must be able to deal with it.
If my XSLT application, running without supervision (eg on the server), gets fed a document which references a non-existent file, then my application must be able to deal with that; It is unacceptable to abort the whole transformation. Since I'm not aware of any facilities to test for the existence of files (validity of paths/URIs), I need a way to recover from the currently unfortunately fatal error raised after a failed unparsed-text().
> for example, should > it effectively be required to do a "rollback" of the result tree.
AFAICS, this question does not arise for the type of scenario I describe. Since it probably is a very common use case, and since there probably are many more use cases where error recovery facilities are needed and the rollback question does not arise, I suggest to add those facilities.
The rollback issue can be dealt with in cases where it's an issue; if there is no solution, then those cases can not have recovery facilities.
XSLT 2 / XPath 2 should offer error recovery facilites, for cases where it makes sense and is feasible to specify. They are crucial, and are found in many if not most programming languages.
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
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