Hallo ladies and gentlemen,

I spent a lot of time trying to find existing solution for very simple and in my opinion common task – validate XSL files that transform XML to XML. It's needed to be sure that all variants of transformed XML files will be valid (because there are a lot of variants of input data so there are a lot of variants of output data).

The idea has 2 steps.

The first step is to get the list of input XPaths from XSL (XPaths from input XML which are used in transformation process) and list of output XPaths from XSL (XPaths from output XML which are created in transformation process).

The second step is validation XPaths from input XML (that can be based on XSD of input XML) and validation XPaths from output XML (that can be based on XSD of output XML).

Thanks in advance,

Sergey.

The best way of doing this by far is to use Schema Validation. This is a new feature of XSLT 2.0 where you basically define a schema that the output must match.

This obviously could be done manually in a pipeline process, to validate the input and output against schemas.

I wouldn't recommend trying to process the XSLT file itself to 'guess' what the output might look like. Perhaps simply create a test suite of input XML to give you some form of test coverage might be a better way to go.

Sam

/- Sam Judson : Wrox Technical Editor -/

If you use schema-aware XSLT 2.0 then you have the potential for the XSLT processor to do this kind of checking. However, some points:

(a) the processor isn't obliged to do compile-time checking in the way you describe. Saxon does a certain amount, Altova as far as I can see only does run-time checking.

(b) Saxon won't give you errors unless you are careful to declare your types in suitable places. For example, if you write a template rule with match="schema-element(invoice)" and then use the path billTo-address/postcode then it will be able to tell you whether this is a legitimate path. However if you just use match="invoice", then all paths are legitimate, because your template rule can match invalid invoices as well as valid ones.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Thank you for your reply.

So as I understand there isn't the way to do the validation based on XSLT functionality.

So it will be Java solution.

Thank you,

Sergey