Validate XML element against schema

Question

I need to validate a small fragment of an xml file against a schema. Essentially, I'd like to ask the question "Does element X in XML document Y conform to its type as defined in schema Z?" and if not get a message describing why. This has to account for restrictions placed on those types as well (eg maxLength, minInclusive).

Is this possible?

Answer 1

I don't know about doing this from C#, but it's easily done in XQuery or XSLT 2.0. In XSLT 2.0 it's:

<xsl:copy-of select="doc('doc.xml')//selected/element" validation="strict"/>

and in XQuery it's

validate strict {doc('doc.xml')//selected/element}

All you need is a schema-aware XQuery or XSLT 2.0 processor that runs in your chosen environment.

Answer 2

It turns out this was much easier than I expected. The solution was to create a new schema that contains as its root the one element I want to verify. Once this schema is added to the schemaset, you can simply validate the fragment as you would any complete document.

Answer 3

A microsoft knowledge article that exactly describes validating Xml fragments. This could be useful. http://support.microsoft.com/kb/318504