What is XML Schema Instance (XSI)?

[Zearin]

Hey,

I'm a longtime HTML/CSS junkie that has just become absolutely fascinated by the power of XML. What powerful things it can do!

Anywho, I was interested in writing an XML file which would contain the <model> for an XForm. I noticed the autocomplete wasn't kicking in, even though I gave it the namespace for XForms in an xmlns attribute. But no content assist--so I poked around and found oXygen's "Associate with a schema" option, and voila! It wrote the code necessary for content assist to kick in.

Instant XForms autocomplete. Thank you, oXygen.

However, one of the items in this generated code was the XSI namespace (http://www.w3.org/2001/XMLSchema-instance). I know what an XML Schema is (as in *.xsd files), but what is a Schema Instance? What is it used for?

Thanks one and all. This is some exiting stuff! [/code]

[george]

Hi Zearin,

The schema instance namespace (http://www.w3.org/2001/XMLSchema-instance) defines a few attributes that are used in instance documents with special meaning. The xsi:noNemaspaceSchemaLocation and xsi:schemaLocation attributes are used to associate XML Schemas with XML documents. The xsi:nil attribute is used in the XML instance documents to specify that an element defined as nillable in the XML Schema is nil. The xsi:type attribute is used to specify a specific type for an element in the instance document.
For more details see:
http://www.w3.org/TR/xmlschema-1/#Insta ... structions

Best Regards,
George