XSD vs XSI

[ranch99ranch99]

What's the difference between XSD and XSI?

 

[Bjoern Hoehrmann]

* (e-mail address removed) wrote in comp.text.xml:

What's the difference between XSD and XSI?

Presumably you want to know that these are different initialisms, one is
typically expanded to "XML Schema Document" or "XML Schema Datatypes" or
similar, while the other is typically expanded to "XML Schema Instance".
When used as namespace prefixes, they usually expand to different name-
space names.

 

[Joe Kesselman]

typically expanded to "XML Schema Document" or "XML Schema Datatypes" or

.... or XML Schema Definition. Which of these meanings applies depends on
the context in which the term is used.

When used as namespace prefixes, they usually expand to different name-
space names.

xsd: usually maps to "http://www.w3.org/2001/XMLSchema", which is the
namespace for schemas themselves. You'd use this namespace to define the
datatypes and normal structure of your document.

xsi: usually maps to "http://www.w3.org/2001/XMLSchema-instance", which
is the namespace for schema-related information that appears in instance
documents. You'd use this namespace to do things like say which schema
document describes this document, or to state that an element is a
particular sub-type of the type the schema requires it to be.



If that doesn't help you, ask a more specific question. Or perhaps just read
http://www.w3.org/TR/2004/REC-xmlschema-0-20041028/
or another introduction to XML Schema and its uses. (Herewith, my
standard plug for the many tutorials and articles at http://www.ibm.com/xml)

 

[ranch99ranch99]

Thanks.

The XML file that I encounter has a line
<manifest xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3org/2001/XMLSchema-instance">

I don't quite understand what's the meaning of this line. If you can
provide some examples , that will be more helpful.

 

[Joseph Kesselman]

<manifest xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3org/2001/XMLSchema-instance">

I don't quite understand what's the meaning of this line. If you can
provide some examples , that will be more helpful.

It has an element called manifest -- whatever that is -- which declares
the xsd and xsi namespaces. See the links I pointed you to for
information about what those namespaces are used for. If you don't
understand XML namespaces, see a good XML tutorial.