Reading and Iterating through an XSD Schema?

[Cy Huckaba]

I have been looking around for a sample on how to read an XSD schema and iterate
through the elements to display them.

I am working in VB.Net and I have looked at all of the docs on msdn and can find
plenty of samples on how to read it in and then write it write back out...with
no manipulation or analysis before writing. I load the XMLSchema object but
can't get into the right collection of objects to get back any valid items.

I was just tyring to do a load a schema that is not terrible complex and list
the names of each of the Elements in a textbox control on a form...I will go for
attributes for each element after that.

Anyone have an article that I can read...any simple samples.

Thanks in advance,

Cy Huckaba
Austin, TX

[MSFT]

Hi Austin,

From XMLSchema object's property, we can only get the inforamtion about
namespace and SourceUri. However, XSD file is also a text file in XML
format. I think you can read it as a common XML file with XMLTextReader and
list all elements nodes in the textbox.

Luke

"Microsoft Security Announcement: Have you installed the patch for
Microsoft Security Bulletin MS03-026?? If not Microsoft strongly advises
you to review the information at the following link regarding Microsoft
Security Bulletin MS03-026
http://www.microsoft.com/security/se...s/ms03-026.asp and/or to
visit Windows Update at http://windowsupdate.microsoft.com to install the
patch. Running the SCAN program from the Windows Update site will help to
insure you are current with all security patches, not just MS03-026."

[Daniel Cazzulino]

You have full access to what's called the SOM (Schema Object Model). That
includes knowing if an element is a simple or complex type, its particles
(i.e. child elements), etc.
The Items/Elements/Attributes will only give you those items that are
defined globally, NOT those that are local elements, which is quite common
and, IMO, a better design practice if the elements/types are not going to be
reused anywhere else.
The easiest way is to get first the top-level elements through the .Elements
property. Here's how to iterate:

foreach (DictionaryEntr y entry in schema.Elements )
{
if (entry.Value is XmlSchemaElemen t)
{
//We have an element
}
}

Next, you can query its type (to see if they have a complexType definition)
and keep going to list the children. This is done as follows (requires a
recursive function to be effective, actually, but you get the idea):

XmlSchemaElemen t rootelement = (XmlSchemaEleme nt) entry.Value;
if (rootelement.Sc hemaType is XmlSchemaComple xType)
{
XmlSchemaComple xType roottype =
(XmlSchemaCompl exType)rootelem ent.SchemaType;

// Check for a sequence child element (particle content model). May be a
choice too, for example.
if (roottype.Parti cle is XmlSchemaSequen ce)
{
XmlSchemaSequen ce rootseq = (XmlSchemaSeque nce) roottype.Partic le;
foreach (Dictionary innerentry in rootseq.Items)
{
if (entry.Value is XmlSchemaElemen t)
{
//Recurse forever ;)
}
}
}
}

--
.../dcazz
Daniel Cazzulino
DEVerest - Lagash
Tel [phone]
www.deverest.com.ar
www.lagash.com
dotnetopensrc.s ourceforge.net

Coauthor of:
Beginning C# Web Applications with Visual Studio .NET
Beginning Web Programming using VB.NET and Visual Studio .NET
Professional ASP.NET Server Controls: Building Custom Controls with C#
ASP.NET Components Toolkit

"He who is good for making excuses, is seldom good for anything else."

"Cy Huckaba" <ru******@t-3.com> wrote in message
news:e0******** ******@tk2msftn gp13.phx.gbl...

OK, at least I'm not going crazy.

If I put an xpath navigator on it Can I cast the nodes I want into XMLSchema Elements so I can have access to datatypes, etc?

I'll give it a shot...thanks for the reply.

Cy

"MSFT" <lu******@onlin e.microsoft.com > wrote in message
news:cE******** ******@cpmsftng xa06.phx.gbl...

Hi Austin,

From XMLSchema object's property, we can only get the inforamtion about
namespace and SourceUri. However, XSD file is also a text file in XML
format. I think you can read it as a common XML file with XMLTextReader and list all elements nodes in the textbox.

Luke

"Microsoft Security Announcement: Have you installed the patch for
Microsoft Security Bulletin MS03-026?? If not Microsoft strongly advises
you to review the information at the following link regarding Microsoft
Security Bulletin MS03-026
http://www.microsoft.com/security/se...s/ms03-026.asp and/or to visit Windows Update at http://windowsupdate.microsoft.com to install the patch. Running the SCAN program from the Windows Update site will help to insure you are current with all security patches, not just MS03-026."

[MSFT]

Yes, you can do this. You also can consider SOM as Daniel suggested. (Thank
for Daniel's suggestion)

Luke

(This posting is provided "AS IS", with no warranties, and confers no
rights.)