how to write an xml schema that allows part of the sequence not in place

Question

I need to write an XML schema that accept XMLs such as:

<?xml version="1.0" encoding="utf-8"?>
<Data>
  <NodeA>something</NodeA>
  <NodeB>something</NodeB>
  <NodeC>something</NodeC>
  <NodeD>something</NodeD>
</Data>

<?xml version="1.0" encoding="utf-8"?>
<Data>
  <NodeA>something</NodeA>
  <NodeC>something</NodeC>
  <NodeB>something</NodeB>
  <NodeD>something</NodeD>
</Data>

So in general, I want the elements in the list to be sequenced, except that a part of the list can appear in any order.

However I tried several appoaches for the xsd file and none of them works, e.g.

<xs:complexType name="Data">
  <xs:sequence>
    <xs:element name="NodeA"/>
    <xs:all xmlns:xs="">
      <xs:element name="NodeB"/>
      <xs:element name="NodeC"/>
    </xs:all>
    <xs:element name="NodeD"/>
  </xs:sequence>
</xs:complexType>

Putting NodeB and NodeC in a group doesn't work either.

I've googled those error messages but couldn't find anything useful...Why these xsds fails and how should I write it? Thanks!

find some other threads with different problems but caused by same issue. seems like it's a shortcoming of XML schema http://stackoverflow.com/questions/839079/middle-way-between-xsd-all-and-xsd-sequence http://stackoverflow.com/questions/2408095/xml-schema-putting-both-sequence-and-all-under-one-complextype-node http://stackoverflow.com/questions/7420512/how-to-mix-xsdsequence-with-xsdall — GoCurry, Apr 04 '12 at 17:44

Nick Ryan · Accepted Answer · 2012-04-05T09:12:39.357

1

How about this?

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="Root">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="NodeA"/>
                <xs:choice>
                    <xs:sequence>
                        <xs:element name="NodeB"/>
                        <xs:element name="NodeC"/>
                    </xs:sequence>
                    <xs:sequence>
                        <xs:element name="NodeC"/>
                        <xs:element name="NodeB"/>
                    </xs:sequence>
                </xs:choice>
                <xs:element name="NodeD"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
</xs:schema>

edited Apr 05 '12 at 09:12

answered Apr 04 '12 at 16:09

Nick Ryan

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Thanks! However I also tried this one before and the editor also throws an error... And a problem with this one is that the number of choices will increase in combination speed, so if I have more nodes I will be in trouble – GoCurry Apr 04 '12 at 17:08
xs:choice is the correct way. Try – Nick Ryan Apr 04 '12 at 17:57

how to write an xml schema that allows part of the sequence not in place

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