XSD : Check order of child elements based on attribute

Question

I am trying to check the order of the child elements in an xml,

My xml is

<main>
<col name="name1">test1</col>
<col name="name2">test2</col>
<col name="name3">test3</col>
<col name="name4">test4</col>
<col name="num1">true</col>
</main>

and I need to verify if the child elements are getting displayed in the correct order. The child elements in my file all have the same name but different attributes.

<xs:element minOccurs="0" maxOccurs="unbounded" name="col">
<xs:complexType>
<xs:simpleContent>
<xs:extension base="xs:string">
<xs:attribute name="name" type ="OrderCheck" use="required" />
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>

I would ideally like to do

<xs:complexType name="OrderCheck">
    <xs:sequence>
    <xs:element name="name1" type="xs:string"/>
    <xs:element name="name2" type="xs:string"/>
    <xs:element name="name3" type="xs:string"/>
    <xs:element name="name4" type="xs:string"/>
    <xs:element name="num1" type="xs:boolean"/>
    </xs:sequence>  
    </xs:complexType>

For me to be able to use xs:sequence I need to define a xs:complexType but I am not able to define a complexType under the "attribute" type, I can define only a simple type.But I cannot use xs:sequence under simpleType. How can I fix this?

Michael Kay Michael Kay · Accepted Answer · 2013-01-09T10:52:33

If you can use XSD 1.1 (implemented in Xerces beta and in Saxon-EE) then you can do this with assertions.

Another technique that can sometimes be useful in cases like this is to implement your validation process as a two-stage pipeline, consisting of a transformation followed by a validation step. The transformation would typically convert

<col name="name1">test1</col>

to

<name1>test1</name1>

and then you have a structure that is readily amenable to XSD 1.0 validation.

XSD : Check order of child elements based on attribute

2 Answers