XML Schema same attributes names but different specific attribute sets of values? - xsd

Question

I wish to create a repeating same named element with two attributes for which the values of each are tied to each other. i.e.
<anElement id="R1" description="Some definition for R1"/>
<anElement id="R2" description="Some definition for R2"/>
Ideally I would define "groups" of id and description attributes together and reference one of the groups for each instance of anElement element.
<complexType name="RElements">
<choice>
<element name="anElement" type="R1Group"/>
<element name="anElement" type="R2Group"/>
</choice>
</complexType>
<complexType name="RElementsType">
<sequence>
<element ref="RElements" minOccurs="1" maxOccurs="unbounded"/>
</sequence>
</complexType>
But Choice doesn't allow multiples of the same element name. I see discussions about how to have multiple elements of the same name but none allow additional attributes let alone having attributes tied to each other. The only way that I can get close is by having a different named element based on the id. i.e.
<R1 id="R1" description="Some definition for R1"/>
<R2 id="R2" description="Some definition for R2"/>
Any suggestions?

Answer 1

You need to provide more information.
Basically to achieve the XML you have provided a simple schema like this would suffice.
<?xml version="1.0" encoding="utf-8" ?>
<!--Created with Liquid XML 2015 Developer Bundle Edition 13.0.3.5737 (http://www.liquid-technologies.com)-->
<xs:schema elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="RootElement">
<xs:complexType>
<xs:sequence>
<xs:element name="anElement" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="id" type="xs:string" />
<xs:attribute name="descritpion" type="xs:string" />
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>
However you mention that the attribute values id and description are linked, you may be able to constrain these, but you need to provide more info. Also I'm not sure why you are looking at choices? Its difficult to see what your attempting give you only provide snippets of the schema
To include the constraints described in later comments the following schema would allow this, but force a change in the XML structure
<AnElement id="E1"> Exterminator serial <ref id="E1"/> </AnElement>
<?xml version="1.0" encoding="utf-8" ?>
<!--Created with Liquid XML 2015 Developer Bundle Edition 13.0.0.5686 (http://www.liquid-technologies.com)-->
<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="RootElement">
<xs:complexType>
<xs:sequence minOccurs="0" maxOccurs="unbounded">
<xs:element name="AnElement">
<xs:complexType mixed="true">
<xs:sequence>
<xs:element name="ref" minOccurs="0">
<xs:complexType>
<xs:attribute name="id" type="xs:string" use="optional" />
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="id" type="xs:string" use="optional" />
</xs:complexType>
<xs:key name="IDVal">
<xs:selector xpath="." />
<xs:field xpath="#id" />
</xs:key>
<xs:keyref name="IdRef" refer="IDVal">
<xs:selector xpath="ref" />
<xs:field xpath="#id" />
</xs:keyref>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>