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Asked: 2026-05-11T09:35:06+00:00

Is there some sensible way to have elements with strongly-typed simple-types and also attributes?

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Is there some sensible way to have elements with strongly-typed simple-types and also attributes?

Okay, I have an XSD schema which has a million (er, hundred) elements that might look like this:

<xsd:element name='DocumentDescription' type='xsd:string' /> <xsd:element name='DocumentDateTime' type='xsd:dateTime' /> <xsd:element name='DocumentSize' type='xsd:int' />

That’s dandy. However, I really want all of these elements to also have some common attributes on them like, let’s say, ‘format’ and ‘isVisible’. i.e. have a schema like:

<DocumentDescription isVisible='true'>doc description</DocumentDescription> <DocumentDateTime format='dd/mm/yyyy' isVisible='true'>1/1/2008</DocumentDescription> <DocumentSize format='0.00 KB' isVisible='false'>5403</DocumentSize>

I could do it manually, and horribly, by adding all such attributes to the XSD when I generate it, something like this:

<xsd:element name='DocumentDescription' />   <xsd:complexType>     <xsd:simpleContent>       <xsd:extension base='xsd:string'>         <xsd:attribute name='format' type='xsd:string' />         <xsd:attribute name='isVisible' type='xsd:boolean' />       </xsd:extension>     </xsd:simpleContent>   </xsd:complexType> <xsd:element name='DocumentDateTime' />    ... etc

…but in an ideal world I’d rather define it as a complexType:

<xsd:complexType name='customType'>   <xsd:complexContent>     <xsd:extension base='???'>       <xsd:attribute name='format' type='xsd:string' />       <xsd:attribute name='isVisible' type='xsd:boolean' />

…which means I could just do:

<xsd:element name='DocumentDescription' type='customType' baseType='xsd:string' /> <xsd:element name='DocumentDateTime' type='customType' baseType='xsd:dateTime' /> <xsd:element name='DocumentSize' type='customType' baseType='xsd:int' />

The problem with my ‘ideal world’ code is that:

a) I’ve no valid <xsd:extension base-'???'>, since really I don’t care what I’m extending; I want to extend all types. Seems like the ‘xsd:anyType’ is appropriate, yet then the element becomes a weakly typed container does it not?

b) I can no longer specify the simple type on the <xsd:element>, since now the type is the complex ‘customType’ I defined. Hence the imaginary ‘baseType’ attribute I put there…

So can I add attributes to simple types in a non-clunky way? Or do I need to define a dozen complexTypes that are all identical except for the simple type that they extend?

Strongly-typed elements not only describe the data more sensibly, but when I use them for XML mapping in Excel (and this is the whole purpose behind these things), the strong-typing means that Excel sets the cell formatting correctly based on the type.

I’m probably looking at it all the wrong way! Any advice appreciated.

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1 Answer

  1. [quote]could do it manually, and horribly, by adding all such attributes to the XSD when I generate it, something like this:[/quote]

    I’m afraid this is your only ‘proper’, XSD-schema compatible way to do it.

    XSD can be convoluted to author at times – but it helps keeping things safe 🙂

    Marc

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