Question

Is there a way to enforce the standard isA relationship in an xmlSchema?

so something like

<complextype name="item">    
  #can be one of    
  <element type="desktop computer"/>    
  <element type="laptop"/>    
  <element type="smartphone"/>    
</complextype>

The whole idea being that an element of type=”desktop computer” can have entirely different members compared to that of say type=”smartphone”

It’s basically trying for something similar to the grammar :-

itemlist = item | item . itemlist    
item = common_desc . (desktop_computer | laptop | smartphone)    
desktop_computer = monitor_specs . cabinet_dimensions . blah    
smartphone = carrier . 3g_enabled . blah_blah

and so on…

I know that this sounds like a fairly contrived example and you may argue that I would need to define a new type for each item_type… but let’s assume that this is a very limited set of types…

Or you could take the example from the other question on isA relationships about feeds (Recovering types through an Isa relationship )

Answer 1

You can use xs:choice like this :-

<complexType name="item">
    <choice>
        <element name="dc" type="desktop_computer"/>
        <element name="lp" type="laptop" />
    </choice>
</complexType>