XMS schema and Generalisation of ComplexType

[noon]

Does the concept of Generalization (present in object language) exist in XML Schema ?

Here is a simple XML example of what i'd like to write :

<FruitBag>
<Apple color=&quot;red&quot; radius=&quot;2&quot;/>
<Orange color=&quot;orange&quot; radius=&quot;2&quot;/>
<Banana color=&quot;yellow&quot; heigth=&quot;5&quot;/>
</FuitBag>

And here is the kind of declaration i'd like to have :

a fruit :

<xs:complexType name=&quot;FruitType&quot;>
<xs:attribute name=&quot;color&quot; type=&quot;xs:string&quot; />
</xs:complexType>

an apple :

<xs:complexType name=&quot;AppleType&quot;>
<xs:complexContent>
<xs:extension base=&quot;FruitType&quot;>
<xs:attribute name=&quot;radius&quot; type=&quot;xs:string&quot;/>
</xs:extension>
</xs:complexContent>
</xs:complexType>

a banana :

<xs:complexType name=&quot;BananaType&quot;>
<xs:complexContent>
<xs:extension base=&quot;FruitType&quot;>
<xs:attribute name=&quot;heigth&quot; type=&quot;xs:string&quot;/>
</xs:extension>
</xs:complexContent>
</xs:complexType>


and for the FuitBag, i'd like to define it like a container of FruitType. It can contain Apple, and/or Banana, because Apple and Banana are FruitType.

But if i define it like this :

<xs:complexType name=&quot;FruitBag&quot;>
<xs:sequence>
<xs:element name=&quot;Fruit&quot; type=&quot;FruitType maxOccurs=&quot;unbounded&quot;/>
</xs:sequence>
</xs:complexType>


A valid XML would be :

<FruitBag>
<Fruit color=&quot;red&quot; />
<Fruit color=&quot;orange&quot; />
<Fruit color=&quot;yellow&quot; />
</FuitBag>

And that's not what I want.
I don't want to define FruitBag like a container of Apple Banana, etc,
because I can have a lot of different fruits type, and if I define another kind of Fruit, i would have to add it to the declaration of my FruitBag.

So does this concept exist in XML schema ?
Or is there any way to do something like this ?

Thanks for the answers.
(Sorry if the question have allready been asked)

 

[Nosferatu]

No, there is no such thing in xml schemas (at least, none I know about; I would welcome somebody who knows this way or the other for sure).

But, instead generalizing, I would suggest using aggregation, so have a fruit complext type which is a collection of all other fruits, selected by a choice statement...

That is, keep your fruit bag as it is, but have the fruit type as:

<xsd:element &quot;Fruits&quot;>
     <xsd:choice>
       <xsd:element name=&quot;Banana&quot; type=&quot;BananaType&quot;/>       
       <xsd:element name=&quot;Apple&quot; type=&quot;AppleType&quot;/>
etc...

I don't know if this would suit you...
HTH

You will have to add all the new fruits to your Fruits datatype. [red]Nosferatu[/red]
We are what we eat...
There's no such thing as free meal...
once stated: methane@personal.ro

 

[noon]

It doesn't really suit to hat i want to do, but its an idea.

Thanks for your answer.