I use MVVM pattern in my project. I describe a view via XML. But I need to split it into several XML files because one XML file will be too large.

When my parser reads XML it find "Source" attribute first. If it exist the parser loads other XML document and reads element from this document. Else, if "Source" attribute does not exist parser reads other attributes.

Example with Source attribute:

```
<RibbonDefaultPageCategory>
  <RibbonPage
    Source="DefaultPageCategory/RibbonPage.xml"/>
</RibbonDefaultPageCategory> 

```

Example without Source attribute:

```
<RibbonDefaultPageCategory>
  <RibbonPage
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="_Schema.xsd"
    RibbonPageTitle="RibbonPageTitle">
     ...
   </RibbonPage>

```

Is it possible define this behavior in XML schema? Maybe it is possible use XML Element instead of attribute?

Like this

```
<ExternalElement
    ElementName="RibbonPage"
    Path="DefaultPageCategory/RibbonPage.xml"/> 

```