How to insert a xml element from another namespace as a child and still be a valid xml?

Question

I have the following xml file

<Layout xmlns="http://tempuri.org/Layout/"&gt;
  <Numeric Id="temperature" Caption="Temperature">
    <validation:IsValidWhen xmlns:validation="http://tempuri.org/Validation/"&gt;

    </validation:IsValidWhen>
  </Numeric>
</Layout>

The http://tempuri.org/Layout/ XSD does not have a reference to http://tempuri.org/Validation/ and I cannot change it.

I am getting the error

The element 'Numeric' in namespace 'http://tempuri.org/Layout/' has invalid child element 'IsValidWhen' in namespace 'http://tempuri.org/Validation/'. List of possible elements expected: 'ContextMenu, OnChanged, OnLeave' in namespace 'http://tempuri.org/Layout/'

How can I make this XML be valid when the parent element is from a schema that is not aware of my validation schema?

Answer 1

If you do not control the http://tempuri.org/Layout/ schema, then there may not be anything you can do to make this "valid." However, it's still perfectly reasonable and well-formed XML that can be used by any party that knows what to expect. If the other parties you're interacting with understand the format, there really isn't any problem.

Answer 2

Perhaps you can use XML catalogs to instruct your tools (or code, which has strict validation) where to locate multiple unrelated schemas.