xsd - XML Schema: Element that can contain elements or text?

Question

How would I define an element that can either contain plain text or contain elements? Say I wanted to somehow allow for both of these cases:

<xs:element name="field">
    <xs:complexType>
        <xs:sequence>
            <xs:element ref="subfield" minOccurs="0" maxOccurs="unbounded" />
        </xs:sequence>
        <xs:attribute name="name" type="xs:string" />
    </xs:complexType>
</xs:element>

<xs:element name="field" type="xs:string" />

... so that both these elements would be valid:

<field name="test_field_0">
    <subfield>Some text.</subfield>
</field>

<field name="test_field_1">Some more text.</field>

Answer 1

I did some research on this a while ago and the only solution I found was to used the mixed attribute:

<xs:element name="field">
    <xs:complexType mixed="true">
        <xs:sequence>
                <xs:element ref="subfield" minOccurs="0" maxOccurs="unbounded" />
        </xs:sequence>
        <xs:attribute name="name" type="xs:string" />
    </xs:complexType>
</xs:element>

This sadly also allows

<field name="test_field_0">
    Some text I'm sure you don't want.
    <subfield>Some text.</subfield>
    More text you don't want.
</field>

Hopefully someone will give a better answer.