Add attributes to a simpletype or restriction to a complextype in Xml Schema

I'd like to propose my example with more detailed explanation what actually require for mixing up inherited type with restrictions while adding attribute.

this is the place you define your inherited type (in my case it's xs:string based one with field lenght 1024 restriction applied). you can't have this as a standard type for your field as you are going to add an "attribute" to your field too.

  <xs:simpleType name="string1024Type">
    <xs:restriction base="xs:string">
      <xs:maxLength value="1024"/>
    </xs:restriction>
  </xs:simpleType>

this is the place where your element is defined based on your private type (in my case it's "string1024Type") and necessary attribute appended:

<xs:element maxOccurs="unbounded" name="event">
  <xs:complexType>
    <xs:simpleContent>
      <xs:extension base="string1024Type">
        <xs:attribute default="list" name="node" type="xs:string"/>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:element>

both blocks could be in completely separate places of your schema. the important point is only following once again - you can't mix inheritance and attributing in the same element definition.

To add attributes you have to derive by extension, to add facets you have to derive by restriction. Therefore this has to be done in two steps for the element's child content. The attribute can be defined inline:

<xsd:simpleType name="timeValueType">
  <xsd:restriction base="xsd:token">
    <xsd:pattern value="\d{2}:\d{2}"/>
  </xsd:restriction>
</xsd:simpleType>

<xsd:complexType name="timeType">
  <xsd:simpleContent>
    <xsd:extension base="timeValueType">
      <xsd:attribute name="format">
        <xsd:simpleType>
          <xsd:restriction base="xsd:token">
            <xsd:enumeration value="seconds"/>
            <xsd:enumeration value="minutes"/>
            <xsd:enumeration value="hours"/>
          </xsd:restriction>
        </xsd:simpleType>
      </xsd:attribute>
    </xsd:extension>
  </xsd:simpleContent>
</xsd:complexType>