XSD reference a type defined within the same file

Question

I an trying to create an XSD, to define complex types to be referenced in other XSDs. So far so good. Within this XSD (playlist.xsd) I have one main complexType "playlistType". I want the playlistType to be able to contain multiple instances of an element of type 'secondaryEventType', which I am trying to define as a separate complexType within the same XSD file.

However, when I come to try to create the 'secondaryEvent' element within the 'playlistType' I am continuously getting the error message : "'secondaryEventType' must refer to an existing simple or complex type.". I have tried placing the definition of the 'secondaryEventType' both before and after the definition of the main 'playlistType', I have tried with and without the xs: prefix.

What am I doing wrong?

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsB="baseTypes" targetNamespace="playlist">
    <xs:import namespace="baseTypes" schemaLocation="baseTypes.xsd"/>

    <xs:complexType name="secondaryEventType">
        <xs:sequence>
            <xs:element name="type">
                <xs:simpleType>
                    <xs:restriction base="xs:string">
                        <xs:enumeration value="graphic"/>
                        <xs:enumeration value="bug"/>
                        <xs:enumeration value="voiceover"/>
                        <xs:enumeration value="subtitle"/>
                        <xs:enumeration value="addInsertionAvail"/>
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="playlistType">
        <xs:sequence>
            <xs:element name="primaryEvent" minOccurs="1" maxOccurs="unbounded">
                <xs:complexType>
                    <xs:sequence>
                        <xs:element name="eventID" type="xsB:guidType"/>
                        <xs:element name="eventTitle" type="xs:string"/>
                        <xs:element name="mediaID">
                            <xs:simpleType>
                                <xs:restriction base="xs:string">
                                    <xs:minLength value="2"/>
                                    <xs:pattern value="\S+"/>
                                </xs:restriction>
                            </xs:simpleType>
                        </xs:element>
                        <xs:element name="SOM" type="xsB:timecodeType"/>
                        <xs:element name="DUR" type="xsB:timecodeType"/>
                        <xs:element name="transition" minOccurs="0">
                            <xs:simpleType>
                                <xs:restriction base="xs:string">
                                    <xs:enumeration value="cut"/>
                                    <xs:enumeration value="dissolve"/>
                                    <xs:enumeration value="fade"/>
                                </xs:restriction>
                            </xs:simpleType>
                        </xs:element>
                        <xs:element name="transitionDuration" type="xsB:timecodeType" minOccurs="0"/>
                        <xs:element name="secondaryEvent" type="secondaryEventType" minOccurs="0" maxOccurs="unbounded"/>
<!-- Error occurs Here -->
                    </xs:sequence>
                </xs:complexType>
            </xs:element>
        </xs:sequence>
    </xs:complexType>

</xs:schema>

Answer 1

Reference the name of the playlistType complex type using the namespace given by the XSD's targetNamespace. Your updated, working XSD follows...

Stub baseTypes.xsd:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           xmlns:xsB="baseTypes"
           targetNamespace="baseTypes">
  <xs:complexType name="guidType"/>
  <xs:complexType name="timecodeType"/>
</xs:schema>

Working main XSD:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           xmlns:xsB="baseTypes"
           xmlns:pl="playlist"
           targetNamespace="playlist">
  <xs:import namespace="baseTypes" schemaLocation="baseTypes.xsd"/>
  <xs:complexType name="secondaryEventType">
    <xs:sequence>
      <xs:element name="type">
        <xs:simpleType>
          <xs:restriction base="xs:string">
            <xs:enumeration value="graphic"/>
            <xs:enumeration value="bug"/>
            <xs:enumeration value="voiceover"/>
            <xs:enumeration value="subtitle"/>
            <xs:enumeration value="addInsertionAvail"/>
          </xs:restriction>
        </xs:simpleType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>
  <xs:complexType name="playlistType">
    <xs:sequence>
      <xs:element name="primaryEvent"
                  minOccurs="1"
                  maxOccurs="unbounded">
        <xs:complexType>
          <xs:sequence>
            <xs:element name="eventID" type="xsB:guidType"/>
            <xs:element name="eventTitle" type="xs:string"/>
            <xs:element name="mediaID">
              <xs:simpleType>
                <xs:restriction base="xs:string">
                  <xs:minLength value="2"/>
                  <xs:pattern value="\S+"/>
                </xs:restriction>
              </xs:simpleType>
            </xs:element>
            <xs:element name="SOM" type="xsB:timecodeType"/>
            <xs:element name="DUR" type="xsB:timecodeType"/>
            <xs:element name="transition" minOccurs="0">
              <xs:simpleType>
                <xs:restriction base="xs:string">
                  <xs:enumeration value="cut"/>
                  <xs:enumeration value="dissolve"/>
                  <xs:enumeration value="fade"/>
                </xs:restriction>
              </xs:simpleType>
            </xs:element>
            <xs:element name="transitionDuration"
                        type="xsB:timecodeType"
                        minOccurs="0"/>
            <xs:element name="secondaryEvent"
                        type="pl:secondaryEventType"
                        minOccurs="0"
                        maxOccurs="unbounded"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>
</xs:schema>