Question

I want to write an XML file that contains a root node called appointment_list. This root node should contain multiple child elements of type appointment_type.

I’ve written the schema below but I get the error:

s4s-elt-must-match.1: The content of ‘appointments_list’ must match
(annotation?, (simpleType | complexType)?, (unique | key | keyref)*)).
A problem was found starting at: element.

I know that I’m supposed to use one of the tokens it lists in the message but I don’t know which one. I’m new to XML. What I want is that the appointment_list root element contain multiple child appointment_type elements. How do I do that. Thanks 🙂

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs= "http://www.w3.org/2001/XMLSchema">

    <xs:simpleType name="priority">
        <xs:restriction base="xs:string">
            <xs:enumeration value="high"/>
            <xs:enumeration value="normal"/>
            <xs:enumeration value="low"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="appointment_type">
        <xs:sequence>
            <xs:element name="title" type="xs:string" minOccurs="1" />
            <xs:element name="description" type="xs:string" minOccurs="0"/>
            <xs:element name="appointment_date" type="xs:date" minOccurs="1"/>
            <xs:element name="appointment_time" type="xs:time" minOccurs="1"/>
            <xs:element name="appointment_priority" type="priority" minOccurs="0"/>
            <xs:element name="duration" minOccurs="0">
                <xs:simpleType>
                    <xs:restriction base="xs:integer">
                        <xs:minInclusive value="0"/>
                        <xs:maxInclusive value="24"/>
                    </xs:restriction>
                </xs:simpleType>
            </xs:element>
        </xs:sequence>
        <xs:attribute name="id" type="xs:positiveInteger" use="required"/>
    </xs:complexType>   

    <xs:element name="appointments_list">
            <xs:element name="appointment" type="appointment_type" maxOccurs="unbounded" />
    </xs:element>
</xs:schema>

Answer 1

An <xs:element> that contains elements must have a <xs:complexType> (or type attribute whose value is a complex type – like your <appointment> element).

A <xs:complexType> must have a group, e.g. <xs:sequence>.

<xs:element name="appointments_list">
  <xs:complexType>   
    <xs:sequence>   
      <xs:element name="appointment" type="appointment_type" maxOccurs="unbounded" />
    </xs:sequence>   
  </xs:complexType>   
</xs:element>