XML Schema for a bit complicated record

Question

I am having a problem building a schema for this XML:

<record>
    <field index="1">data</field>
    <field index="2">data</field>
    <field index="3">data</field>
    <field index="4">data</field>
    <field index="5">data</field>
    <field index="6">data</field>
    <group index="7">
        <member index="1">data</member>
        <member index="2">data</member>
    </group>
    <field index="8">data</field>
    <field index="9">data</field>
    <group index="10">
        <member index="1">data</member>
    </group>
    <field index="11">data</field>
    <field index="12">data</field>
    <field index="13">data</field>
    <field index="14">data</field>
    <field index="15">data</field>
    <field index="16">data</field>
    <field index="17">data</field>
</record>

---

The problem is that, I don't know to build a schema for the "field" elements, I have many elements with the same name "field" but with different attributes "index".

Also I am having a problem building a schema for the multi values inside the the tag group.

Answer 1

Welcome, for the field, you could define something along these lines:

<xsd:element name="field" type="FieldType"/>
<xsd:complexType name="FieldType>
  <xsd:simpleContent>
    <xsd:extension base="xsd:string">
      <xsd:attribute name="index" type="xsd:integer" />
    </xsd:extension>
  </xsd:simpleContent>
</xsd:complexType>

As for the group, you have to use a sequence:

<xsd:element name="group" type="GroupType" />
<xsd:complexType name="GroupType">
  <xsd:sequence>
    <xsd:element name="member" type="MemberType" minOccurs="1" maxOccurs="unbounded" />
  </xsd:sequence>
  <xsd:attribute name="index" type="xsd:integer" />
</xsd:complexType>

I assumed you must have at least one member for each group. Also, you should define the MemberType. I omitted it because it's almost identical to the FieldType above mentioned.

Answer 2

Hi thanks for the help.

I I tried this. However, the problem is that field with attribute index = "1" means name , and field index = "2" for instance means DOB field index = "3" means email .. etc

which means I have to define all the field elements for all the attributes in the record, which I still don't know how to do it .. because I have multiple elements with the same name "field" but however, different values for attribute "index".

thanks again.

Answer 3

You've just found out why this is a bad design for a schema. There's no way to associate a type with an index. You should have individual element names, with individual types. For instance:

<person xsi:noNamespaceSchemaLocation="Person.xsd" 
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;
    <name>
        <first>John</first>
        <last>Saunders</last>
    </name>
    <dob>1967-08-13</dob>
    <email>[email protected]</email>
</person>

Could come from the following schema:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" 
     elementFormDefault="qualified" attributeFormDefault="unqualified">
    <xs:element name="person">
        <xs:annotation>
            <xs:documentation>A person</xs:documentation>
        </xs:annotation>
        <xs:complexType>
            <xs:sequence>
                <xs:element name="name">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element name="first" type="xs:string"/>
                            <xs:element name="last" type="xs:string"/>
                        </xs:sequence>
                    </xs:complexType>
                </xs:element>
                <xs:element name="dob" type="xs:date"/>
                <xs:element name="email">
                    <xs:simpleType>
                        <xs:restriction base="xs:token"/>
                    </xs:simpleType>
                </xs:element>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
</xs:schema>

This sort of thing can restrict particular elements to particular data types, and more. The sort of thing you have cannot restrict the type of particular elements because they all need to support any data type.