XML and Excel

Pages in this article

1. What is XML
2. Characteristics of XML
3. Structure of XML
4. XML Schemas
5. XML in Excel
6. XML Validation
7. Conclusion

XML Schemas

An XML file can have a schema definition (XSD) attached to it. A schema definition determines the structure of the XML file. Other things an XSD file may define are:

• The format of the data inside an element (string, number, etcetera)
• Whether or not an element is mandatory
• If an element can be repeated.

To attach an XML file to a schema a reference to the schema file must be included inside the XML file. The schema reference can be added as an attribute of the root element, like this:

<companies xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="Schema.xsd">

The text in Bold builds the reference to the schema file schema.xsd, which in this example must reside in the same folder as the xml file. Without getting into the details of the exact syntax of a schema definition here is an example tied to the file test1_en.xml:

Listing 1: Schema.xsd

<?xml version='1.0' encoding='UTF-16'?>
<!-- XmlMap.DataBinding.SourceUrl: C:\Data\OfficeMagazine\XML\test2.xml --> <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">    <xsd:element name="companies">
       <xsd:complexType>
          <xsd:sequence minOccurs="0">             <xsd:element minOccurs="0" name="company" >                <xsd:complexType>
                   <xsd:sequence minOccurs="0">                      <xsd:element minOccurs="0" type="xsd:string" name="companyname" />                      <xsd:element minOccurs="0" maxOccurs="unbounded" name="employee" >                         <xsd:complexType>                            <xsd:sequence minOccurs="0">                               <xsd:element minOccurs="1" type="xsd:string" name="code" />                               <xsd:element minOccurs="1" type="xsd:string" name="name" />                               <xsd:element minOccurs="0" type="xsd:string" name="street" />                               <xsd:element minOccurs="0" type="xsd:string" name="Houseno" />                               <xsd:element minOccurs="0" type="xsd:string" name="areacode" />                               <xsd:element minOccurs="0" type="xsd:string" name="place" />                               <xsd:element minOccurs="0" type="xsd:string" name="phone" />                            </xsd:sequence>                         </xsd:complexType>
                      </xsd:element>
                   </xsd:sequence>
                </xsd:complexType>
             </xsd:element>
          </xsd:sequence>
       </xsd:complexType>
    </xsd:element>
 </xsd:schema>

Such a schema is obviously less easy to read than the accompanying XML file. More information on schemas.

Extensible Stylesheets

With Extensible Stylesheets (xsl files) xml files can be converted to other formats, e.g. to SpreadsheetML, the XML format that supports spreadsheets. How these stylesheets work is outside the scope of this article. More information about extensible stylesheets by the w3c organisation.