1. MEDIN Standards Workshop
Standards / XML / Validation /
Transformation / ESRI

2. Introduction
– XML
– Schema and Validation
• XSD Schema
• Schematron
– Transformation
• Stylesheets
– ESRI ArcGIS
– Search

3. XML

4. XML
•Extensible Markup Language (XML)
– A metamarkup language
– The basic unit is called an element
Element
<tag attribute="attribute value">element value</tag>
Attribute
Opening tag Closing tag
– Apparently similar to HTML but…

5. Metamarkup?
•What does metamarkup mean?
– There is no predefined and fixed set of tags
for XML
– XML allows implementers to define their
own set of tags to meet their needs
Examples
• Office Open XML (ISO/IEC 29500)
• Geography Markup Language (ISO 19136)

6. Markup – ESRI ArcGIS 10 XML
<idCitation>
<resTitle>Title</resTitle>
<date>
<createDate>20110906</createDate>
</date>
</idCitation>

7. Markup – ISO 19139 XML
<gmd:citation>
<gmd:CI_Citation>
<gmd:title>
<gco:CharacterString>Title</gco:CharacterString>
</gmd:title>
<gmd:date>
<gmd:CI_Date>
<gmd:date>
<gco:Date>2011-09-06</gco:Date>
</gmd:date>
<gmd:dateType>
<gmd:CI_DateTypeCode
codeList="...#CI_DateTypeCode"
codeListValue="creation">creation</gmd:CI_DateTypeCode>
</gmd:dateType>
</gmd:CI_Date>
</gmd:date>
</gmd:CI_Citation>
</gmd:citation>

8. Well-Formed
•XML has strict rules, e.g.:
– There must be one, and only one root
element
– All elements must have an opening
and closing tag
– Element names are case sensitive:
• <citation/> is different from <Citation/>
– XML conforming to the rules is said to
be well-formed

9. Well-Formed
<idCitation>
<resTitle>Title</resTitle>
<date>
<createDate>20110906</createDate>
</date>
</idCitation>
<idCitation> Opening and closing tags
<resTitle>Title</ResTitle> are different
<date>
Two root elements <createDate>20110906 No closing tag
</date>
</idCitation>
<idPurp>Summary</idPurp>

10. Structure
•The markup defines data structure:
– It signifies which elements are
associated
– It can define semantics:
<date>
<createDate>20110906</createDate>
</date>
– It says nothing about how to display
data (there are exceptions to this rule)

11. XML is machine readable
•And…
– Human readable… honestly

13. Schema and Validation

14. Schema
•Schemas document the elements that are
permitted in an XML application
– XML that conforms to a schema is said
to be schema-valid
– XML that does not conform to a
schema is said to be invalid

15. XML Schema Definition Language
<xs:complexType name="CI_Citation_Type">
...
<xs:complexContent>
<xs:extension base="gco:AbstractObject_Type">
<xs:sequence>
<xs:element name="title"
type="gco:CharacterString_PropertyType"/>
<xs:element name="alternateTitle"
type="gco:CharacterString_PropertyType"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="date"
type="gmd:CI_Date_PropertyType"
maxOccurs="unbounded"/>
...
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>

16. Markup – ISO 19139 XML
<gmd:citation>
<gmd:CI_Citation>
<gmd:title>
<gco:CharacterString>Title</gco:CharacterString>
</gmd:title>
<gmd:date>
<gmd:CI_Date>
<gmd:date>
<gco:Date>2011-09-06</gco:Date>
</gmd:date>
<gmd:dateType>
<gmd:CI_DateTypeCode
codeList="...#CI_DateTypeCode"
codeListValue="creation">creation</gmd:CI_DateTypeCode>
</gmd:dateType>
</gmd:CI_Date>
</gmd:date>
</gmd:CI_Citation>
</gmd:citation>

17. Schematron
•Schematron is:
– A schema language for XML
• Document Schema Definition Language
(DSDL)
– Written in XML
– It’s an ISO Standard – ISO 19757-3
Find out more at: http://www.schematron.com/

18. Why use Schematron?
•XSD schema is unable to test some
constraints:
– The ability to specify a choice of
attributes
– The ability to vary the content model
based on the value of an element or
attribute (this sort of constraint is
common in the ISO 19115 logical
model)
•Implementing profiles (e.g. MEDIN):
– With Schematron there’s no need to
edit the underlying standardised XSD

20. Validation Workflow
XSD Schema Validation
Schematron Validation

21. Validation Tools
Select profile
XSD Schema
Schematron
schemas

22. Transformation

23. XSLT
•Extensible Stylesheet Language
Transformations (XSLT)
– Specifies rules for transforming one
XML instance into another XML
instance
– The output XML instance will have a
different structure from the input XML
instance

24. ESRI XML to MEDIN XML
•MEDIN XML must be follow the ISO 19139 XML
encoding
– Users may wish to use other software to
create and manage metadata (e.g. ESRI
desktop GIS)
– ESRI software manages metadata using XML
– The XML does not following the ISO 19139
standard
– The XML can be transformed to ISO 19139
– MEDIN provides resources to support this

25. Stylesheet Tools

26. ESRI ArcGIS

27. Versions
•ArcGIS 9
– FGDC / ISO
•ArcGIS 10
– ESRI Core Metadata
– Both use XML encoding
– The encodings are slightly different
– Why the change at version 10?

28. ESRI ArcCatalog – Options

29. ESRI ArcCatalog

30. Transformation
e.g. Internal use e.g. External / Publish to DAC
ArcGIS 9 Metadata
Transformation MEDIN Metadata
ArcGIS 10 Metadata

31. Transform Options
•Use MEDIN stylesheets
– ArcGIS 9 version
– ArcGIS 10 version (or the Validate
button)
•Implementation
– Any XSL stylesheet processor
(version1.0), e.g:
• ArcGIS 9 or 10 ArcToolBox
• Metadata Maestro