NEFIS Mid-term MeetingVienna May 2004
FML
Forest Markup / MetadataLanguage
FML
For Discussion among NEFIS Partners
Tim Richards
EFI / Conservation Technology Ltd
NEFIS Midterm Meeting
Vienna, 24-25 March 2004
NEFIS Mid-term MeetingVienna May 2004
FML
Interoperability & Markup Languages - Revisited
• Interoperability – what is it?
• XML – what is it?
• XML Schema – what is it?
• FML – what could it be?
NEFIS Mid-term MeetingVienna May 2004
FML
Interoperability – what is it?
– The ability for two or more (independently-developed) (software) components to:• interact meaningfully
• Communicate meaningfully
• Exchange data or services
[After Moh in Bonn]
NEFIS Mid-term MeetingVienna May 2004
FML
Achieving Interoperability• Interoperability is difficult to achieve
because of heterogeneity -• Components are:
– written in different programming languages– running on different hardware platforms– running on different operating systems– using different data representations– using different control models– implementing different semantics or semantic
interpretations– implementing duplicate functionality– implementing conflicting functionality
[After Moh in Bonn]
NEFIS Mid-term MeetingVienna May 2004
FML
XML – what is it?
• eXtensible Markup Language– Meta markup language for text documents
• No fixed set of tags
– Data are included as strings of text which are surrounded by text markup that describes the data, e.g.
• <name>Cyril Hart</name>
element
markup tagdata
NEFIS Mid-term MeetingVienna May 2004
FML
XML
• XML is a meta-markup language– XML is completely open, you can define whatever
tags you want to. There is a need to constrain it.– Can be used to define an XML dialect that is specific
to a subject domain, such as forests, by a community agreeing on a standard set of tags with defined relationships. The community defines the XML dialect.
– XML is extensible and can be easily extended as and when required.
NEFIS Mid-term MeetingVienna May 2004
FML
Related XML Technologies
• XML is straightforward but belongs to a complex set of related technologies, including:– XML Schema Definition – provides constraints for
XML documents– Document Type Definitions– eXtensible Stylesheet Language – XSL– XQuery– XPath– XLinks– XPointers– XSL Formatting Objects (XSL-FO)
NEFIS Mid-term MeetingVienna May 2004
FML
Uses of XML
• Uses of XML– As a document format
– As a data format• For storing data / metadata• For transmitting data / metadata between systems
NEFIS Mid-term MeetingVienna May 2004
FML
XML Dialects
• Examples of XML dialects include:– Geography Markup Language (GML)– ESRI’s ArcXML– Scaleable Vector Graphics (SVG)– MathML– Ecology Metadata Language (EML)– Forest Markup Language ? What is that?
NEFIS Mid-term MeetingVienna May 2004
FML
FML
• What could FML do for the forest community?– FML could provide:
• an explicit and extensible definition of forest metadata – a standard
• a platform independent medium for the transfer of forest metadata - interoperability
• an explicit and extensible meta description for forest data – a standard
• A platform independent medium for the transfer of forest data - interoperability
NEFIS Mid-term MeetingVienna May 2004
FML
Purpose of FML
• “To provide the ecological forest community with an extensible, flexible, metadata standard for use in data analysis and archiving that will allow automated machine processing, searching and retrieval.”
Source – Ecological Metadata Language (EML) http://knb.ecoinformatics.org/
EML is defined in XML Schema as a set of related modules.
NEFIS Mid-term MeetingVienna May 2004
FML
FML Features
• FML’s main features could be:– Modularity – thus extensible– Detailed Structure – to enable machine processing– Compatibility – where possible adopts syntax of other
metadata standards – DC, GML, FGDC, etc– Strong Typing – by being implemented in XML
Schema– Difference between the content model (English) and
the syntax implementation (XML)
[After the EML features]
NEFIS Mid-term MeetingVienna May 2004
FML
DC expressed in XML
• Example dc record in XML
dc: Dublin Core “Namespace”
NEFIS Mid-term MeetingVienna May 2004
FML
DC expressed in XML
• DC publisher element qualified with a NEFIS address and namespace
extensibility
How to specify the tags ...
NEFIS Mid-term MeetingVienna May 2004
FML
XML Schema
• XML Schema – “... formalisation of the constraints, expressed as rules
or a model of structure, that apply to a class of XML documents” – a definition of FML
– Documentation• used to document xml definitions and provide an explicit
reference
– Validation• used to validate XML documents to ensure they conform to
the reference
NEFIS Mid-term MeetingVienna May 2004
FML
Simple DC XML Schema
• Link to DC Simple Schema
DCMI XML Recommendation
NEFIS Mid-term MeetingVienna May 2004
FML
XML Validation – conforms to the standard
DC Schema Simple DC
Simple DC + FMLFML Schema
NEFIS Mid-term MeetingVienna May 2004
FML
Dynamic Metadata Tool
OnlineFML Schema
Dynamic MetadataSoftware
Tool
FMLMetadataDocument
Information Resource
interprets describes
produces
Structure validatedagainst
NEFIS Mid-term MeetingVienna May 2004
FML
Dynamic Data Tool
OnlineFML Schema
Data ExportTool
FMLData
Document
Information Resource
interprets extracts
produces
Structure validatedagainst
NEFIS Mid-term MeetingVienna May 2004
FML
Natural Progression from EFIS Metadata
RDBMSMetadata Content
Repository
Metadata Content In
XML Parser
Metadata DefinitionefisSchema.xml
HTML Form
XML ParserHTML Form
Metadata Out
XML Constructor
NEFIS Mid-term MeetingVienna May 2004
FML
For example : EML Modules• Ecological Metadata Language
– Root level• Metadata container & base information
– Top level resources• Dataset module• Literature module• Software module• Protocol module
– Supporting modules• Access module• Physical module• Party module• Coverage module• Methods module
– Data organisation• Entity module• Attribute module• Constraint module
– Entity types• Data table module• Spatial raster module• Spatial vector module• Stored procedure module
– Utility modules• Text module• Dependency chart
FML could be comprised of a similar set of modules, streamlined for forests rather than ecology.
For example FML might include a module on forest models.
NEFIS Mid-term MeetingVienna May 2004
FML
Open Source EML Tools
• EML Schema
• Morpho Metadata Client Tool– dynamically generated from the EML Schema
• Metacat Metadata Server– XML database
NEFIS Mid-term MeetingVienna May 2004
FML
Open FML Q’s: For Discussion
• Q. Is XML/FML relevant to NEFIS and the wider EU forest agenda?
• A. Suggest yes…• Q. Would FML enhance interoperability issues in
the European (and wider) forest community?• A. Suggest yes…• Q. Are the problems that are addressed
syntactic or semantic?• A. Mainly syntactic, some semantics?
[After Moh in Bonn]
NEFIS Mid-term MeetingVienna May 2004
FML
Where now FML?
• If the EU (or wider) forest community wants FML it should:
1. Make a strong case for FML and FML Tools
2. See what is out there that can already be used – such as EML
3. Secure funding to design and implement FML and FML Tools
4. Make it an Open Source Project from the outset !