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 !