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Forest Markup / Metadata Language FML. For Discussion among NEFIS Partners Tim Richards EFI / Conservation Technology Ltd NEFIS Midterm Meeting Vienna, 24-25 March 2004. Interoperability & Markup Languages - Revisited. Interoperability – what is it? XML – what is it?
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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 Meeting Vienna 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 Meeting Vienna May 2004 FML
Interoperability – what is it? • The ability for two or more (independently-developed) (software) components to: • interactmeaningfully • Communicate meaningfully • Exchange data or services [After Moh in Bonn] NEFIS Mid-term Meeting Vienna 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 Meeting Vienna May 2004 FML
data markup tag element 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> NEFIS Mid-term Meeting Vienna 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 Meeting Vienna 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 Meeting Vienna 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 Meeting Vienna 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 Meeting Vienna 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 Meeting Vienna 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 Meeting Vienna 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 Meeting Vienna May 2004 FML
DC expressed in XML • Example dc record in XML dc: Dublin Core “Namespace” NEFIS Mid-term Meeting Vienna 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 Meeting Vienna 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 Meeting Vienna May 2004 FML
Simple DC XML Schema • Link to DC Simple Schema DCMI XML Recommendation NEFIS Mid-term Meeting Vienna May 2004 FML
FML Schema XML Validation – conforms to the standard DC Schema Simple DC Simple DC + FML NEFIS Mid-term Meeting Vienna May 2004 FML
Dynamic Metadata Tool Online FML Schema Dynamic Metadata Software Tool Information Resource interprets describes produces Structure validated against FML Metadata Document NEFIS Mid-term Meeting Vienna May 2004 FML
Dynamic Data Tool Online FML Schema Data Export Tool Information Resource interprets extracts produces Structure validated against FML Data Document NEFIS Mid-term Meeting Vienna May 2004 FML
Natural Progression from EFIS Metadata Metadata Content In Metadata Definition efisSchema.xml XML Parser HTML Form XML Constructor RDBMS Metadata Content Repository HTML Form XML Parser NEFIS Mid-term Meeting Vienna May 2004 FML Metadata Out
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 Meeting Vienna 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 Meeting Vienna 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 Meeting Vienna May 2004 FML
Where now FML? • If the EU (or wider) forest community wants FML it should: • Make a strong case for FML and FML Tools • See what is out there that can already be used – such as EML • Secure funding to design and implement FML and FML Tools • Make it an Open Source Project from the outset ! NEFIS Mid-term Meeting Vienna May 2004 FML