XSLT FOR

INSPIRE TRANSFORMATION

In ESDIN by Kadaster

KEN - Paris - Oct 8, 2013

About MeIndependent Open Source Geospatial Professional

Secretary OSGeo Dutch Local Chapter Member of the Dutch OpenGeoGroep

Just van den Broeckejust@justobjects.nl www.justobjects.nl

OPEN SOURCEFOR INSPIRE

MAKES SENSE

Picture from: http://cameronshorter.blogspot.com

3. COMMUNITYENABLER

INSPIRE Projects

2009-2011 Dutch Kadaster - Kademo Lab - EURADIN and ESDINinspire.kademo.nl - Ebrahim Hemmatnia - Ko van Raamsdonk - Haico van der Vegt

2011 Kadaster - INSPIRE Transformations Key Registries Data CP,AD,TN,GN,HY inspire.kademo.nl

2011-2013 PDOK - National GeoPortal with INSPIRE www.pdok.nl

2010-now - cooperation deegree community - Lat/lon, Occam Labs www.deegree.org

Talk 1

XSLT - what, how

ESDIN - INSPIRE transformation Kadaster

Talk 2

formalizing approach from Talk 1

using Stetl framework for INSPIRE

AGENDA

EXTENSIBLE STYLESHEET LANGUAGE (XSL)

Origins : SGML+DSSSL ==> XSL for XML documents

W3C XSL Working Group

First called “XSL”, then split into three standards

1.XSL Transformations (XSLT)

2.XSL Formatting Objects “FOP”

3.XPath - XML Navigation/Query Language

PRINCIPLE

The XSLT processor takes one or more XML source documents, plus one or more XSLT stylesheet modules, and processes them to produce an output document. The XSLT stylesheet contains a collection of template rules: instructions and other directives that guide the processor in the production of the output document.

http://en.wikipedia.org/wiki/XSLT

EXAMPLE

http://en.wikipedia.org/wiki/XSLT

Input XML Document

EXAMPLE

http://en.wikipedia.org/wiki/XSLT

XSLT Stylesheet Document

EXAMPLE

http://en.wikipedia.org/wiki/XSLT

XML Result Document

EXAMPLE

http://en.wikipedia.org/wiki/XSLT

HTML Generation with Alternative XSLT Stylesheet

EXAMPLE

http://en.wikipedia.org/wiki/XSLT

(X)HTML Result Document (alternative Stylesheet)

XSLT PRINCIPLES

Basically Tree Transformation

Input: well-formed XML document

Output: XML document or anything “text” (SQL!)

Declarative, rule-based, functional, recursive

But also: Structured and Procedural (named templates)

XSLT PRO’S

Well-established (sinds 1999)

stable standards

huge amount of knowledge on the web

Optimized XSLT tools in any programming language

XML-based, same base language as source/target docs

Compact, reusable stylesheets (ala subroutines)

Extension points for custom code

XSLT PRO’S CONT.

TEXT

IN THE BEGINNING...

"In the Beginning was the Command Line"

By Neal Stephensonhttp://www.cryptonomicon.com/beginning.html

XSLT CONS

Complex

intellectual challenge: thinking declarative/functional

poorly understood, often messy stylesheets

Poor scalability with large documents

No GUI

INSPIRE: only model transform (no coordinate transform)

IMPLEMENTATION

INSPIRE - WHAT

WFSWMSCSWWPS

.

.Local Data

INSPIRE Data

Web Services

INSPIRE - DATA THEMES

INSPIRE - TRANSFORMATIONS

source: Geonovum.nl

KADASTER - PHASE 1COMBINED TRANSFORMATION

On-the-fly Transformation

Offline Transformation

National Data

(Oracle)

Extract

Transform

Load (ETL)

INSPIRE Data

(PostGIS)

Web

Feature

Service

(WFS)

INSPIRE

GML

OSGeo - Bolsena - 2010

KADASTER - PHASE IIOFFLINE TRANSFORM + DEEGREE

INSPIRE

View Service

(WMS)

Extract

Transform

Load (ETL)

INSPIRE

Feature Store

(BLOB or Hybrid)

INSPIRE

Download Service

(WFS)

deegree 3

INSPIRE Publish

1) WFS-T

2) deegree loader

Configuration Data

- INSPIRE Data Themes (XSD)

- Data Mappings (XML)

- WMS Styling (SLD)

Kadaster Data

(Oracle)

KADASTER - PHASE IIREUSABLE ETL + SERVICES

INSPIRE

View Service

(WMS)

Extract

Transform

Load (ETL)

INSPIRE

Feature Store

(BLOB or Hybrid)

INSPIRE

Download Service

(WFS)

deegree 3

INSPIRE Publish

1) WFS-T

2) deegree loader

Configuration Data

- INSPIRE Data Themes (XSD)

- Data Mappings (XML)

- WMS Styling (SLD)

Kadaster Data

(Oracle)

ReusableSpecific

KADASTER - PHASE IIETL CHAIN

ETL CHAIN - TOOLS

• Extract

• internal tools: e.g. Oracle to Shapefile or XML

• Transform

• GDAL/OGR - Coordinate and create Simple Features (GML)

• XSLT - Model Transformation

• Load

• directly in PostGIS database

• via deegree FeatureStore Loader

• via WFS-T

SOFTWARE STACK

Architecture

PostGIS

WFS

deegree

LocalData

ScriptsGDALXSLT

Unix shell

ETL

INSPIRE Download/View Services

TomcatJava J2EE

Server

Heron Mapping Client

WFS-TFSLoad

WMS

SLD

data flow

API (web service) API

storage

ESDIN Test Framework

Now Stetl!

XSLT STRUCTURE

Local CP GMLto

INSPIRE SpatialDataset

Local CP GMLto

INSPIRE GML

GenerateCP INSPIRE GML

ReusableXSLT ScriptsReusable

XSLT Scripts

Theme CP

Local AU GMLto

INSPIRE SpatialDataset

Local AU GMLto

INSPIRE GML

GenerateAU INSPIRE GML

Theme AU

Local GN GMLto

INSPIRE SpatialDataset

Local GN GMLto

INSPIRE GML

GenerateGN INSPIRE GML

Theme GN

Called by All

Locally Specific XSL

GenericXSL

XSLT Template Call

XSLT - 3 MAIN STEPS/SCRIPTS

1.Generate Spatial Dataset GML Container (specific)

2.Extract data values from local OGR simple feature data (specific)

3. Call XSLT template per Theme Feature type (generic)

XSLT - STEP 1

XSLT - STEP 2

XSLT - STEP 3

XSLT - REUSE

THE “GUI”

validated file contentproject files

commands

run deegree

CONCLUSIONS

1.XSLT for INSPIRE (Model) transformations ? YES

2.XSLT shines in combination with OGR and PostGIS

3.Don’t Develop INSPIRE Transforms in isolation but in context of

your global INSPIRE SDI Architecture

4. Kadaster overall approach in ESDIN worked well

GETTING INVOLVED

INSPIRE @ OSGEO

http://lists.osgeo.org/mailman/listinfo/inspire-data

http://wiki.osgeo.org/wiki/INSPIRE_data_experiments

MAILING LIST

WIKI

LINKS

STETL

PROJECT SITE

DOCU DEMOS AND INFO

http://inspire.kademo.nl

http://inspire-foss.org

http://stetl.org