1

Part 6

Introduction to HALE software (acknowledgement goes to T. Reitz, S. Templer – Fraunhofer IGD, Darmstadt, Germany)

2 Introduction to HALE

• HUMBOLDT Alignment Editor (HALE) is a tool to create mappings between different data models/schemes

• Distributed under Open Source GNU LGPL licence.

3 Introduction to HALE

• Initially developed in the HUMBOLDT project

• Work is continued in other research projects and in the data harmonisation panel

4 Introduction to HALE

• HALE enables to transform and harmonise spatial data, with a focus on highly complex data sets

• HALE can be used for defining and evaluating conceptual schema mappings, to create logically and semantically consistent mappings, that makes mappings easier to understand and to maintain

• HALE documents the schema transformation process and its impact on data quality

• HALE provides a unique declarative approach to making interactive schema mapping a less daunting task

5 Introduction to HALE

• HALE provides a rich, textual and graphical interface specifically adopted for GIS Experts

• HALE gives instant feedback about the progress of mapping data from one schema to another, enabling the understanding of the transformation process

6 Introduction to HALE

• Direct transformation of sample dataset

• Visual feedbacks:

– completeness of mapping

– geometry transformation

7 Introduction to HALE

• On-line validation step by step

• Comparison between source and target data

8 Main workflow HALE 1. Import the schema of the source data you want to map

2. Import the target schema

3. Import a source data set (optional)

4. Identify the relevant target types

5. Identify and add the relations between source an target types

6. For each type relation analyze

– What information is present in the source classe(s)?

– What information is needed in the target class?

– How can the target properties be populated from the source?

to identify the relations between the source and target properties, then add them to the mapping.

7. For each change to the mapping, verify if the transformation result meets your expectations (optional, needs source data)

8. Save the transformed data to a file (optional, needs source data)

9. or, alternatively, use the defined mapping to transform external data.

9 Workbench HALE

• Perspectives:

– Group of views in the workbench window

– Predefined (default, data, map, Thorsten)

– Customizable (adding/remove views) - Savable

• Views:

– Visual component within the workbench

– to represent a certain aspect of the current project, displaying information and possibly also allowing to manipulate it

10 Schema explorer view

Viewing the structure of the source and target schemas

11 Schema elements

Types

Groups

Properties

12 Icon augmentations

On top of schema element icon:

13 Contexts

Name of a schema element is displayed in brackets:

• Source schema contexts

• Target schema contexts

14 Cardinality – Population

• Cardinality of properties

• When source data are loaded information on the number of instances

15 Alignment

• Alignment is the mapping between source and target schemas

• It defines relations between source and target entities (types or properties)

• Relations represented by mapping cell

• Property relations only take effect in the context of a type relation. This means first a type relation must be defined, then property relations between the involved types can be specified.

16 Mapping cell

• Atomic relation contained in an Alignment

• A cell specifies:

– source and target entities

– function and possibly parameters for the function.

• Cell priority in case two different relations map to a target entity.

17 Functions • Describes a relation between well-defined inputs and

outputs (see functions view for list)

– Type relations: between source and target types, f.e.:

• Retype: Maps one source type to one target type

• Merge: Merges multiple instances of the source type into one instance of the target type, based on one or more matching properties

• Join: Joins multiple instances of different source types into one instance of the target type, based on one or more matching properties

• Create: Create instances of a specific schema type

– Property relations: between source and target properties

• General: date extraction, formatted string, rename, assign, classification,…

• Geometric: ordinates to point, length, area, extent, centroid, network expansion

• Groovy: scripting possibility

• INSPIRE: INSPIRE identifier, Geographical Name

• Numeric: Mathematical Expression, sequential ID

18 Schema tasks in HALE

• Loading source and target schemas

– From files: XML, GML, CSV, Shapefile

– From WFS

– From preset (INSPIRE application schemas, Annex I)

– From URL, Annex II and III, f.e. : http://inspire.ec.europa.eu/draft-schemas/so/3.0rc3/Soil.xsd

• Defining contexts on elements

• Customize mapping relevant types of source/target schema

• Loading codelists from INSPIRE register, f.e.: http://inspire.ec.europa.eu/codelist/EnvironmentalDomain/EnvironmentalDomain.en.xml

19 Data tasks in HALE

• Working with source dataset/subset

• Export transformed data

• Validation transformed data (inside HALE – exported data)

• Transform external data

• Styling of data for display in map view

20 Alignment tasks in HALE

• Mapping schema elements by:

– Add new relation command (Edit Menu)

– Select source and target element and press

• Editing a mapping cell

• Deleting a relation

21 Save your work

• Save Alignment Project as from File menu, options:

22 Useful links

hale is Open Source Software and licensed using the LGPL 3.0.

Online Hale user guide:

http://hale.igd.fraunhofer.de/2.8.0/help/index.jsp

Find out more about the data harmonisation panel: http://www.dhpanel.eu

HALE community site: http://www.esdi-community.eu/projects/show/hale

Public user and developer mailing list:

dev@esdi-humboldt.eu