Validation of Metadata XML files SeaDataNet Training, June 2008 Presented by with contributions from Karen Vickers (BODC) Presented by Michèle Fichaut (IFREMER) with contributions from Karen Vickers (BODC)

Validation of Metadata XML files Overview 1.Background 2.Schema development 3.Validation of XML files 4.Planning validation developments 5.Support

Background Background The exchange of metadata records between partners and the directory managers will use ISO compliant XML files. ISO is increasingly important in the international marine community. It provides Interoperability between SeaDataNet and the rest of the Marine community. It is essential that these ISO XML files conform to SeaDataNet standards. To support these standards, ISO compliant schemas and validation tools have been developed first in the frame of the Sea-Search EU project and then by the SeaDataNet Technical Task Team (TTT). These tools enable XML files to be validated by the partners before sending them to the directory managers.

Background Activity diagram for creating and loading EDMED XML documents SeaDataNet PartnerBODC Create EDMED XML files Validate XML files Send XML files to BODC Quality Control EDMED entries Validate XML files Make EDMED entries available on website modifications to partner Partner updates their records with changes Load metadata into EDMED database

Schema development XML schemas During the development of the validation system, it became apparent that the XML Schema language was not powerful enough to provide the required validation. To meet the validation requirements, Schematron was adopted. Schematron is a rule-based validation language for defining tests for XML. The XML schemas go through 3 phases of development: 1.Definition of the schemas using the XML Schema language to create XSD files, e.g. EDMED_V1.1.xsd. These are called the “unextended schemas”. 2.Addition of Schematron code to the XSD files to create a template, e.g. EDMED_V1.1_1.xsd. 3.Automatic update of the template to include tests against controlled vocabulary lists, e.g. EDMED_V1.1_1.1.xsd. These are called the “extended schemas”.

Schema development Lifecycle of extended schema Definition of ISO XML schema model (SeaDataNet TTT) Development of XML unextended schema (SeaDataNet TTT) Development of extended XML schema using Schematron (BODC) Publication of new extended XML schema, including automatic update of controlled vocabulary lists (RNODC) Enhancement requests and bug reporting

Schema development The schema name indicates its version: directory_sdn_vx.x_y.y.xsd where directory is EDMED, CDI, CSR or EDMERP x.x is the unextended version of the schema y.y is the extended version of the schema All published versions are maintained at: e.g. sdcdi/cdi_sdn_v1.3_1.1.xsd

Validation of XML files Partners should validate their XML documents before sending them to the directory manager Two ways of validating are possible: 1.Upload the XML file into the SeaDataNet Web Validation tool at 2.Use your local XML validator – this MUST support Schematron, e.g. OxYgen XML editor 9.2

Validation of XML files Web Validation services ( provides the following functionality: User interface to upload and validate file Scheduled BODC and MARIS web services control to perform automatic XML schema update as controlled vocabulary lists are updated. XML schema versioning (when automatic update occurs) Maintenance of all versions of the schema (xsd-files) because the URL will be embedded in XML documents notification to BODC with attached updated XML Schemas so that BODC can check them For partners wishing to validate using their local application (e.g. OxYgen XML Editor 9.2), the schema can either be downloaded from the web site, or the full URL can be specified in the XML document

SeaDataNet XML Validator (1)

SeaDataNet XML Validator (2)

SeaDataNet XML Validator (3)

SeaDataNet XML Validator (4)

SeaDataNet XML Validator (5)

Planned validation developments Release V1 Web Validation Service is scheduled for June The following developments are expected in future releases: Review and agree on the limit of free text fields, e.g. EDMED dataset name. Support of more than one file in Web validation tool. Improved location of errors in XML file. Support for EDIOS XML files. Resolution of reported bugs. Timescales yet to be agreed by the SeaDataNet Technical Task Team (TTT).

Support For further support, or to report problems, Your feedback will be appreciated.

Practical work to-morrow With Mikado, you will create EDMED, CSR and CDI XML files. You will have to upload them on the validator and see if they are valid or not.

Any questions?