WDTF Validation

Validating WDTF documents

Using a specified format for data delivery, such as WDTF, provides an opportunity for the Bureau and data providers to test whether the documents comply with the selected format and its associated business rules. The process of testing a document's compliance to format rules is called validation.

In order to strengthen the use of the WDTF format there is a need to test documents for format compliance. The Bureau has developed a WDTF validating service to allow organisations to check if the data they are supplying can be interpreted correctly and is therefore compliant with WDTF.

The Bureau's WDTF validating service uses a HTML interface to enable manual validation of sample documents. As the validation service matures it will become a web service that enables automated validation of documents as part of the process for delivering WDTF data to the Bureau.

What needs to be validated?

A published data format details the structure and meaning of the content. This is also called the syntax and semantics. The syntax rules govern the form and structure of the text contained in a WDTF XML document. Being an XML document, a WDTF document must conform to the syntax rules for XML documents as well as the schemas included in WDTF. The semantic rules define the additional business requirements that define the meaning of the data. A simple semantic rule would be that rainfall should not be reported with units of kilo Pascals.

Validation tools in the WDTF release package

The WDTF distribution package includes an Apache ANT script for validating documents, this script can be installed and run on a local PC. The ANT script will test for XML well-formedness and compliance with the schemas inherited in WDTF, including the primary WDTF schema water.xsd. The ANT script is only able to apply schema level (syntactic) validation. While important in its own right, this level of validation does not enforce the business rules that ensure the usability of a document.

Validation services on the Bureau web site

The validation service allows you to upload and test a WDTF document online. The validation service tests syntactic and semantic compliance. Syntactic compliance is tested using the Apache ANT script as contained in the WDTF distribution package. Semantic compliance is tested using Schematron to apply rules and test against the WDTF defined vocabularies.

Our existing web-based WDTF validation service provides a significantly enhanced ability to test WDTF documents. The validator will be developed to apply the WDTF business rules with increasing rigour.

Validation service versioning

New versions of the validation service will be released with the WDTF release packages. The web site will provide access to the validator for various WDTF release versions. As we improve the validator's rule base we will make pre-WDTF release versions of the validator available for testing on the web site.

Use the web based validation service.

Validation service architecture