A bug with the SparqlXmlWriter was reported this morning. It relates to the production of malformed SPARQL XML Results when you have a SparqlResultSet for which some variables are bound to null. This has been already been fixed in SVN as of revision 1439

If you are not willing/able to use potentially unstable builds from SVN then this workaround may be usable in some situations. If you are are generating SPARQL Results where you can control how they are serialized then you can call Trim() on the results prior to serializing them, the method eliminates all null values from the Result Set so the writer will then produce valid SPARQL XML Results as it won't erroneously try and serialize the null value.

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The latest version of our Tools package for Windows has now been released. This consists of an assortment of command line and GUI tools designed to help windows users work with RDF on a daily basis.

You can get this by going to Download dotNetRDF Toolkit for Windows.

All tools are built against our latest core library release. Even if a tool you use hasn't received any updates directly please upgrade to this version to get the benefits of performance improvements and bug fixes in the core library.

New Features and Improvements in this release include:

• rdfEditor
  • Basic Print Functionality
  • Find and Replace, Go To Line and other editing improvements
  • Double-click to select symbols
• soh
  • Command line utility for making all forms of SPARQL requests over HTTP
• SparqlGUI
  • Added in application viewing of Query Results
  • Better formatting of queries in the Query Inspector
• Store Manager
  • Recent and Favourite Connections feature
  • Added support for Fuseki servers
  • Improved SPARQL Query Results viewing
  • Force any connection to be read-only

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The latest version of dotNetRDF is now available. This is a major release which adds many new features but has also focused on a lot of internal restructuring and rewriting to improve performance and extensibility. Official build number for this release is 0.4.023346

The list of bug fixes and improvements goes far beyond what we've listed here (see the Change Log in the downloads for full details) but these are some of the major new features/improvements in this release:

Graph Improvements

You can now use the new Difference(IGraph g) method to calculate the differences between an RDF Graph and another Graph. This returns a GraphDiffReport detailing the differences.

You can also now use the ToDataTable() method to generate a DataTable from any IGraph instance.

In addition we've added new extension methods to make loading data even quicker and save you a using VDS.RDF.Parsing; declaration:

Graph g = new Graph();
g.LoadFromFile("example.rdf");

Parsing Improvements

{ ?type rdfs:subClassOf ?supertype . ?x a ?type } => { ?x a ?supertype }

Serialisation Improvements

Added a HtmlSchemaWriter which can be used to generate a human readable vocabulary specification style document from an RDF Graph - see the Configuration Vocabulary for an example of this (note that if your Accept header specifies RDF formats before HTML you'll get the RDF instead)

Added a new IQueryFormatter interface for formatting queries. Implemented it for SparqlFormatter to provide much better formatted output of parsed queries.

Query and Update Improvements

We've been working hard to make our SPARQL implementation as close to the latest editors drafts for SPARQL 1.1 as possible. This has included adding support for a wide array of newly defined SPARQL built-in functions, fixes to our Query Evaluation logic and support for new SPARQL Update commands like ADD.

Our implementation - Leviathan - now passes the entire SPARQL 1.0 test suite (bar 3 normalisation tests due to a .Net limitation) and the vast majority of the SPARQL 1.1 test suite (see Known Issues for more details on what we don't support). SPARQL Support in dotNetRDF should now be more accurate and more efficient then ever before.

Note that syntax for query is now set to SPARQL 1.1 standard by default.

Storage Improvements

Support for Fuseki has been added in this release. In addition 4store support has been updated so that triple level updates are now enabled by default (i.e. INSERT/DELETE DATA support).

We have also improved our SparqlHttpProtocolConnector to conform to the latest specifications for the SPARQL Uniform HTTP Protocol (soon to be renamed to SPARQL RDF Dataset HTTP Protocol).

ASP.Net Integration Improvements

All Handlers now output CORS headers that allow Javascript clients to access their services and data (can be disabled if desired). All SPARQL handlers now serve Service Description documents in response to appropriate requests.

Downloads

To get it just Download dotNetRDF or Download dotNetRDF Source if you want to build it yourself.

Tags: 0.4.0, 040, Beta, dotNetRDF, Features, Improvements, New, Releases

dotNetRDF has featured in it's first CodeProject article title Ontology, Notation 3, and SPARQL.

While the article is primarily an introduction to some of the core ideas behind the Semantic Web it includes practical examples all written using dotNetRDF.

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