VGR : Visual Graph Requestor

A graphical SPARQL interface

Overview

VGR is a windows application in the look-and-feel of Microsoft Office(c).

VGR offers the different layout to display graphs :

classical force directed or energy based layout (2 variants)
hierarchical layout (find the major tree). This layout is the best suited for tree (or forest) but could be used for all graphs,
orthogonal layout (very rare, a real avantage of VGR). This layout is the best readable but limited to small graphs (nodes<800),
classical circular layout,
3D layout.

Status

Download and installation

Download the executable (no dependencies) from http://opoirel.free.fr/strixDB/download.html , place the unzipped executable where you want.

VGR could use every SPARQL/Protocol compliant RDFstore (but specially designed for StrixDB RDF store).

Launch the executable. A prompt window will ask you for a RDFstore HTTP address... Give it and envoy !

History

2011-03-02 Initial release

Interface Introduction

The different components of the interface are :

Tabbed views (1) with graphs layout.
A ribbon bar in the look-and feel of Microsoft Office (2). Three bars are available :
- Home bar to change the layout and offers common actions;
- Exploration bar to navigate and explore the graph ;
- Style Bar to change colors, line styles, etc... of the layout.
the catalog panel (3) (similar to file tree in a Windows explorer). It is organized in :
- a catalog of all graphs available in the RDFstore,
- a catalog of SPARQL forms.
- a catalog of requests
- a catalog of layout styles.
- a catalog of all the Datalog rules set available in the RDFstore (StrixDB RDFstore specificity).
the request panel (4) used to edit SPARQL requests and instanciate SPARQL templates.
the floating minimap (5) to navigate inside the graph layout (1).

SPARQL forms

The idea behind SPARQL forms is to request the RDF store using a form instead of SPARQL queries.

An example is more telling that many explanations :

Suppose that you commonly want to request graphs with an object string literal constrained by a string matching (a regex) and with subject having some type. In SPARQL, you have to write the following request for each query :

CONSTRUCT {?subject ?predicate ?val}
FROM ...some graph...
WHERE {
    ?subject ?predicate ?val.
    ?subject a ...some type....
    FILTER ( regex(?val, ...some pattern... ))
}

We have to notice that :

such a simple request could be hard to build for a SPARQL rookie.
it could be cumbersome to write all the time quite the same SPARQL request, just changing the FROM url, the type and the string pattern.
this could be quite impossible to do for lots of end users.

VGR offers help to build and use the following form to make the requests :

We will show how to build the following