EasyRdf

EasyRdf is a PHP library designed to make it easy to consume and produce RDF. It was designed for use in mixed teams of experienced and inexperienced RDF developers. It is written in Object Oriented PHP and has been tested extensively using PHPUnit.

After parsing EasyRdf builds up a graph of PHP objects that can then be walked around to get the data to be placed on the page. Dump methods are available to inspect what data is available during development.

Data is typically loaded into an [EasyRdf\Graph] object from source RDF documents, loaded from the web via HTTP. The [EasyRdf\GraphStore] class simplifies loading and saving data to a SPARQL 1.1 Graph Store.

SPARQL queries can be made over HTTP to a Triplestore using the [EasyRdf\Sparql\Client] class. SELECT and ASK queries will return an [EasyRdf\Sparql\Result] object and CONSTRUCT and DESCRIBE queries will return an [EasyRdf\Graph] object.

Example

$foaf = new \EasyRdf\Graph("http://njh.me/foaf.rdf");
$foaf->load();
$me = $foaf->primaryTopic();
echo "My name is: ".$me->get('foaf:name')."\n";

Downloads

The latest stable version of EasyRdf can be downloaded from the EasyRdf website.

Links

• EasyRdf Homepage
• API documentation
• Change Log
• Source Code
• Issue Tracker

Requirements

• PHP 7.1 or higher

Features

• API documentation written in phpdoc
• Extensive unit tests written using phpunit
• Built-in parsers and serialisers: RDF/JSON, N-Triples, RDF/XML, Turtle
• Optional parsing support for: ARC2, rapper
• Optional support for [Zend\Http\Client]
• No required external dependencies upon other libraries (PEAR, Zend, etc...)
• Complies with Zend Framework coding style.
• Type mapper - resources of type foaf:Person can be mapped into PHP object of class Foaf_Person
• Support for visualisation of graphs using GraphViz
• Comes with a number of examples

List of Examples

• basic.php - Basic "Hello World" type example
• basic_sparql.php - Example of making a SPARQL SELECT query
• converter.php - Convert RDF from one format to another
• dump.php - Display the contents of a graph
• foafinfo.php - Display the basic information in a FOAF document
• foafmaker.php - Construct a FOAF document with a choice of serialisations
• graph_direct.php - Example of using EasyRdf\Graph directly without EasyRdf\Resource
• graphstore.php - Store and retrieve data from a SPARQL 1.1 Graph Store
• graphviz.php - GraphViz rendering example
• html_tag_helpers.php - Rails Style html tag helpers to make the EasyRdf examples simpler
• httpget.php - No RDF, just test EasyRdf\Http\Client
• open_graph_protocol.php - Extract Open Graph Protocol metadata from a webpage
• serialise.php - Basic serialisation example
• sparql_queryform.php - Form to submit SPARQL queries and display the result
• uk_postcode.php - Example of resolving UK postcodes using uk-postcodes.com
• wikidata_villages.php - Fetch and information about villages in Fife from Wikidata
• zend_framework.php - Example of using Zend\Http\Client with EasyRdf

Contributing

We welcome any contributions. For further information please read CONTRIBUTING.md.

For further information about extending / hack EasyRdf please read DEVELOPER.md.

Running Examples

The easiest way of trying out some of the examples is to use the PHP command to run a local web server on your computer.

php -S localhost:8080 -t examples

Then open the following URL in your browser: http://localhost:8080/

Licensing

The EasyRdf library and tests are licensed under the BSD-3-Clause license. The examples are in the public domain, for more information see UNLICENSE.