rmlio/example2rml

example2RML

This JavaScript library generates a RML mapping based on data sources and corresponding RDF triples. It is available as a Node.js module.

Example

Consider the following table which we want to map to RDF.

id	firstname	lastname
0	john	doe
1	james	doe
2	Winston	Peterson

Let's have a look at the first row. The corresponding RDF triples we would want, look like this:

<http://www.example.com/0> a foaf:Person;
  foaf:firstName 'john';
  foaf:familyName 'Doe'.

Using this library, an RML mapping can be generated by providing both the data source and the example RDF triples. The RML mapping will look something like this.

<#Mapping>
  rr:subjectMap [
    rr:class foaf:Person
  ];
  
  rr:predicateObjectMap [
    rr:predicate foaf:firstName;
    rr:objectMap [
      rml:reference 'firstname'
    ]
  ];
  
  rr:predicateObjectMap [
    rr:predicate foaf:familyName;
    rr:objectMap [
      rml:reference 'lastname'
    ]
  ].

Usage

Node.js

Install the module via npm install example2rml. Below you can find an example on how to use the module.

let example2rml = require('example2rml');

let triples = [{
  subject: 'http://www.example.com/pieter',
  predicate: 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type',
  object: 'http://www.example.com#Person'
}, {
  subject: 'http://www.example.com/pieter',
  predicate: 'http://www.example.com#firstName',
  object: '"Pieter"'
}, {
  subject: 'http://www.example.com/pieter',
  predicate: 'http://www.example.com#lastName',
  object: '"Heyvaert"'
}, {
  subject: 'http://www.example.com/pieter',
  predicate: 'http://www.example.com#age',
  object: '"26"'
}];

let dataSources = [{
  type: 'csv',
  row: [{
    column: 'firstname',
    value: 'Pieter'
  },{
    column: 'lastname',
    value: 'Heyvaert'
  },{
    column: 'age',
    value: '26'
  }]
}];

example2rml(triples, dataSources).then(console.log);

Command Line Interface

Install the module via npm install -g example2rml. You execute an example via example2rml -i ./demo/1/data.csv -t ./demo/1/example2rml.nt, where -i is a comma separated list of paths to input data sources and -t is the path to the example triples. More information and other options can be found via example2rml -h.

Supported Data Formats

At the moment CSV and JSON are supported.

Copyright

The example2rml library is written by Pieter Heyvaert.

This code is copyrighted by Ghent University – imec.