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how to parse RDF/XML using rdflib.js or rdf-parser-rdfxml in Node.js


I am trying to read an rdf/xml file and parse it possibly in JSON or JavaScript Object or any other format. I try to search a lot of node libraries but couldn't find any good example to do so. All the have provide some API without proper documentation( Or they gave but I didn't understand properly). Here is something I have tried.

var fs = require('fs'),
rdfParser = require('rdf-parser-rdfxml');

var res=rdfParser(__dirname+'/1.xml');
console.log(res);

here is 1.xml file

<rdf:RDF
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:oneM2M="http://www.onem2m.org/ontology/Base_Ontology#"
    xmlns:owl="http://www.w3.org/2002/07/owl#"
    xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
    xmlns:cfso="http://203.254.173.81:8080/ontologies/ConnectedFarmServiceOntology.owl#"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema#">
  <oneM2M:Thing rdf:about="http://203.254.173.81:8080/ontologies/ConnectedFarmServiceOntology.owl#KETICF">
    <cfso:hasSpecies>
      <cfso:Species rdf:about="http://203.254.173.81:8080/ontologies/ConnectedFarmServiceOntology.owl#Type1"/>
    </cfso:hasSpecies>
    <cfso:hasSPName>
      <cfso:SPName rdf:about="http://203.254.173.81:8080/ontologies/ConnectedFarmServiceOntology.owl#Maxfor"/>
    </cfso:hasSPName>
    <cfso:hasLocation>
      <cfso:Location rdf:about="http://203.254.173.81:8080/ontologies/ConnectedFarmServiceOntology.owl#Buyeo"/>
    </cfso:hasLocation>
    <cfso:hasCropName>
      <cfso:CropName rdf:about="http://203.254.173.81:8080/ontologies/ConnectedFarmServiceOntology.owl#CharryTomato">
        <cfso:hasSpecies rdf:resource="http://203.254.173.81:8080/ontologies/ConnectedFarmServiceOntology.owl#Type1"/>
      </cfso:CropName>
    </cfso:hasCropName>
    <cfso:hasControlMode>
      <cfso:ControlMode rdf:about="http://203.254.173.81:8080/ontologies/ConnectedFarmServiceOntology.owl#A"/>
    </cfso:hasControlMode>
  </oneM2M:Thing>
</rdf:RDF>

I have also tried with rdflib.js in pretty much similar way.

var fs = require('fs'),
    $rdf = require('rdflib');

//var parser = new xml2js.Parser();
fs.readFile(__dirname + '/1.xml', function(err, data) {
    // Fetch data via a regular AJAX call, load from a file, or pass in a literal
    // string. In this example, it was loaded from 'https://fred.me/profile'
    var store = $rdf.graph()  // Init a new empty graph
    var contentType = 'application/rdf+xml'
    var baseUrl = ""
    var parsedGraph = $rdf.parse(data, store, baseUrl, contentType);

    $rdf.parse(data,function(triples){
        for (var i in triples){
            console.log(triples[i]);
        }
    })
});

Help me out someone :) Thanx in advance


Solution

  • I have found fs.readFile returns Object instead of String. So modified Source is Here:

    var fs = require("fs");
    var $rdf = require("rdflib");
    
    var rdfData = fs.readFileSync(__dirname + "/1.xml").toString();
    
    var store = $rdf.graph();
    var contentType = "application/rdf+xml";
    var baseUrl = "http://IoFTriples.com";
    try {
      $rdf.parse(rdfData, store, baseUrl, contentType);
    
      var stms = store.statementsMatching(undefined, undefined, undefined);
      for (var i = 0; i < stms.length; i++) {
        var stm = stms[i];
        console.log(stm); // the WebID of a friend
      }
    } catch (err) {
      console.log(err);
    }