app.js

// Imports
// Imports
var { QueryFactory, QueryRepository } = require("./model/model");
var express = require('express');
var bodyParser = require("body-parser");
const fetch = require("node-fetch");


// Config
var port = process.env.PORT || 3020;
var app = express();
app.use(express.json())
app.use(bodyParser.urlencoded({ extended: false }));
app.use(function (req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    next();
});

// Define SPARQL endpoint, TODO: Make dynamic
const endpointUrl = 'https://query.wikidata.org/sparql';


// runQuery : Takes sparqlQueryObject as input and populates sparqlQueryObject.queryResult
runQuery = sparqlQueryObject => {
    endpoint = endpointUrl;
    const fullUrl = endpoint + '?query=' + encodeURIComponent(sparqlQueryObject.queryString);
    const headers = { 'Accept': 'application/sparql-results+json' };

    return fetch(fullUrl, { headers })
        .then(body => body.json())
        .then(result => {
            sparqlQueryObject.setResult(result);
            return sparqlQueryObject
        });
}


// Initialize query factory
var queryFactory = new QueryFactory();


// REST API: Handle incoming POST request
app.post("/runQuery", (request, response) => {
    let queryObject = queryFactory.createQueryObject(request.body.query, null);
    runQuery(queryObject)
        .then(queryObject => response.send(queryObject.queryResult.results.bindings))
})

app.get("/", (request, response) => {
    response.send("SPARQL-service is running");
})

// Start listening
app.listen(port, function () {
    console.log(`SPARQL Query microservice listening on port`, port);
});
// var { QueryFactory, QueryRepository  } = require("./model/model");
// var express = require('express');
// var bodyParser = require("body-parser");
// const fetch = require("node-fetch");


// // Config
// var port = process.env.PORT || 3020;
// var app = express();
// app.use(express.json())
// app.use(bodyParser.urlencoded({ extended: false }));
// app.use(function(req, res, next) {
//     res.header("Access-Control-Allow-Origin", "*");
//     res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
//     next();
//   });

// // Define SPARQL endpoint, TODO: Make dynamic
// const endpointUrl = 'https://query.wikidata.org/sparql';


// // runQuery : Takes sparqlQueryObject as input and populates sparqlQueryObject.queryResult
// runQuery = sparqlQueryObject => {
//     endpoint = endpointUrl;
//     const fullUrl = endpoint + '?' +  encodeURIComponent(sparqlQueryObject.queryString);
//     const headers = { 'Accept': 'application/sparql-results+json' };

//     return fetch( fullUrl, { headers } )
//         .then( body => body.json())
//         .then( result => {
//             sparqlQueryObject.setResult(result);
//             return sparqlQueryObject
//         });
// }


// // Initialize query factory
// var queryFactory = new QueryFactory();


// // REST API: Handle incoming POST request
// app.post("/runQuery", (request, response) => {
//     console.log("fetching response")
//     let queryObject = queryFactory.createQueryObject(request.body.query, null);
//     runQuery(queryObject)
//     .then(queryObject => response.send(queryObject.queryResult.results.bindings))
// })

// app.get("/", (request, response) => {
//     response.send("SPARQL-service is running");
// })

// // Start listening
// app.listen(port, function () {
//     console.log(`SPARQL Query microservice listening on port`, port);
// });