Convert Google Sankey chart data to D3.js Sankey data (nodeJS)

convert_google_to_d3.js

/**
 * Convert Google Sankey chart data to D3.js Sankey data (nodeJS)
 * Usage: node convert_google_to_d3.js in-file.json out-file.json
 *
 * Requires: lodash — npm install lodash
 */

'use strict';

var _ = require('lodash');
var fs = require('fs');

if (process.argv.length < 4) {
  console.log('Usage: node convert_google_to_d3.js in-file.json out-file.json');
  process.exit(1);
} else {
  var inFile = process.argv[2];
  var outFile = process.argv[3];
}


fs.readFile(inFile, function(err, data){
  var nodes = [],
      links = [];

  var inData = JSON.parse(data);

  inData.forEach(function(v) {
    var index1 = _.findIndex(nodes, {'name': v[0]});
    var index2 = _.findIndex(nodes, {'name': v[1]});

    if (index1 === -1) { // new node
      index1 = nodes.push({'name': v[0]}) - 1;
    }

    if (index2 === -1) { // new node
      index2 = nodes.push({'name': v[1]}) - 1;
    }

    links.push({'source': index1, 'target': index2, 'value': v[2]});
  });

  fs.writeFile(outFile, JSON.stringify({'nodes': nodes, 'links': links}), function(err){
    if (err) {
      console.log('Error writing file.');
      process.exit(1);
    } else {
      console.log('D3 Sankey data successfully written to: ' + outFile);
      process.exit(0);
    }
  });

});