create an sqlite rtree spatial index using node-sqlite3 and node-mapnik

create_index.js

/*

wget http://dl.dropbox.com/u/342088/10m-us-parks-area.sqlite

ogr2ogr -f SQLite parks.sqlite ParkPly_900913.shp

dane$ ogr2ogr -f SQLite parks.sqlite ~/Documents/MapBox/cache/2976a0c1-10m-us-parks-area/2976a0c1-10m-us-parks-area.shp

*/

var mapnik = require('./lib/mapnik');
var sqlite3 = require('sqlite3');

/*var options = {
    type: 'sqlite',
    file: '10m-us-parks-area.sqlite',
    table: '"10m_us_parks_area"'
    //extent: '-20037508.34,-20037508.34,20037508.34,20037508.34'
};
*/

var options = {
    type: 'sqlite',
    file: 'parks.sqlite',
    table: '"2976a0c1_10m_us_parks_area"',
    extent: '-20037508.34,-20037508.34,20037508.34,20037508.34',
    use_spatial_index:false
};


var db = new sqlite3.Database(options.file);

var table = options.table.slice(1,-1);
var geom_col = 'GEOMETRY';

//db.run("drop virtual table \"" + table + "_" + geom_col + "\"");
var spatial_index_sql = "create virtual table idx_" + table + "_" + geom_col + " using rtree(pkid, xmin, xmax, ymin, ymax)";

var extent_insert = "insert into idx_" + table +  "_"  +  geom_col + " values (?,?,?,?,?)";

db.serialize(function() {

  db.run(spatial_index_sql);
  
  var stmt = db.prepare(extent_insert);

  var ds = new mapnik.Datasource(options);
  
  // get one feature
  var featureset = ds.featureset();

  var feature;
  while (feature = featureset.next()) {
      var e = feature.extent();
      stmt.run(feature.id(),e[0],e[1],e[2],e[3]);
  }

  stmt.finalize();

});

db.close();