tile.js

var url = require('url');

module.exports.parseXYZ = function(req, TMS_SCHEME, callback) {

    var matches = req.url.match(/(\d+)/g);
    if (matches && matches.length == 3) {
        try {
            var x = parseInt(matches[1], 10);
            var y = parseInt(matches[2], 10);
            var z = parseInt(matches[0], 10);
            if (TMS_SCHEME)
                y = (Math.pow(2, z) - 1) - y;
            callback(null,
               { z: z,
                 x: x,
                 y: y
               });
        } catch (err) {
            callback(err, null);
        }
    } else {
          try {
              var query = url.parse(req.url, true).query;
              if (query &&
                  query.x !== undefined &&
                  query.y !== undefined &&
                  query.z !== undefined) {
                  try {
                      callback(null,
                          { z: parseInt(query.z, 10),
                          x: parseInt(query.x, 10),
                          y: parseInt(query.y, 10)
                          }
                      );
                  } catch (err) {
                      callback(err, null);
                  }
              } else {
                  callback(new Error('no x,y,z provided'), null);
              }
          } catch (err) {
              callback(err, null);
          }
    }
};