app.js

var express = require('express');
var topojson = require('topojson');
var fs = require('fs');
var child = require("child_process");

var port = process.env.PORT || 3000;
var app = express();
app.use(express.bodyParser());
app.set('json spaces',0);
app.use(express.compress());
app.use(express.methodOverride());
app.use('/', express.static(__dirname + '/static'));
app.listen(port);

app.get('/', function(req, res){
  res.sendfile(__dirname + '/index.html');
});

app.get('/map', function(req, res){
  res.sendfile(__dirname + '/map.html');
});

var topo_out = function( req, res, topology ){
  if(req.query && (req.query.doubledouble == "true" || req.query.doubleDouble == "true" || req.query.DoubleDouble == "true")){
    var endpt = topology.objects.collection.geometries.length;
    for(var i=0;i<endpt;i++){
      var newobj = {
        id: endpt + i + 1,
        type: topology.objects.collection.geometries[i].type + "",
        arcs: topology.objects.collection.geometries[i].arcs.concat( )
      };
      topology.objects.collection.geometries.push( newobj );
    }
  }
  if(req.query && (req.query.animalstyle == "true" || req.query.animalStyle == "true" || req.query.AnimalStyle == "true")){
    var animals = [ "olinguillo", "armadillo", "zebra", "chimpanzee", "dragon", "tiger", "lion", "squirrel", "dog", "frog", "shark", "tortoise", "giraffe", "parrot", "ant", "aphid", "spider", "crab", "tuna" ];
    for(var i=0;i<topology.objects.collection.geometries.length;i++){
      topology.objects.collection.geometries[i].id = animals[ Math.floor(Math.random() * animals.length) ] + topology.objects.collection.geometries[i].id;
    }
  }
  return res.json( topology );
};

var keepProps = function(properties, key, value) {
  properties[key] = value;
  return true;
};

app.post('/', function(req, res){
  // check for POSTed files through web interface
  var fileCount = 0;
  for(var file in req.files){
    fileCount++;
    fs.readFile(req.files[file].path, function(error, file){
      var topology = topojson.topology({ collection: JSON.parse( file ) }, { "property-transform": keepProps });
      return topo_out( req, res, topology );
    });
    break;
  }
  if(fileCount == 0){
    // check for POSTed GeoJSON directly in body
    if(req.body && req.body.type && (req.body.geometry || req.body.coordinates || req.body.features)){
      if(req.body.features){
        var topology = topojson.topology({ collection: JSON.parse( req.body ) }, { "property-transform": keepProps });
        return topo_out( req, res, topology );
      }
      else{
        return res.json( req.body );
      }
    }
    else{
      // check each POSTed variable for GeoJSON
      var varCount = 0;
      for(var bodyvar in req.body){
        varCount++;
        var topology = topojson.topology({ collection: JSON.parse( req.body[bodyvar] ) }, { "property-transform": keepProps });
        return topo_out( req, res, topology );
      }
      if(varCount == 0){
        res.send('no GeoJSON?');
      }
    }
  }
});