Routeboxer server side

Question

I'm trying to find out a way to get latitude and longitude bounds from google's routeboxer to php and then query mysql by those limits. I'll then output the results to json or xml to use those with android maps api v2. I found this http://luktek.com/Blog/2011-02-03-google-maps-routeboxer-in-php , but I think that this only does boxes between two points on a map, not boxes around the route itself which makes it not accurate enough. Using javascript is not an option, since I can't use it with google maps api or get the results from my database. Is there any way to accomplish this by using some server side code (preferably PHP, but any other language that works with mysql can be used as well), that can fetch the bounds, query mysql by those and output the data to json or xml so that it can be parsed by android?

Answer 1

I finally found a solution that I'm satisfied with. I'm not going to paste every step because it's going to take like thousand lines but here's it in a nutshell:
1. Parse this field from Google directions api json(https://developers.google.com/maps/documentation/directions/#JSON): "overview_polyline": {
2. Decode the polyline to latitude and longitude points with this: http://unitstep.net/blog/2008/08/02/decoding-google-maps-encoded-polylines-using-php/
3. Download this https://github.com/bazo/route-boxer. I piled all the code from GeoTools php-files to a one file but that's not propably necessary if you'll know how to use that :)
4. And here is an example of getting those boxes using those scripts:

...

$from = "(Startup point for example: "Turku,Finland")";
$to = "(Destination point fro example: "Porvoo,Finland")";

$json_string = file_get_contents("http://maps.googleapis.com/maps/api/directions/json?origin=$from&destination=$to&sensor=false");
$parsed_json = json_decode($json_string, true);

$polyline = $parsed_json['routes'][0]['overview_polyline']['points'];

$routepoints = decodePolylineToArray($polyline);

$collection = new LatLngCollection($routepoints);

$boxer = new RouteBoxer();

//calculate boxes with 10km distance from the line between points
$boxes = $boxer->box($collection, $distance = 10);

foreach($boxes as $row){

$southWestLtd = $row->southWest->latitude;
$southWestLng = $row->southWest->longitude;
$northEastLtd = $row->northEast->latitude;
$northEastLng = $row->northEast->longitude;

$query = "SELECT * FROM markers WHERE Latitude > $southWestLtd AND Latitude < $northEastLtd AND Longitude > $southEastLng AND Longitude < $norhtEastLng";

}

Run that query and it'll give you only the markers (or what ever you are querying) that are inside those boxes. If you'll need some more detailed instructions just leave a comment. I'm more than happy to help since I spent many nights trying to find a reasonable solution to this.

Answer 2

Lots of questions here, let me try to tackle some: Getting lat and long bounds from routeboxer: Once you have your 'boxes', you can loop through and get these

var northeast = boxes[i].getNorthEast();
var southwest = boxes[i].getSouthWest();
var lat_north = northeast.lat();
var long_east = northeast.lng();

var lat_south = southwest.lat();
var long_west = southwest.lng();

> at this only does boxes between two points on a map, not boxes around the route itself which makes it not accurate enough

I do not know about this persons implementation of Routeboxer but the original Google Routeboxer for the API v3 creates boxes around the entire route. That is what is documented and I can say with confidence, how it works (I've used it) http://google-maps-utility-library-v3.googlecode.com/svn/trunk/routeboxer/docs/examples.html

> Using javascript is not an option, since I can't use it with google maps api or get the results from my database.

This point makes little sense to me. You DEFINITELY CAN use Google Maps API with Javascript, there is a Javascript Library (version 3 already) specifically FOR THIS PURPOSE. If this is a browser application I would strongly recommend sticking with that, at least initially.

As for getting results from DB, you can use AJAX calls (basically just call your php script via AJAX, have it return JSON data, then use JAVASCRIPT to parse/populate this data onto the screen of the user... Alternately, it doesn't even have to be ajax, you can use routeboxer, then upon some action, submit this to your DB, then have the next page return with results rendered... But AJAX really is the more elegant approach (this case is almost an 'ideal use-case' for it)

BTW: I do not see the logic of putting Routerbox 'server-side' as this programmer has done. He points out rightly to the fact that very long, complex routes, will take time but my thoughts would be: "whether the user is waiting for his PC to crunch the data, or he is waiting for a remote PC (the server) to crunch the data....... all he knows and cares about is that he is waiting, NOT THE BACKEND METHODOLOGY! (with the exception being when one has access to a series of powerful servers and can rewrite the server-side code to take advantage of parallel-runs etc...)