Tiles serialization in base64 using django and landez

gistfile1.py

import base64
from StringIO import StringIO

from django.http import HttpResponse
from django.utils import simplejson

from easydict import EasyDict as edict
from landez import TilesManager

from . import app_settings


def tiles_serialize(request):
    result = edict(dict(bbox=[-0.56, 44.84, -0.55, 44.85],
                        zoomlevels=range(17, 19),
                        mimetype='image/png',
                        tiles=[]))
    
    # Take tiles from a TMS
    tm = TilesManager(tiles_url=app_settings.TILES_URL)
    # ... change it to : mb = TilesManager(mbtiles_file="yourfile.mbtiles") 
    #     to take tiles from a MBtiles !
    tiles = tm.tileslist(result.bbox, result.zoomlevels)
    for tile in tiles:
        tm.prepare_tile(tile)  # download, extract or take from cache
        tile_path = tm.tile_fullpath(tile)
        # Encode PNG in base64
        output = StringIO()
        with open(tile_path) as f:
            base64.encode(f, output)
        encoded = ''.join(output.getvalue().splitlines())
        output.close()
        # Add the encoded tile to the list
        result.tiles.append(dict(tile=tile,
                                 data=encoded))

    # Django specific code to serve the tiles list in JSON
    response = HttpResponse(mimetype='application/json')
    simplejson.dump(result, response, ensure_ascii=False, separators=(',',':'))
    return response