kmlfilter.py

import sys, os
import optparse
import glob
import json
import time
import zipfile
import kmlengine
import kmldom
from kmlengine import Bbox

DEFAULT_SECTOR_JSONFILE = "sectors.json"

def create_zipfile(outZip, files, delete_after=True):
    zfile = zipfile.Zipfile(outZip)
    try:
        for file in files:
            zfile.write(file)
    finally:
        zfile.close()
    for file in files:
        os.unlink(file)

def bbox_for_sector(sector, sectorfile=options.sector_file):
    sectors = json.loads(open(sectorfile).read())
    props = sectors[sector]
    north, west, south, east = props['bounds']
    bbox = Bbox()
    bbox.ExpandLatLon(north, west)
    bbox.ExpandLatLon(south, east)
    return bbox


class KmlFilter(object):
    def __init__(self, bbox=None):
        self.bbox = bbox
    
    def handleKmlFile(self, url, isTopLevel=False):
        print 'processing:', url
        self.urlStack.append(url)
        tmpPath = self.getLocalPath(url)
        
        # Parse with libkml
        # walk the dom for features
        # compare each feature's bbox to the filter bbox and accept or reject
        # if the feature is a NetworkLink (and is not rejected), recurse on it

        if isTopLevel:
            outPath = '%s/%s' % (self.outDir, 'doc.kml')
        else:
            (fd, outPath) = tempfile.mkstemp('-KmlSnapshot')
            os.close(fd)
            SysUtil.chmodIfPossible(outPath, 0777)
        file(outPath, 'w').write(outStr.encode('utf-8'))
        self.urlStack.pop()
        return outPath

    def spiderKmlFile(self, inUrl, outDir):
        SysUtil.mkdirP(outDir)
        self.outDir = outDir
        self.handleKmlFile(inUrl, True)

    def start_filter(self, inUrl, outZip=None):
        if not outZip:
            timestamp = time.strftime('%Y-%m-%d-%H%Mh')
            SysUtil.mkdirP('/tmp/kml')
            outZip = '/tmp/kml/filtered-%s.zip' % timestamp

        outZip = os.path.abspath(outZipRel)
        outZipBasename = os.path.basename(outZipRel)
        outZipNoExt, _ = os.path.splitext(outZipBasename)
        tempDir = '/tmp/tmpKmlSnapshot-%d-%d' % (os.getpid(), random.randint(0,9999))
        tempDirContents = os.path.join(tempDir, outZipNoExt)
        self.spiderKmlFile(inUrl, tempDirContents)
        oldDir = os.getcwd()
        os.chdir(tempDir)
        files = string.join(glob.glob('*'), ' ')
        create_zipfile(outZip, files)
        os.chdir(oldDir)

        return outZip

def start_filter(inurl, outzip=None):
    bbox = bbox_for_sector(options.sector)
    return KmlFilter(bbox).start_filter(inurl, outzip)

def main():
    parser = optparse.OptionParser()
    parser.add_option('--sector-file', dest=sector_filename, help="File containing JSON representation of the sectors to filter by.", default=DEFAULT_SECTOR_FILE)
    parser.add_option('--sector', dest=sector, help="Name of the sector to filter by.", default="OFUNTO")
    global options
    options, args = parser.parse_args()
    if len(args) > 2:
        print 'KmlSnapshot: expected no more than 2 positional arguments'
        parser.print_help()
        sys.exit(1)
    start_filter(*args)

if __name__ == "__main__":
    main():

sectors.json

{
    "KESENNUMA":
    {
        "maxZoom": 18,
        "minZoom": 2,
        "name": "KESENNUMA SECTOR",
        "bounds": [
            38.978549999999998,
            141.48361666666668,
            38.7759,
            141.73778333333334
        ]
    },


    "OFUNTO":
    {
        "maxZoom": 18,
        "minZoom": 2,
        "name": "OFUNATO SECTOR",
        "bounds": [
            39.174016666666667,
            141.66826333512131,
            38.985799999999998,
            141.7913534314379
        ]
    },


    "RIKUZENTAKATA":
    {
        "maxZoom": 18,
        "minZoom": 2,
        "name": "RIKUZENTAKATA SECTOR",
        "bounds": [
            39.178766666666668,
            141.38698333333335,
            38.985799999999998,
            141.71613333333335
        ]
    },


    "SOUTH_KAMAISHI":
    {
        "maxZoom": 18,
        "minZoom": 2,
        "name": "SOUTH KAMAISHI SECTOR",
        "bounds": [
            39.174016666666667,
            141.74863333333334,
            39.024416666666667,
            141.93601666666666
        ]
    }
}