root/pleiades.keytree/trunk/keytree/factory.py

"""
Feature classes
"""

from keytree.model import Geometry, Feature
from keytree.model import GEOM_TYPES

def feature(element):
    kmlns = element.tag.split('}')[0][1:]
    kid = element.attrib.get('id')
    name = element.findtext('{%s}name' % kmlns)
    description = element.findtext('{%s}description' % kmlns)
    for geom_type in GEOM_TYPES:
        tag = '{%s}%s' % (kmlns, geom_type)
        geom_element = element.find(tag)
        if geom_element is not None:
            g = geometry(geom_element)
            return Feature(kid, g, name=name, description=description)
    return Feature(kid, None, name=name, description=description)

def geometry(element):
    tp = element.tag.split('}')
    kmlns = tp[0][1:]
    geom_type = tp[1]
    return geometry_factory[geom_type](element, kmlns)

def geometry_Point(element, kmlns):
    t = element.findtext('{%s}coordinates' % kmlns)
    tv = t.split(',')
    return Geometry('Point', tuple([float(v) for v in tv]))

def geometry_LineString(element, kmlns):
    text = element.findtext('{%s}coordinates' % kmlns)
    ts = text.split()
    coords = []
    for t in ts:
        tv = t.split(',')
        coords.append(tuple([float(v) for v in tv]))
    return Geometry('LineString', tuple(coords))

def geometry_Polygon(element, kmlns):
    shell = element.find('{%s}outerBoundaryIs' % kmlns)
    text = shell.findtext('*/{%s}coordinates' % kmlns)
    ts = text.split()
    shell_coords = []
    for t in ts:
        tv = t.split(',')
        shell_coords.append(tuple([float(v) for v in tv]))
    poly_coords = []
    poly_coords.append(tuple(shell_coords))

    holes = element.findall('{%s}innerBoundaryIs' % kmlns)
    for hole in holes:
        text = hole.findtext('*/{%s}coordinates' % kmlns)
        ts = text.split()
        hole_coords = []
        for t in ts:
            tv = t.split(',')
            hole_coords.append(tuple([float(v) for v in tv]))
        poly_coords.append(tuple(hole_coords))

    return Geometry('Polygon', tuple(poly_coords))

geometry_factory = {
    'Point': geometry_Point,
    'LineString': geometry_LineString,
    'Polygon': geometry_Polygon,
    }