First crack at geoJSON output

TODO:  retrieve missing nodes referenced in ways to get their coords.

Author: mharnold

.gitignore

@@ -1,4 +1,8 @@
+*~
+*.swp
+.DS_Store
 *.pyc
-build
-dist
-overpass.egg-info
+
+/build/
+/dist/
+/*.egg-info

overpass/api.py

@@ -1,7 +1,8 @@
 import sys
 import requests
 import json
-from shapely.geometry import mapping, Point
+import geojson
+#from shapely.geometry import mapping, Point
 
 
 class API(object):
@@ -96,23 +97,62 @@ def _GetFromOverpass(self, query):
             return r.text
 
     def _asGeoJSON(self, elements):
-        """construct geoJSON from elements"""
+        """
+        Construct geoJSON from elements
+        TODO:  Add secondary overpass call to get coords for ways for nodes not included in elements.
+        """
+        node_elements_by_id = {}
+
+        # index node elements by id
+        for elem in elements:
+            if elem["type"] == "node": 
+                node_elements_by_id[elem["id"]] = elem
+
+        features = []
+        for elem in elements:
+            elem_type = elem["type"]
+            if elem["type"] == "node":
+                geometry=geojson.Point((elem["lon"], elem["lat"]))
+            elif elem["type"] == "way":
+                points = []
+                for node_id in elem["nodes"]:
+                    node_elem = node_elements_by_id.get(node_id)
+                    if node_elem:
+                        point = (node_elem["lon"], node_elem["lat"])
+                        points.append(point)
+                    else
+                        print 'WARNING _asGeoJson skipping missing node ref in way
+                geometry = geojson.LineString(points)
+            else:
+                continue
+
+            feature = geojson.Feature(
+                        id=elem["id"],
+                        geometry=geometry,
+                        properties=elem.get("tags"))
+            features.append(feature)
+
+        return geojson.FeatureCollection(features)
+
+'''
         nodes = [{
             "id": elem.get("id"),
-            "tags": elem.get("tags"),
+            "tags": elem.get("tags")
             "geom": Point(elem["lon"], elem["lat"])}
             for elem in elements if elem["type"] == "node"]
         ways = [{
             "id": elem.get("id"),
             "tags": elem.get("tags"),
             "nodes": elem.get("nodes")}
             for elem in elements if elem["type"] == "way"]
-        print nodes
-        print ways
+'''
+
+
+
 
 class OverpassException(Exception):
     def __init__(self, status_code, message):
         self.status_code = status_code
         self.message = message
     def __str__(self):
-        return json.dumps({'status': self.status_code, 'message': self.message})
+        return json.dumps({'status': self.status_code, 'message': self.message})

requirements.txt

@@ -11,5 +11,5 @@
     download_url='https://github.com/mvexel/overpass-api-python-wrapper/tarball/0.0.1',
     keywords=['openstreetmap', 'overpass', 'wrapper'],
     classifiers=[],
-    install_requires=['requests>=2.3.0', 'shapely>=1.4.3'],
+    install_requires=['requests>=2.3.0', 'geojson>=1.0.9'],
 )

setup.py

@@ -1,9 +1,26 @@
+import geojson
 import overpass
 
-
 class TestAPI:
 
     def test_initialize_api(self):
         api = overpass.API()
         assert isinstance(api, overpass.API)
-        assert api.debug == False
+        assert api.debug == False
+
+    def test_geojson(self):
+        api = overpass.API()
+        osm_elements = api.Get(overpass.MapQuery(37.86517,-122.31851,37.86687,-122.31635))
+        osm_geo  = api.Get(overpass.MapQuery(37.86517,-122.31851,37.86687,-122.31635), asGeoJSON=True)
+        #print 'DEB osm_elements:', geojson.dumps(osm_elements,sort_keys=True,indent=2)
+        print 'DEB osm_geo:', geojson.dumps(osm_geo,sort_keys=True,indent=2)
+        assert len(osm_geo['features']>1)
+
+    def run_tests():
+        self.test_initialize_api()
+        self.test_geojson()
+
+if __name__ == '__main__':
+    tapi = TestAPI()
+    tapi.test_geojson()
+    print "overpass PASS"