Create repro_json.py

Reproject th geojson polygon to the DEM coordinate system

app/models/repro_json.py

@@ -0,0 +1,35 @@
+import json
+from osgeo import osr 
+
+
+def spatialref(epsg_code):
+    spatialref = osr.SpatialReference()
+    spatialref.ImportFromEPSG(epsg_code)
+    return spatialref
+
+def spatialrefWQT(dataset):
+    spatialref = osr.SpatialReference()
+    spatialref.ImportFromWkt(dataset.GetProjectionRef())
+    return spatialref
+
+def reprojson(geojson, dataset):
+
+    crsin= spatialref(4326)
+    crsout = spatialrefWQT(dataset)
+
+    coordinate_transformation = osr.CoordinateTransformation(crsin, crsout)
+
+     # Define dictionary representation of output feature collection
+    fc_out = {"geometry":{"type":"Polygon","coordinates":[]}}
+
+    # Iterate through each feature of the feature collection
+    new_coords = []
+        # Project/transform coordinate pairs of each ring
+        # (iteration required in case geometry type is MultiPolygon, or there are holes)
+    for ring in geojson['geometry']['coordinates']:
+        coords=[(entry[0],entry[1]) for entry in ring]
+        for i in range(len(coords)):
+            x2, y2, z= coordinate_transformation.TransformPoint(coords[i][0], coords[i][1])
+            new_coords.append([x2, y2])
+    fc_out['geometry']['coordinates'] = [new_coords]
+    return fc_out