How to process an uploaded KML file in GeoDjango

Question

I wrote a cmd line routine to import a kml file into a geoDjango application, which works fine when you feed it a locally saved KML file path (using the datasource object).

Now I am writing a web file upload dialog, to achieve the same thing. This is the beginning of the code that I have, problem is, that the GDAL DataSource object does not seem to understand Djangos UploadedFile format. It is held in memory and not a file path as expected.

What would be the best strategy to convert the UploadedFile to a normal file, and access this through a path? I dont want to keep the file after processing.

def createFeatureSet(request):
if request.method == 'POST':
    inMemoryFile = request.FILES['myfile']
    name = inMemoryFile.name
    POSTGIS_SRID = 900913
    ds = DataSource(inMemoryFile) #This line doesnt work!!! 
    for layer in ds:
        if layer.geom_type in (OGRGeomType('Point'), OGRGeomType('Point25D'), OGRGeomType('MultiPoint'), OGRGeomType('MultiPoint25D')):
            layerGeomType = OGRGeomType('MultiPoint').django
        elif layer.geom_type in (OGRGeomType('LineString'),OGRGeomType('LineString25D'), OGRGeomType('MultiLineString'), OGRGeomType('MultiLineString25D')):
            layerGeomType = OGRGeomType('MultiLineString').django
        elif layer.geom_type in (OGRGeomType('Polygon'), OGRGeomType('Polygon25D'), OGRGeomType('MultiPolygon'), OGRGeomType('MultiPolygon25D')):
             layerGeomType = OGRGeomType('MultiPolygon').django

Answer 1

Here is a suggested solution using a tempfile. I put the processing code in its own function which is now called.

    f = request.FILES['myfile']
    temp = tempfile.NamedTemporaryFile(delete=False)
    temp.write(f.read())
    temp.close()
    createFeatureSet(temp.name, source_SRID= 900913)

Answer 2

DataSource is a wrapper around GDAL's C API and needs an actual file. You'll need to write your upload somewhere on the disk, for insance using a tempfile. Then you can pass the file to DataSource.