def calculate(request, save_output=save_to_geonode):
start = datetime.datetime.now()
if request.method == 'GET':
# FIXME: Add a basic form here to be able to generate the POST request.
return HttpResponse('This should be accessed by robots, not humans.'
'In other words using HTTP POST instead of GET.')
elif request.method == 'POST':
data = request.POST
impact_function_name = data['impact_function']
hazard_server = data['hazard_server']
hazard_layer = data['hazard']
exposure_server = data['exposure_server']
exposure_layer = data['exposure']
requested_bbox = data['bbox']
keywords = data['keywords']
if request.user.is_anonymous():
theuser = get_valid_user()
else:
theuser = request.user
# Create entry in database
calculation = Calculation(user=theuser,
run_date=start,
hazard_server=hazard_server,
hazard_layer=hazard_layer,
exposure_server=exposure_server,
exposure_layer=exposure_layer,
impact_function=impact_function_name,
success=False)
# Wrap main computation loop in try except to catch and present
# messages and stack traces in the application
try:
# Get metadata
haz_metadata = get_metadata(hazard_server, hazard_layer)
exp_metadata = get_metadata(exposure_server, exposure_layer)
# Determine common resolution in case of raster layers
raster_resolution = get_common_resolution(haz_metadata, exp_metadata)
# Get reconciled bounding boxes
haz_bbox, exp_bbox, imp_bbox = get_bounding_boxes(haz_metadata,
exp_metadata,
requested_bbox)
# Record layers to download
download_layers = [(hazard_server, hazard_layer, haz_bbox),
(exposure_server, exposure_layer, exp_bbox)]
# Add linked layers if any FIXME: STILL TODO!
# Get selected impact function
impact_function = get_plugin(impact_function_name)
impact_function_source = inspect.getsource(impact_function)
# Record information calculation object and save it
calculation.impact_function_source = impact_function_source
calculation.bbox = bboxlist2string(imp_bbox)
calculation.save()
# Start computation
msg = 'Performing requested calculation'
logger.info(msg)
# Download selected layer objects
layers = []
for server, layer_name, bbox in download_layers:
msg = ('- Downloading layer %s from %s'
% (layer_name, server))
logger.info(msg)
L = download(server, layer_name, bbox, raster_resolution)
layers.append(L)
# Calculate result using specified impact function
msg = ('- Calculating impact using %s' % impact_function)
logger.info(msg)
impact_filename = calculate_impact(layers=layers,
impact_fcn=impact_function)
# Upload result to internal GeoServer
msg = ('- Uploading impact layer %s' % impact_filename)
logger.info(msg)
result = save_output(impact_filename,
title='output_%s' % start.isoformat(),
user=theuser)
except Exception, e:
# FIXME: Reimplement error saving for calculation.
# FIXME (Ole): Why should we reimplement?
# This is dangerous. Try to raise an exception
# e.g. in get_metadata_from_layer. Things will silently fail.
# See issue #170
logger.error(e)
errors = e.__str__()
trace = exception_format(e)
calculation.errors = errors
calculation.stacktrace = trace
calculation.save()
jsondata = json.dumps({'errors': errors, 'stacktrace': trace})
return HttpResponse(jsondata, mimetype='application/json')
