I'm developing an Android application with backend developed using Tastypie and Django. I have a get request for which I want to optionally be able to retrieve the entire object (with complete related fields, rather than URIs). Below is part of the python code for the resource I'm talking about:
class RideResource(ModelResource):
user = fields.ForeignKey(UserResource, 'driver')
origin = fields.ForeignKey(NodeResource, 'origin', full=True)
destination = fields.ForeignKey(NodeResource, 'destination', full=True)
path = fields.ForeignKey(PathResource, 'path')
# if the request has full_path=1 then we perform a deep query, returning the entire path object, not just the URI
def dehydrate(self, bundle):
if bundle.request.GET.get('full_path') == "1":
self.path.full = True
else:
ride_path = bundle.obj.path
try:
bundle.data['path'] = _Helpers.serialise_path(ride_path)
except ObjectDoesNotExist:
bundle.data['path'] = []
return bundle
As you can see the RideResource has a foreign key pointing to PathResource. I'm using the dehydrate function to be able to inspect if the GET request has a parameter "full_path" set to 1. In that case I set programmatically the path variable to full=True
. Otherwise I simply return the path URI.
The thing is that the code seems to work only the second time the GET is performed. I've tested it hundreds of times and, when I perform my GET with full_path=1
, even tho it enters the if and sets self.path.full = True
, the first time it only returns the URI of the PathResource object. While, if I relaunch the exact same request a second time it works perfectly...
Any idea what's the problem?
EDIT AFTER SOLUTION FOUND THANKS TO @Tomasz Jakub Rup
I finally managed to get it working using the following code:
def full_dehydrate(self, bundle, for_list=False):
self.path.full = bundle.request.GET.get('full_path') == "1"
return super(RideResource, self).full_dehydrate(bundle, for_list)
def dehydrate(self, bundle):
if not bundle.request.GET.get('full_path') == "1":
try:
bundle.data['path'] = _Helpers.serialise_path(bundle.obj.path)
except ObjectDoesNotExist:
bundle.data['path'] = []
return bundle
dehydrate
is called after full_dehydrate
. Overwrite full_dehydrate
function.
def full_dehydrate(self, bundle, for_list=False):
self.path.full = bundle.request.GET.get('full_path') == "1"
return super(RideResource, self).full_dehydrate(bundle, for_list)