Tastypie returns string representation rather than valid array for reverse foreignkey lookup

问题

UPDATE: Is the dehydrate within the LocationResource to blame?

I have an usual situation where a reverse lookup via a foreignkey is returning a nested string representation of an array, rather than the array itself. [I discovered this while using tastypie with backbone.js and backbone.marionette.][1]

The strange thing is that this does NOT happen when doing a "forward" or normal lookup, even if there are nested arrays returned from fields.ForeignKey resources

For example:

Forward lookups:

[{"adult_price": "123", "child_price": "123", "currency": [{"abbrev": "USD", ... }] } ]
//--> notice that "currency" simply returns an array, without " "

Reverse lookups - "backwards" via a foreignkey

[{"id": "1", "name": "Venice", "resource_uri": "/api/v1/location/1/", 
"theTours": "[{'subtitle': ... ... }]" } ]
//--> notice that there is a set of quotes " " outside the array for "theTours".
//--> a string representation of the array

The following is the setup of the resources, and then the models.

TASTYPIE RESOURCES

class LocationResource(ModelResource):

    class Meta:
        queryset = Location.objects.all()
        resource_name = 'location'

    def dehydrate(self, bundle):
        bundle.data['theTours'] = Tours.objects.filter(location__name=bundle.obj.name).values()
        return bundle
        filtering = {
            'name' : ALL_WITH_RELATIONS,
        }

    def override_urls(self):
        return [
            url(r"^(?i)(?P<resource_name>%s)/(?P<name>[\w\d_.-]+)/$" % self._meta.resource_name, self.wrap_view('dispatch_detail'), name="api_dispatch_detail"),
        ]   


class CurrencyResource(ModelResource):

    class Meta:
        queryset = Currency.objects.all()
        resource_name = 'currency'          
        filtering = {
            'name' : ALL,
            'abbrev' : ALL,
        }               


class ToursResource(ModelResource):
    day = fields.ToManyField(DayOfWeekResource, 'day', full=True)
    location = fields.ForeignKey(LocationResource, 'location', full=True, related_name="theLocs")
    currency = fields.ToManyField(CurrencyResource, 'currency', full=True)

    class Meta:
        queryset = Tours.objects.all()
        resource_name = 'tours'
        limit = 100
        filtering = {
            'day' : ALL_WITH_RELATIONS,
            'location' : ALL_WITH_RELATIONS,
            'currency' : ALL_WITH_RELATIONS,
        }

    def override_urls(self):
        return [
            url(r"^(?i)(?P<resource_name>%s)/day/(?P<day__day_of_week>[\w\d_.-]+)/$" % self._meta.resource_name, self.wrap_view('dispatch_detail'), name="api_dispatch_detail"),
            url(r"^(?i)(?P<resource_name>%s)/location/(?P<location__name>[\w\d_.-]+)/$" % self._meta.resource_name, self.wrap_view('dispatch_list'), name="api_dispatch_list"),
        ]

DJANGO MODELS

class Tours(models.Model):

    location = models.ForeignKey('app.Location', related_name="theTours")
    name = models.CharField(max_length=500)
    currency = models.ManyToManyField('app.Currency')

    class Meta:
        verbose_name_plural = "Tours"   

    def __unicode__(self):
        return self.name



class Location(models.Model):

    name = models.CharField(max_length=50, unique=True)

    def __unicode__(self):
        return self.name


class Currency(models.Model):

    abbrev = models.CharField(max_length=5, unique=True)
    name = models.CharField(max_length=50, unique=True)
    symbol = models.CharField(max_length=5)

    class Meta:
        verbose_name_plural = "Currencies"  

    def __unicode__(self):
        return self.name

回答1:

Based on your model :

class Tours(models.Model):

    location = models.ForeignKey('app.Location', related_name="theTours")
    ....
    ....

class Location(models.Model):

    ....

You want to use reverse relation like:Location.theTours.all(), so you need to add this to LocationResource :

theTours = fields.ToManyField(ToursResource, 'theTours', full = True)

The first theTours can be anything you want, the second one should be the same to related_name.

No need dehydrate.

Final result :

class LocationResource(ModelResource):

    theTours = fields.ToManyField(ToursResource, 'theTours', full = True)

    class Meta:
        queryset = Location.objects.all()
        resource_name = 'location'

    def override_urls(self):
        return [
            url(r"^(?i)(?P<resource_name>%s)/(?P<name>[\w\d_.-]+)/$" % self._meta.resource_name, self.wrap_view('dispatch_detail'), name="api_dispatch_detail"),
        ]

来源：https://stackoverflow.com/questions/13640412/tastypie-returns-string-representation-rather-than-valid-array-for-reverse-forei

标签

django

rest

tastypie