Django 使用Tastypie创建相关资源

我想让tastypie创建一个UserProfileResource，作为我发布到UserResource的结果

models.py：

class UserProfile(models.Model):
    home_address = models.TextField()
    user = models.ForeignKey(User, unique=True)

资源.py

class UserProfileResource(ModelResource):
    home_address = fields.CharField(attribute='home_address')

    class Meta:
        queryset = UserProfile.objects.all()
        resource_name = 'profile'
        excludes = ['id']
        include_resource_uri = False


class UserResource(ModelResource):
    profile = fields.ToOneField(UserProfileResource, 'profile', full=True)
    class Meta:
        queryset = User.objects.all()
        resource_name = 'user'
        allowed_methods = ['get', 'post', 'delete', 'put']
        fields = ['username']
        filtering = {
                'username': ALL,
                }

curl命令：

curl -v -H "Content-Type: application/json" -X POST --data '{"username":"me", "password":"blahblah", "profile":{"home_address":"somewhere"}}' http://127.0.0.1:8000/api/user/

但我得到了：

 Django Version:   1.4
 Exception Type:   IntegrityError
 Exception Value:
 null value in column "user_id" violates not-null constraint

这似乎是一个鸡和蛋的场景。我需要用户id来创建UserProfileResource，我需要配置文件来创建UserResource。显然，我在做一些非常愚蠢的事情

外面有人能发光吗？ 非常感谢 约翰诺克

我按照巴勃罗的建议修改了我的代码

class UserProfileResource(StssRessource):
    home_address = fields.CharField(attribute='home_address')
    user = fields.ToOneField('resources.UserResource', attribute='user', related_name='profile')

    class Meta:
        queryset = UserProfile.objects.all()
        resource_name = 'profile'


class UserResource(ModelResource):
    profile = fields.ToOneField('resources.UserProfileResource', attribute='profile', related_name = 'user', full=True)
    class Meta:
        queryset = User.objects.all()
        resource_name = 'user'

但我得到：

 Django Version:   1.4
 Exception Type:   DoesNotExist

这与尝试访问ORM中的用户资源有关，但在创建相关的\u对象UserProfileResource时，该资源不存在。这是正确的。用户ORM只有在创建相关的\u对象之后才会创建

---

其他人看到了吗？？？

在我最终设法保存相关资源的两天后，问题是您必须指定关系的双方及其相关名称，在您的情况下，可能是这样的：

class UserProfileResource(ModelResource):
    home_address = fields.CharField(attribute='home_address')
    user = fields.ToOneField('path.to.api.UserResource', attribute='user', related_name='profile')
         #in my case it was a toManyField, I don't know if toOneField works here, you can try toManyField.

class UserResource(ModelResource):
    profile = fields.ToOneField(UserProfileResource, 'profile', related_name='user', full=True)

EDIT#2:终于找到了解决问题的方法，但不幸的是，它需要一些子类化和重写。下面是我如何让它工作的：

首先，创建一个新的field子类-我将其称为my RelatedToOneField：

from tastypie.bundle import Bundle
from django.core.exceptions import ObjectDoesNotExist, MultipleObjectsReturned
from tastypie.exceptions import ApiFieldError, NotFound
class RelatedToOneField(fields.RelatedField):
    """
    Provides access to related data via foreign key.

    This subclass requires Django's ORM layer to work properly.
    """
    help_text = 'A single related resource. Can be either a URI or set of nested resource data.'

    def __init__(self, to, attribute, related_name=None, default=fields.NOT_PROVIDED,
                 null=False, blank=False, readonly=False, full=False,
                 unique=False, help_text=None):
        super(RelatedToOneField, self).__init__(
            to, attribute, related_name=related_name, default=default,
            null=null, blank=blank, readonly=readonly, full=full,
            unique=unique, help_text=help_text
        )
        self.fk_resource = None

    def dehydrate(self, bundle):
        try:
            foreign_obj = getattr(bundle.obj, self.attribute)
        except ObjectDoesNotExist:
            foreign_obj = None

        if not foreign_obj:
            if not self.null:
                raise ApiFieldError("The model '%r' has an empty attribute '%s' and doesn't allow a null value." % (bundle.obj, self.attribute))

            return None

        self.fk_resource = self.get_related_resource(foreign_obj)
        fk_bundle = Bundle(obj=foreign_obj, request=bundle.request)
        return self.dehydrate_related(fk_bundle, self.fk_resource)

    def hydrate(self, bundle):
        value = super(RelatedToOneField, self).hydrate(bundle)

        if value is None:
            return value
        # START OF MODIFIED CONTENT
        kwargs = {
            'request': bundle.request,
        }

        if self.related_name:
            kwargs['related_obj'] = bundle.obj
            kwargs['related_name'] = self.related_name

        return self.build_related_resource(value, **kwargs)
        #return self.build_related_resource(value, request=bundle.request)
        #END OF MODIFIED CONTENT

然后覆盖“top”模型中的obj_create&save_相关函数，或者在本例中是UserResource。以下是相关的覆盖：

def obj_create(self, bundle, request=None, **kwargs):
    """
    A ORM-specific implementation of ``obj_create``.
    """

    bundle.obj = self._meta.object_class()

    for key, value in kwargs.items():
        setattr(bundle.obj, key, value)

    bundle = self.full_hydrate(bundle)

    # Save the main object.
    # THIS HAS BEEN MOVED ABOVE self.save_related().
    bundle.obj.save()

    # Save FKs just in case.
    self.save_related(bundle)

    # Now pick up the M2M bits.
    m2m_bundle = self.hydrate_m2m(bundle)
    self.save_m2m(m2m_bundle)
    return bundle

def save_related(self, bundle):
    """
    Handles the saving of related non-M2M data.

    Calling assigning ``child.parent = parent`` & then calling
    ``Child.save`` isn't good enough to make sure the ``parent``
    is saved.

    To get around this, we go through all our related fields &
    call ``save`` on them if they have related, non-M2M data.
    M2M data is handled by the ``ModelResource.save_m2m`` method.
    """

    for field_name, field_object in self.fields.items():
        if not getattr(field_object, 'is_related', False):
            continue

        if getattr(field_object, 'is_m2m', False):
            continue

        if not field_object.attribute:
            continue

        # Get the object.
        # THIS HAS BEEN MOVED ABOVE the field_object.blank CHECK
        try:
            related_obj = getattr(bundle.obj, field_object.attribute)
        except ObjectDoesNotExist:
            related_obj = None

        # THE 'not related_obj' CHECK HAS BEEN ADDED
        if field_object.blank and not related_obj: # ADDED
            continue

        # Because sometimes it's ``None`` & that's OK.
        if related_obj:
            # THIS HAS BEEN ADDED
            setattr(related_obj, field_object.related_name, bundle.obj) # ADDED

            related_obj.save()
            setattr(bundle.obj, field_object.attribute, related_obj)

将这些添加到API后，一切都应该正常工作（至少在0.9.11上）。修复的主要部分是没有为ToOneField正确添加相关的对象。我的RelatedToOneField子类实现了对字段代码的检查

编辑：我又错了，ToOneField的0.9.12版仍然不起作用。我的问题是已经有一个UserProfileResource，它的数据与我试图在数据库中发布的数据相同。它只是抓住那一行并修改它，而不是创建新的内容

---

在这方面花费了太多时间之后，ToOneField的bug似乎在0.9.12版中得到了修复（有关讨论，请参见Pablo接受答案中的注释）

如果django-tastypie>=0.9.12，则以下操作应有效：

class UserResource(ModelResource):
    profile = fields.ToOneField('path.to.api.UserProfileResource', 'profile', related_name='user', full=True)

class UserProfileResource(ModelResource):
    home_address = fields.CharField(attribute='home_address')
    user = fields.ToOneField(UserResource, attribute='user', related_name='profile')

---

如果django tastypie我也有同样的问题。谢谢Pablo，我也有两天了！非常感谢。实际上我可能说得太快了。当我运行一个帖子时，它看起来确实起作用了。但当我再次尝试时，我得到了以下结果：“用户”字段没有数据，不允许空值。为了澄清，我现在可以使用它，但我必须让用户填写一个“ToManyField”（正如Pablo在评论中所建议的）。我还必须在profile字段中添加“null=True”。否则GET操作将无法工作。不管怎样，现在一切都好起来了。谢谢你的帮助，巴勃罗！你是怎么想到这个的？为什么会有什么不同？即使对方资源的模型没有对应关系，您是否在其上定义RelatedField？我没有对应关系，你的建议似乎对我没有任何影响。我觉得根本的问题是别的。

class UserResource(ModelResource):
    profile = fields.ToOneField('path.to.api.UserProfileResource', 'profile', related_name='user', full=True)

class UserProfileResource(ModelResource):
    home_address = fields.CharField(attribute='home_address')
    user = fields.ToManyField(UserResource, attribute='user', related_name='profile')