Tastypie queryset on child resource not working

contracts.py

"""
API resources
"""
# Django imports
from django import forms
from django.db.models import Count
from django.utils.datastructures import SortedDict
from django.contrib.contenttypes.models import ContentType

# 3rd party imports
from tastypie import fields
from tastypie.authentication import ApiKeyAuthentication
from tastypie.constants import ALL, ALL_WITH_RELATIONS
from tastypie.validation import FormValidation

# Project imports
from ..authorization.contracts import ContractsAuthorization

# Core app imports
from vbenergyzone.core.models.contracts import Contract
from vbenergyzone.core.models.documents import Document
from vbenergyzone.core.models.permissions import get_permissions

from ..paginator import BackbonePaginator
from . import ResourceBase
from .customers import CustomersResource
from .partners import PartnersResource
from .suppliers import SuppliersResource

# ==============================================================================

class ContractValidationForm(forms.ModelForm):    #pylint: disable=R0924
    """
    Define a form for validation.
    """
    class Meta: # pylint: disable=C1001, W0232, C0111, R0903
        fields = (
            'name',
        )

        model = Contract

class ContractsResource(ResourceBase):
    customer = fields.ToOneField(
        attribute='customer',
        blank=True,
        full=True,
        null=True,
        to=CustomersResource,
    )

    number_of_documents = fields.IntegerField(attribute='number_of_documents', readonly=True)

    partner = fields.ToOneField(
        attribute='partner',
        blank=True,
        full=True,
        null=True,
        to=PartnersResource,
    )

    product_type_display = fields.CharField(readonly=True)

    supplier = fields.ToOneField(
        attribute='supplier',
        blank=True,
        full=True,
        null=True,
        to=SuppliersResource,
    )

    workflow_state_display = fields.CharField(readonly=True)

    class Meta:
        always_return_data = True
        authentication = ApiKeyAuthentication()
        authorization = ContractsAuthorization()
        collection_name = 'objects'
        detail_allowed_methods = ['delete', 'get', 'put']

        fields = [
            'id',
            'end_date',
            'estimated_annual_load_factor',
            'estimated_annual_volume',
            'name',
            'number_of_documents',
            'price',
            'product_type',
            'start_date',
            'workflow_state',
        ]

        filtering = {
            'customer'      : ALL,
            'end_date'      : ALL,
            'name'          : ALL,
            'partner'       : ALL,
            'price'         : ALL,
            'start_date'    : ALL,
            'supplier'      : ALL,
            'product_type'  : ALL,
            'workflow_state': ALL,
        }

        include_absolute_url = True
        limit = 10
        list_allowed_methods = ['get', 'post']
        max_limit = 100

        ordering = [
            'customer',
            'end_date',
            'estimated_annual_load_factor'
            'estimated_annual_volume',
            'name',
            'number_of_documents',
            'partner',
            'price',
            'product_type',
            'start_date',
            'supplier',
            'workflow_state',
        ]

        paginator_class = BackbonePaginator
        content_type = ContentType.objects.get(app_label='core', model='contract')

        number_of_documents_select = (
            "select count(*) from core_document, eee_core_attachment "
            "where parent_type_id = %s and parent_id = core_contract.id "
            "and core_document.attachment_ptr_id = eee_core_attachment.id" 
            % content_type.id
        )
        
        queryset = Contract.objects.extra(
            select={'number_of_documents':number_of_documents_select},
        ).order_by('name')

        resource_name = 'contracts'
        validation = FormValidation(form_class=ContractValidationForm)

    def alter_list_data_to_serialize(self, request, data):
        subset = 'contracts'
        permissions = get_permissions(request.user, [subset])

        deletable_obj_ids = (
            [o.id for o in permissions[subset]['deletable_objs']]
        )

        updatable_obj_ids = (
            [o.id for o in permissions[subset]['updatable_objs']]
        )

        viewable_obj_ids = (
            [o.id for o in permissions[subset]['viewable_objs']]
        )

        for bundle in data['objects']:
            obj = bundle.data
            obj['deletable'] = obj['id'] in deletable_obj_ids
            obj['updatable'] = obj['id'] in updatable_obj_ids
            obj['viewable'] = obj['id'] in viewable_obj_ids

        permissions[subset].pop('deletable_objs', None)
        permissions[subset].pop('updatable_objs', None)
        permissions[subset].pop('viewable_objs', None)

        data['meta']['permissions'] = permissions
        return data

    def apply_sorting(self, obj_list, options=None):
        options = options.copy()

        if 'sort_by' in options:
            if 'order' in options:
                if options['order'] == 'desc':
                    options['sort_by'] = '-' + options['sort_by']

            if options['sort_by'] == 'customer':
                obj_list = obj_list.order_by('customer__name')
            elif options['sort_by'] == '-customer':
                obj_list = obj_list.order_by('-customer__name')
            elif options['sort_by'] == 'partner':
                obj_list = obj_list.order_by('partner__name')
            elif options['sort_by'] == '-partner':
                obj_list = obj_list.order_by('-partner__name')
            elif options['sort_by'] == 'supplier':
                obj_list = obj_list.order_by('supplier__name')
            elif options['sort_by'] == '-supplier':
                obj_list = obj_list.order_by('-supplier__name')
            else:
                obj_list = obj_list.order_by(options['sort_by'])

        return obj_list

    def build_filters(self, filters=None):
        if filters is None:
            filters = {}

        orm_filters = super(ContractsResource, self).build_filters(filters)

        if "q" in filters:
            search_string = filters['q']
            search_terms = search_string.split()

            choices = Contract._meta.get_field('workflow_state').choices
            workflow_state_values = [choice[0] for choice in choices]
            workflow_state_displays = [choice[1] for choice in choices]

            choices = Contract._meta.get_field('product_type').choices
            product_type_values = [choice[0] for choice in choices]
            product_type_displays = [choice[1] for choice in choices]

            sqs = Contract.objects.filter(pk=-1)

            for search_term in search_terms:
                sqs |= Contract.objects.filter(name__icontains=search_term)
                sqs |= Contract.objects.filter(customer__name__icontains=search_term)
                sqs |= Contract.objects.filter(partner__name__icontains=search_term)
                sqs |= Contract.objects.filter(supplier__name__icontains=search_term)

                for workflow_state_display in workflow_state_displays:
                    if search_term.upper() in workflow_state_display.upper():
                        index = workflow_state_displays.index(workflow_state_display)
                        workflow_state_value = workflow_state_values[index]
                        sqs |= Contract.objects.filter(workflow_state=workflow_state_value)

                for product_type_display in product_type_displays:
                    if search_term.upper() in product_type_display.upper():
                        index = product_type_displays.index(product_type_display)
                        product_type_value = product_type_values[index]
                        sqs |= Contract.objects.filter(product_type=product_type_value)

            orm_filters["pk__in"] = [i.pk for i in sqs]

        return orm_filters

    def dehydrate_customer(self, bundle):
        retval = None
        contract = bundle.obj
        customer = contract.customer

        if customer:
            retval = {
                "id": customer.id,
                "name": customer.name,
                "resource_uri": bundle.data['customer'].data['resource_uri'],
            }

        return retval

    def dehydrate_estimated_annual_load_factor(self, bundle):
        contract = bundle.obj
        return contract.get_estimated_annual_load_factor()

    def dehydrate_estimated_annual_volume(self, bundle):
        contract = bundle.obj
        return contract.get_estimated_annual_volume()

    def dehydrate_number_of_documents(self, bundle):
        contract = bundle.obj
        return contract.number_of_documents

    def dehydrate_partner(self, bundle):
        retval = None
        contract = bundle.obj
        partner = contract.partner

        if partner:
            retval = {
                "id": partner.id,
                "name": partner.name,
                "resource_uri": bundle.data['partner'].data['resource_uri'],
            }

        return retval

    def dehydrate_product_type_display(self, bundle):
        contract = bundle.obj
        return contract.get_product_type_display()

    def dehydrate_supplier(self, bundle):
        retval = None
        contract = bundle.obj
        supplier = contract.supplier

        if supplier:
            retval = {
                "id": supplier.id,
                "name": supplier.name,
                "resource_uri": bundle.data['supplier'].data['resource_uri'],
            }

        return retval

    def dehydrate_workflow_state_display(self, bundle):
        contract = bundle.obj
        return contract.get_workflow_state_display()

customers.py

"""
API resources
"""
# Django imports
from django import forms
from django.db.models import Count

# 3rd party imports
from tastypie import fields
from tastypie.authentication import ApiKeyAuthentication
from tastypie.constants import ALL, ALL_WITH_RELATIONS
from tastypie.exceptions import Unauthorized
from tastypie.validation import FormValidation

# Project imports
from ..authorization.customers import CustomersAuthorization

# Core app imports
from vbenergyzone.core.models.customers import Customer
from vbenergyzone.core.models.permissions import get_permissions

from ..paginator import BackbonePaginator
from . import ResourceBase

# ==============================================================================

class CustomerValidationForm(forms.ModelForm):    #pylint: disable=R0924
    """
    Define a meter form for validation.
    """
    class Meta: # pylint: disable=C1001, W0232, C0111, R0903
        fields = (
            'customer_type',
            'name',
        )

        model = Customer

class CustomersResource(ResourceBase):
    active_suppliers = fields.ListField(readonly=True)
    last_expiring_contract = fields.DictField(readonly=True)

    last_usage_end_date = fields.DateTimeField(
        attribute='_last_usage_end_date',
        blank=True,
        null=True,
        readonly=True,
    )

    number_of_meters = fields.IntegerField(
        attribute='number_of_meters',
        blank=True,
        null=True,
        readonly=True,
    )

    # TODO tags =

    class Meta:
        always_return_data = True
        authentication = ApiKeyAuthentication()
        authorization = CustomersAuthorization()
        collection_name = 'objects'
        detail_allowed_methods = ['delete', 'get', 'put']

        fields = [
            'active',
            'active_suppliers',
            'customer_type',
            'duns_number',
            'estimated_annual_volume',
            'id',
            'last_expiring_contract',
            'last_usage_end_date',
            'legal_name',
            'name',
            'notes',
            'number_of_meters',
            'taxpayer_id_number',
        ]

        filtering = {
            "name": ALL,
        }

        include_absolute_url = True
        limit = 10
        list_allowed_methods = ['get', 'post']
        max_limit = 100

        ordering = [
            'estimated_annual_volume',
            'last_usage_end_date',
            'name',
            'number_of_meters'
        ]

        paginator_class = BackbonePaginator

        number_of_meters_select = (
            "select count(*) from core_meter "
            "where core_meter.customer_id = core_customer.organization_ptr_id"
        )

        queryset = Customer.objects.extra(
            select={'number_of_meters':number_of_meters_select},
        ).order_by('name')
        
        resource_name = 'customers'
        validation = FormValidation(form_class=CustomerValidationForm)

    def alter_list_data_to_serialize(self, request, data):
        user = request.user
        user_type = user.user_profile.user_type()
        subset = 'customers'
        permissions = get_permissions(request.user, [subset])

        deletable_obj_ids = (
            [o.id for o in permissions[subset]['deletable_objs']]
        )

        updatable_obj_ids = (
            [o.id for o in permissions[subset]['updatable_objs']]
        )

        viewable_obj_ids = (
            [o.id for o in permissions[subset]['viewable_objs']]
        )

        for bundle in data['objects']:
            obj = bundle.data
            obj['deletable'] = obj['id'] in deletable_obj_ids
            obj['updatable'] = obj['id'] in updatable_obj_ids
            obj['viewable'] = obj['id'] in viewable_obj_ids

            if user_type == "supplier":
                obj.pop('active_suppliers', None)
                obj.pop('last_expiring_contract', None)

        permissions[subset].pop('deletable_objs', None)
        permissions[subset].pop('updatable_objs', None)
        permissions[subset].pop('viewable_objs', None)

        data['meta']['permissions'] = permissions
        return data

    def build_filters(self, filters=None):
        if filters is None:
            filters = {}

        orm_filters = super(CustomersResource, self).build_filters(filters)

        if "q" in filters:
            search_string = filters['q']
            search_terms = search_string.split()
            sqs = Customer.objects.filter(pk=-1)

            for search_term in search_terms:
                sqs |= Customer.objects.filter(name__icontains=search_term)

            orm_filters["pk__in"] = [i.pk for i in sqs]

        return orm_filters

    def dehydrate_active_suppliers(self, bundle):
        customer = bundle.obj
        active_suppliers = (
            [{"id": supplier.id, "name": supplier.name}
                for supplier in customer.active_suppliers()]
        )
        return active_suppliers

    def dehydrate_last_expiring_contract(self, bundle):
        customer = bundle.obj
        contract = customer.last_expiring_contract()
        retval = None

        if contract:
            retval = {
                "end_date"  : contract.end_date,
                "id"        : contract.id,
                "name"      : contract.name,
            }

        return retval

    def dehydrate_number_of_meters(self, bundle):
        customer = bundle.obj
        return customer.number_of_meters
        # try:
        #     return customer.number_of_meters
        # except AttributeError:
        #     return None

For http://stackoverflow.com/questions/21638401/tastypie-queryset-on-child-resource-not-working.