whoisearth
whoisearth

Reputation: 4160

django rest framework nested relationships

I have the following models - 

class Jobdtl(models.Model):
    jobdtl_id = models.IntegerField(primary_key=True)
    jobdtl_cmd = models.TextField(blank=True)
    jobdtl_envfile = models.TextField(blank=True)
    jobdtl_retnsn = models.SmallIntegerField(blank=True, null=True)
    jobdtl_allowadhoc = models.CharField(max_length=1, blank=True)
    jobdtl_waitop = models.CharField(max_length=1, blank=True)

    class Meta:
        managed = False
        db_table = 'jobdtl'

class Jobmst(models.Model):
    jobmst_id = models.IntegerField(primary_key=True)
    jobmst_prntid = models.IntegerField(blank=True, null=True)
    jobmst_active = models.CharField(max_length=1, blank=True)
    jobmst_evntoffset = models.SmallIntegerField(blank=True, null=True)
    jobmst_name = models.TextField(blank=True)
    jobmst_owner = models.IntegerField(blank=True, null=True)
    jobmst_crttm = models.DateTimeField()
    jobdtl_id = models.ForeignKey('Jobdtl', db_column='jobdtl_id', related_name='mstdtl', blank=True, null=True)
    jobmst_lstchgtm = models.DateTimeField(blank=True, null=True)
    def __unicode__(self):
        return self.jobmst_name   
    class Meta:
        managed = False
        db_table = 'jobmst'

I'm trying to generate a json similar to what we have here -

http://stackoverflow.com/questions/19709101/django-rest-framework-multiple-models

using the steps here -

http://stackoverflow.com/questions/16793608/how-to-write-a-django-rest-framework-serializer-field-to-merge-data-from-gener

These are my serializers -

class JobmstSerializer(serializers.ModelSerializer):

    class Meta:
        model = Jobmst

class JobdtlSerializer(serializers.ModelSerializer):
    jobmst_id = JobmstSerializer(many=True)

    class Meta:
        model = Jobdtl

And this is my view

class ResultsList(ListAPIView):
    def list(self, request, *args, **kwargs):
        jobmstquery = Jobmst.objects.using('Admiral').all()
        jobdtlquery = Jobdtl.objects.using('Admiral').all()

        results = list()
        entries = list(chain(jobmstquery, jobdtlquery)) # combine the two querysets
        for entry in entries:
            type = entry.__class__.__name__.lower() # 'jobmst', 'jobdtl'
            if isinstance(entry, Jobmst):
                serializer = JobmstSerializer(entry)
                dictionary = {'type': jobmst, 'jobmst_id': jobmst_id, 'jobmst_type': jobmst_type, 'jobmst_prntid': jobmst_prntid, 'jobmst_active': jobmst_active, 'evntmst_id': evntmst_id, 'jobmst_evntoffset': jobmst_evntoffset, 'jobmst_name': jobmst_name, 'jobmst_mode': jobmst_mode, 'jobmst_owner': jobmst_owner, 'jobmst_desc': jobmst_desc, 'jobmst_crttm': jobmst_crttm, 'jobdtl_id': jobdtl_id, 'jobmst_lstchgtm': jobmst_lstchgtm}
            if isinstance(entry, Jobdtl):
                serializer = JobdtlSerializer(entry)
                dictionary = {'type': jobdtl, 'jobdtl_id': jobdtl, 'jobdtl_cmd': jobdtl_cmd, 'jobdtl_envfile': jobdtl_envfile, 'jobdtl_retnsn': jobdtl_retnsn, 'jobdtl_allowadhoc': jobdtl_allowadhoc, 'jobdtl_waitop': jobdtl_waitop}
            results.append(dictionary)
        return Response(results)

I tie it through my URL -

urlpatterns = patterns('TidalDEV.views',
    url(r'^TidalDEV/$', 'ResultsList'),
    url(r'^TidalDEV/(?P<pk>[0-9]+)/$', 'ResultsList'),
)

But when I hit my URL at http://localhost/TidalDEV/ or http://localhost/TidalDEV/50244/

I get slammed with an error -

Exception Type:     TypeError
Exception Value:    

__init__() takes 1 positional argument but 2 were given

Exception Location:     D:\Python33\lib\site-packages\django\core\handlers\base.py in get_response, line 114

Upvotes: 1

Views: 1885

Answers (1)

whoisearth
whoisearth

Reputation: 4160

I ended up doing the following and it worked -

class JobdtlSerializer(serializers.ModelSerializer):

    class Meta:
        model = Jobdtl

class JobmstSerializer(serializers.ModelSerializer):
    jobdtl_id = JobdtlSerializer()

    class Meta:
        model = Jobmst

then connected with the variation of the default views -

@csrf_exempt
def jobmst_list(request):
    """
    List all code snippets, or create a new snippet.
    """
    if request.method == 'GET':
        DEV = Jobmst.objects.using('AdmiralDEV').all()
        serializer = JobmstSerializer(DEV, many=True)
        return XMLResponse(serializer.data)

    elif request.method == 'POST':
        data = XMLParser().parse(request)
        serializer = JobmstSerializer(data=data)
        if serializer.is_valid():
            serializer.save()
            return XMLResponse(serializer.data, status=201)
        else:
            return XMLResponse(serializer.errors, status=400)

@csrf_exempt
def jobmst_detail(request, pk):
    """
    Retrieve, update or delete a code snippet.
    """
    try:
        DEV = Jobmst.objects.using('AdmiralDEV').get(jobmst_id=pk)
    except Jobmst.DoesNotExist:
        return HttpResponse(status=404)

    if request.method == 'GET':
        serializer = JobmstSerializer(DEV)
        return XMLResponse(serializer.data)

    elif request.method == 'PUT':
        data = XMLParser().parse(request)
        serializer = JobmstSerializer(DEV, data=data)
        if serializer.is_valid():
            serializer.save()
            return XMLResponse(serializer.data)
        else:
            return XMLResponse(serializer.errors, status=400)

    elif request.method == 'DELETE':
        DEV.delete()
        return HttpResponse(status=204)

That allowed me to get from the 2 separate models. It's unformatted and ugly but proves it can be done. Need to figure out how to link more than these 2 models now (I have 5 minimum).

Upvotes: 1

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