Django REST framework not looking for URL encoded detail views

Question

I have a model whose Primary Key is a TextField. This is a minimalistic reproduction of my issue:

Model:

class Filename(models.Model):
    path = models.TextField(primary_key=True)

Serializer:

class FilenameSerializer(ModelSerializer):
    class Meta:
        model = Filename
        fields = '__all__'

View:

class FilenameViewSet(ModelViewSet):
    queryset = Filename.objects.all()
    serializer_class = FilenameSerializer

I'm using a DefaultRouter for URLs. Here is the problem: If I sent {"path":"test"} with a POST /filename/ I can perfectly retrieve my object with GET /filename/test/ as you would expect. However, if I POST /filename/ something like {"path":"c:\\test"} I would expect either GET /filename/c%3A%5Ctest/ or GET /filename/c%3A%5C%5Ctest/ to be the proper way to get it, but none of those works. Does anybody knows what's going on?

Update: The webserver logs show Not Found: /filename/c:\test so it's being decoded properly at some moment. Maybe some URL regex issue?

I doubt is very relevant for this question in particular, but python=3.7, django=2.1.2 and djangorestframework=3.8.2 — lithiium, Oct 12 '18 at 09:16
The `path` simply stores "`test"`, so the query `SELECT * FROM filename WHERE path = 'C:\\test'` fails, hence nothing is returned. For the database this is just a string, whether that string "happens" to be a filepath is irrelevant. — Willem Van Onsem, Oct 12 '18 at 09:18
@WillemVanOnsem I'm of course creating the c:\test object. The second POST with the json data is in the question too :) — lithiium, Oct 12 '18 at 09:22

score 3 · Accepted Answer · answered Oct 12 '18 at 11:20

The issue was not with any URL encoded in general, but with the dot (%2E) in particular. The DefaultRouter() does not match the dots by default. This behavior can be modified setting the lookup_value_regex attribute in the ViewSet.

class FilenameViewSet(ModelViewSet):
    queryset = Filename.objects.all()
    serializer_class = FilenameSerializer
    lookup_value_regex = '[^/]+'

aman kumar · Answer 2 · 2018-10-12T09:25:14.433

0

hey you have to define the lookupfield , you can overide the get_object change string format to a norma text

class FilenameViewSet(ModelViewSet):
   queryset = Filename.objects.all()
   serializer_class = FilenameSerializer
   lookup_field = 'path'

def get_object(self):
   try:
      from urllib import unquote
   except ImportError:
      from urllib.parse import unquote
  path = unquote(kwarhs['path'))
  return self.get_queryset.get(path=path)

edited Oct 12 '18 at 09:25

answered Oct 12 '18 at 09:18

aman kumar

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I tried, but it's not working neither. I don't think that's the issue as non-url-encoded files are found fine. By default the lookup_field should be the pk anyway. – lithiium Oct 12 '18 at 09:21
By default the `lookup_field` is the primary key IIRC. – Willem Van Onsem Oct 12 '18 at 09:21
you can overide the get_object method – aman kumar Oct 12 '18 at 09:25
The get_object method is not even being called. The logs shows me `Not Found: /filename/c:\test` so django is decoding it properly.... maybe a URL path issue? – lithiium Oct 12 '18 at 09:44

score 0 · Answer 3 · answered Oct 12 '18 at 10:08

0

if im getting your question correctly . you problem is with json format . On adding escape character \ before special characters would resolve your issue.

see this link below: How to escape special characters in building a JSON string?

answered Oct 12 '18 at 10:08

Babak Abadkheir

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Hi babak, the JSON is working fine, the POST are successful. The issue is getting the object back via a GET request. – lithiium Oct 12 '18 at 10:12
i think you can validate your return obj in your return call. try to use valid() in modelserializer. – Babak Abadkheir Oct 12 '18 at 10:20

Django REST framework not looking for URL encoded detail views

3 Answers3