python - Django Rest Framework - Interrelated serializers -

given following models 2 have manytomany relationship first, how can construct serializer 3 models?

this importance of ordering in python turning issue.

class trail(models.model):     '''     main model application.  contains information particular trail     '''     trail_name = models.charfield(max_length=150)     active = models.booleanfield(default=true)     date_uploaded = models.datetimefield(default=now())     owner = models.foreignkey(account, default=1)       class meta:         ordering = ('trail_name', )  class activity(models.model):     '''     many many join table map activity name trail.  trail can have many     activities     '''     name = models.charfield(max_length=40, unique=true)     trails = models.manytomanyfield(trail)      class meta:         ordering = ('name', )   class surface(models.model):     '''     many many join table map surface type many trails.  trail can have many     surface types.     '''     type = models.charfield(max_length=50, db_column='surface_type', unique=true)     trails = models.manytomanyfield(trail)      class meta:         ordering = ('type', ) 

i have following serializers in serializers.py:

class trailserializer(serializers.modelserializer):     owner = accountserializer()     activities = activityserializer()      class meta:         model = trail         fields = ('trail_name', 'active', 'date_uploaded', 'owner', 'activities', )   class activityserializer(serializers.modelserializer):     trails = trailserializer()      class meta:         model = activity         fields = ('trails', 'name', )   class surfaceserializer(serializers.modelserializer):     trails = trailserializer()      class meta:         model = surface         fields = ('trails', 'type', ) 

my question is, short of creating file contain activityserializer , surfaceserializer, how can ensure trailserializer works expected in order include activity , surface references during serialization?

use marshmallow (serialization library inspired in part drf serializers). solves problem, allowing nested schemas reference strings. see marshmallow: 2 way nesting

class authorschema(schema):     # make sure use 'only' or 'exclude' params avoid infinite recursion     books = fields.nested('bookschema', many=true, exclude=('author', ))     class meta:         fields = ('id', 'name', 'books')  class bookschema(schema):     author = fields.nested(authorschema, only=('id', 'name'))     class meta:         fields = ('id', 'title', 'author') 

you can use directly or use via django-rest-marshmellow tom christie, allows use of marshmallow, while maintaining same api rest framework's serializer class.

i'm not aware of way achieve same result using drfs serializers.

see also: why marshmallow?