Django Concurrency Package: DRF Integration Example

Here's an example of using the Django concurrency package with Django Rest Framework:

First, install the package:

$ pip install django-transactional-requests

Then, add it to your 'INSTALLED_APPS' in your Django settings file:

INSTALLED_APPS = [
    # ...
    'django.contrib.contenttypes',
    'django.contrib.auth',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'rest_framework',
    'django.contrib.admin',
    'django.contrib.admindocs',
    'django.contrib.sites',
    'django.contrib.humanize',
    'django-transactional-requests',
    # ...
]

Next, define your model with the 'VersionedModel' mixin:

from concurrency.fields import AutoIncVersionField
from concurrency.api import concurrency_check

class MyModel(models.Model, VersionedModel):
    name = models.CharField(max_length=255)
    version = AutoIncVersionField()

    @concurrency_check
    def save(self, *args, **kwargs):
        super(MyModel, self).save(*args, **kwargs)

In this example, we're using the 'AutoIncVersionField' to keep track of the version of the model. We're also using the 'concurrency_check' decorator to ensure that concurrent requests are handled correctly.

Now, let's create a view using Django Rest Framework:

from rest_framework.generics import RetrieveUpdateAPIView
from myapp.models import MyModel
from myapp.serializers import MyModelSerializer

class MyModelView(RetrieveUpdateAPIView):
    queryset = MyModel.objects.all()
    serializer_class = MyModelSerializer

In this example, we're using 'RetrieveUpdateAPIView' to handle GET and PUT requests for our 'MyModel' model. We're also using 'MyModelSerializer' to serialize and deserialize our model.

Finally, let's define our serializer:

from rest_framework import serializers
from myapp.models import MyModel

class MyModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = MyModel
        fields = '__all__'
        extra_kwargs = {
            'version': {'read_only': True}
        }

In this example, we're using 'ModelSerializer' to automatically generate our serializer based on our 'MyModel' model. We're also setting the 'version' field to be read-only, since it's managed by the concurrency package.

That's it! Now you can use the 'MyModelView' view to retrieve and update 'MyModel' instances with concurrency handling.