Docs improvement Subscriptions

docs/guide/subscriptions.md

@@ -1,6 +1,136 @@
-### Subscriptions
+# Subscriptions
 
 Subscriptions are supported using the
 [Strawberry Django Channels](https://strawberry.rocks/docs/integrations/channels) integration.
 
-Check its docs to know how to use it.
+This guide will give you a minimal working example to get you going.
+There are 3 parts to this guide:
+
+1. Making Django compatible
+2. Setup local testing
+3. Creating your first subscription
+
+## Making Django compatible
+
+It's important to realise that Django doesnt support websockets out of the box.
+To resolve this, we can help the platform along a little.
+
+Edit your `MyProject.asgi.py` file and replace it with the following content.
+Ensure that you replace the relevant code with your setup.
+
+```python
+# MyProject.asgi.py
+import os
+
+from django.core.asgi import get_asgi_application
+from strawberry.channels import GraphQLProtocolTypeRouter
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "MyProject.settings")  # CHANGE the project name
+django_asgi_app = get_asgi_application()
+
+# Import your Strawberry schema after creating the django ASGI application
+# This ensures django.setup() has been called before any ORM models are imported
+# for the schema.
+
+from .schema import schema  # CHANGE path to where you housed your schema file.
+
+
+application = GraphQLProtocolTypeRouter(
+    schema,
+    django_application=django_asgi_app,
+)
+```
+
+Also, ensure that you enable subscriptions on your AsgiGraphQLView in `MyProject.urls.py`:
+
+```python
+...
+
+urlpatterns = [
+	...
+    path('graphql/', AsyncGraphQLView.as_view(
+        schema=schema,
+        graphiql=settings.DEBUG,
+        subscriptions_enabled=True
+        )
+    ),
+    ...
+]
+
+```
+
+Note, django-channels allows for a lot more complexity. Here we just cover the basic framework to get
+subscriptions to run on Django with minimal effort.
+
+## Setup local testing
+
+The classic `./manage.py runserver` will not support subscriptions. However, Django has daphne support out of the box to ensure that we can actually use Daphne for the runserver command. [Source](https://docs.djangoproject.com/en/4.2/howto/deployment/asgi/daphne/)
+
+Firstly, we need install Daphne to handle the workload, so let's install it:
+
+```bash
+pip install daphne
+```
+
+Secondly, we need to add `daphne` to your settings.py file before 'django.contrib.staticfiles'
+
+```python
+INSTALLED_APPS = [
+	...
+    'daphne',
+    'django.contrib.staticfiles',
+    ...
+]
+```
+
+and add your ASGI_APPLICATION setting in your settings.py
+
+```python
+# settings.py
+...
+ASGI_APPLICATION = 'MyProject.asgi.application'
+...
+```
+
+Now you can run your test-server like as usual:
+
+```bash
+./manage.py runserver
+```
+
+## Creating your first subscription
+
+Once you've taken care of those 2 setup steps, your first subscription is a breeze.
+Go and edit your schema-file and add:
+
+```python
+from strawberry import type, subscription
+import asyncio
+
+@type
+class Subscription:
+    @subscription
+    async def count(self, target: int = 100) -> int:
+        for i in range(target):
+            yield i
+            await asyncio.sleep(0.5)
+```
+
+That's pretty much it for this basic start.
+See for yourself by running your test server `./manange.py runserver` and opening `http://127.0.0.1:8000/graphql/` in your browser. Now run:
+
+```graphql
+subscription {
+  count(target: 10)
+}
+```
+
+You should see something like (where the count changes every .5s to a max of 9)
+
+```json
+{
+  "data": {
+    "count": 9
+  }
+}
+```