Feature/17 (#19)

* add turbo_stream_from

.github/workflows/runtests.yml

@@ -9,9 +9,16 @@ on:
 jobs:
   runtests:
     runs-on: ubuntu-latest
+    env:
+      CHANNELS_REDIS: redis://localhost:6379/0
     strategy:
       matrix:
         python-version: ['3.8', '3.9', '3.10' ]
+    services:
+      redis:
+        image: redis
+        ports:
+          - 6379:6379
     steps:
       - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}

docs/source/channels.md

@@ -1,5 +1,9 @@
 # Django-Channels
 
+```{warning}
+This approach is not recommended anymore, please consider using [turbo_stream_from](./template-tags.md#turbo-stream-from) instead.
+```
+
 This library can also be used with [django-channels](https://channels.readthedocs.io/en/stable/). As with multiple streams, you can use the **TurboStream** class to broadcast turbo-stream content from your consumers.
 
 ```python
@@ -53,6 +57,3 @@ export default class extends Controller {
   }
 }
 ```
-
-**Note** if you want to add reactivity directly to your models, so that model changes broadcast turbo-streams automatically, we recommend the [turbo-django](https://github.com/hotwire-django/turbo-django) package.
-

docs/source/conf.py

@@ -22,8 +22,8 @@
 # -- Project information -----------------------------------------------------
 
 project = "django-turbo-response"
-copyright = f"{datetime.datetime.now().year}, Dan Jacob"
-author = "Dan Jacob"
+copyright = f"{datetime.datetime.now().year}, Michael Yin"
+author = "Michael Yin"
 
 
 # -- General configuration ---------------------------------------------------

docs/source/template-tags.md

@@ -94,4 +94,51 @@ This can help render `turbo-cable-stream-source` in Django template
 
 `<turbo-cable-stream-source>` is a custom element provided by [turbo-rails](https://github.com/hotwired/turbo-rails/blob/097d8f90cf0c5ed24ac6b1a49cead73d49fa8ab5/app/javascript/turbo/cable_stream_source_element.js), with it, we can send Turbo Stream over the websocket connection and update the page in real time.
 
-The `<turbo-cable-stream-source>` is built on Rails ActionCable, which provide many great feature out of the box, such as `Automatic Reconnection`, so we can focus on the business logic.
+To import `turbo-cable-stream-source` element to the frontend, there are two ways:
+
+```html
+<script type="module">
+  import 'https://cdn.jsdelivr.net/npm/@hotwired/[email protected]/+esm'
+</script>
+```
+
+Or you can [Jump start frontend project bundled by Webpack](https://github.com/AccordBox/python-webpack-boilerplate#jump-start-frontend-project-bundled-by-webpack) and install it via `npm install`
+
+After frontend work is done, to support Actioncable on the server, please install [django-actioncable](https://github.com/AccordBox/django-actioncable).
+
+In `routing.py`, register `TurboStreamCableChannel`
+
+```python
+from actioncable import cable_channel_register
+from turbo_response.cable_channel import TurboStreamCableChannel
+
+cable_channel_register(TurboStreamCableChannel)
+```
+
+In Django template, we can subscribe to stream source like this:
+
+```html
+{% load turbo_helper %}
+
+{% turbo_stream_from 'chat' view.kwargs.chat_pk %}
+```
+
+`turbo_stream_from` can accept multiple positional arguments
+
+Then in Python code, we can send Turbo Stream to the stream source like this
+
+```python
+from turbo_response.channel_helper import broadcast_render_to
+
+broadcast_render_to(
+    ["chat", instance.chat_id],
+    template="message_append.turbo_stream.html",
+    context={
+        "instance": instance,
+    },
+)
+```
+
+The `["chat", instance.chat_id]` **should** match the positional arguments in the `turbo_stream_from` tag.
+
+The web page can be updated in real time, through Turbo Stream over Websocket.

src/turbo_response/cable_channel.py

@@ -0,0 +1,27 @@
+from django.core.signing import Signer
+
+from .channel_helper import verify_signed_stream_key
+
+try:
+    from actioncable import ActionCableConsumer, CableChannel
+except ImportError as err:
+    raise Exception("Please make sure django-actioncable is installed") from err
+
+signer = Signer()
+
+
+class TurboStreamCableChannel(CableChannel):
+    def __init__(self, consumer: ActionCableConsumer, identifier_key, params=None):
+        self.params = params if params else {}
+        self.identifier_key = identifier_key
+        self.consumer = consumer
+        self.group_name = None
+
+    async def subscribe(self):
+        flag, stream_name = verify_signed_stream_key(self.params["signed_stream_name"])
+        self.group_name = stream_name
+        if flag:
+            await self.consumer.subscribe_group(self.group_name, self)
+
+    async def unsubscribe(self):
+        await self.consumer.unsubscribe_group(self.group_name, self)

src/turbo_response/channel_helper.py

@@ -1,4 +1,3 @@
-import json
 from typing import List, Tuple, Union
 
 from django.core import signing
@@ -8,8 +7,7 @@
 from .templatetags.turbo_helper import dom_id
 
 try:
-    from asgiref.sync import async_to_sync
-    from channels.layers import get_channel_layer
+    from actioncable import cable_broadcast
 except ImportError as err:
     raise Exception("Please make sure django-channels is installed") from err
 
@@ -48,36 +46,32 @@ def verify_signed_stream_key(signed_stream_key: str) -> Tuple[bool, str]:
     return False, ""
 
 
-def generate_channel_group_name(channel: str, stream_name: str):
-    """
-    Generate Django Channel group name from channel and stream_name
+def broadcast_render_to(streamables: Union[List, object], template: str, context=None):
     """
-    return f"{channel}_{stream_name}"
+    This function help render HTML to Turbo Stream Channel
 
+    for example, in Django template, we subscribe to a Turbo stream Channel
 
-def broadcast_render_to(streamables: Union[List, object], template: str, context=None):
+    {% turbo_stream_from 'chat' view.kwargs.chat_pk %}
+
+    Then in Python code
+
+    broadcast_render_to(
+        ["chat", instance.chat_id],
+        template="message_append.turbo_stream.html",
+        context={
+            "instance": instance,
+        },
+    )
+    """
     if context is None:
         context = {}
 
     html = render_to_string(template, context=context)
-
     stream_name = stream_name_from(streamables)
-    channel_group_name = generate_channel_group_name("TurboStreamsChannel", stream_name)
-
-    channel_layer = get_channel_layer()
-    async_to_sync(channel_layer.group_send)(
-        channel_group_name,
+    cable_broadcast(
+        stream_name,
         {
-            "type": "turbo_stream_message",
-            "data": {
-                "identifier": json.dumps(
-                    {
-                        "channel": "TurboStreamsChannel",
-                        "signed_stream_name": generate_signed_stream_key(stream_name),
-                    },
-                    separators=(",", ":"),
-                ),
-                "message": html,
-            },
+            "message": html,
         },
     )

src/turbo_response/templatetags/turbo_helper.py

@@ -110,12 +110,16 @@ def render(self, context):
 
 class TurboStreamFromTagNode(Node):
     def __init__(self, stream_name_array):
+        """
+        TODO: Support override channel
+        """
         self.stream_name_array = stream_name_array
 
     def __repr__(self):
         return "<%s>" % self.__class__.__name__
 
     def render(self, context):
+        from ..cable_channel import TurboStreamCableChannel
         from ..channel_helper import generate_signed_stream_key, stream_name_from
 
         stream_name_array = [
@@ -124,9 +128,10 @@ def render(self, context):
         stream_name_string = stream_name_from(stream_name_array)
 
         django_engine = engines["django"]
-        template_string = """<turbo-cable-stream-source channel="TurboStreamsChannel" signed-stream-name="{{ signed_stream_name }}"></turbo-cable-stream-source>"""
+        template_string = """<turbo-cable-stream-source channel="{{ channel }}" signed-stream-name="{{ signed_stream_name }}"></turbo-cable-stream-source>"""
         context = {
             "signed_stream_name": generate_signed_stream_key(stream_name_string),
+            "channel": TurboStreamCableChannel.__name__,
         }
         return django_engine.from_string(template_string).render(context)
 

tests/conftest.py

@@ -1,3 +1,4 @@
+import os
 import pathlib
 
 import pytest
@@ -35,6 +36,14 @@ def pytest_configure():
             "tests.testapp.apps.TestAppConfig",
         ],
         ROOT_URLCONF="tests.testapp.urls",
+        CHANNEL_LAYERS={
+            "default": {
+                "BACKEND": "channels_redis.pubsub.RedisPubSubChannelLayer",
+                "CONFIG": {
+                    "hosts": [os.getenv("CHANNEL_LAYERS", "redis://localhost:6379/0")],
+                },
+            },
+        },
     )
 
 

tests/test_cable_channel.py

@@ -0,0 +1,85 @@
+import pytest
+from actioncable import ActionCableConsumer, cable_channel_register, compact_encode_json
+from channels.layers import get_channel_layer
+from channels.testing import WebsocketCommunicator
+
+from turbo_response.cable_channel import TurboStreamCableChannel
+from turbo_response.channel_helper import generate_signed_stream_key
+
+# register the TurboStreamCableChannel
+cable_channel_register(TurboStreamCableChannel)
+
+
+@pytest.mark.asyncio
+async def test_subscribe():
+    communicator = WebsocketCommunicator(
+        ActionCableConsumer.as_asgi(), "/cable", subprotocols=["actioncable-v1-json"]
+    )
+    connected, subprotocol = await communicator.connect(timeout=10)
+    assert connected
+    response = await communicator.receive_json_from()
+    assert response == {"type": "welcome"}
+
+    # Subscribe
+    group_name = "test"
+    subscribe_command = {
+        "command": "subscribe",
+        "identifier": compact_encode_json(
+            {
+                "channel": TurboStreamCableChannel.__name__,
+                "signed_stream_name": generate_signed_stream_key(group_name),
+            }
+        ),
+    }
+
+    await communicator.send_to(text_data=compact_encode_json(subscribe_command))
+    response = await communicator.receive_json_from(timeout=10)
+    assert response["type"] == "confirm_subscription"
+
+    # Message
+    channel_layer = get_channel_layer()
+    await channel_layer.group_send(
+        group_name,
+        {
+            "type": "message",
+            "group": group_name,
+            "data": {
+                "message": "html_snippet",
+            },
+        },
+    )
+
+    response = await communicator.receive_json_from(timeout=5)
+    assert response["message"] == "html_snippet"
+
+    # Unsubscribe
+    group_name = "test"
+    subscribe_command = {
+        "command": "unsubscribe",
+        "identifier": compact_encode_json(
+            {
+                "channel": TurboStreamCableChannel.__name__,
+                "signed_stream_name": generate_signed_stream_key(group_name),
+            }
+        ),
+    }
+
+    await communicator.send_to(text_data=compact_encode_json(subscribe_command))
+
+    # Message
+    channel_layer = get_channel_layer()
+    await channel_layer.group_send(
+        group_name,
+        {
+            "type": "message",
+            "group": group_name,
+            "data": {
+                "message": "html_snippet",
+            },
+        },
+    )
+
+    assert await communicator.receive_nothing() is True
+
+    # Close
+    await communicator.disconnect()

tests/test_tags.py

@@ -113,7 +113,7 @@ def test_string(self):
         output = render(template, {}).strip()
         assert (
             output
-            == '<turbo-cable-stream-source channel="TurboStreamsChannel" signed-stream-name="test:1DyYXz2Y_VbgIPXC1AQ0ZGHhAx71uaZ36r4DFwXDaiU"></turbo-cable-stream-source>'
+            == '<turbo-cable-stream-source channel="TurboStreamCableChannel" signed-stream-name="test:1DyYXz2Y_VbgIPXC1AQ0ZGHhAx71uaZ36r4DFwXDaiU"></turbo-cable-stream-source>'
         )
 
     def test_dom_id_variable(self):
@@ -125,5 +125,5 @@ def test_dom_id_variable(self):
         output = render(template, {"dom_id": "todo_3"}).strip()
         assert (
             output
-            == '<turbo-cable-stream-source channel="TurboStreamsChannel" signed-stream-name="test_todo_3:7ZS0MxQWhRTCAnG3olGO9AJKfvos3iaHGoBMBt8ZbSM"></turbo-cable-stream-source>'
+            == '<turbo-cable-stream-source channel="TurboStreamCableChannel" signed-stream-name="test_todo_3:7ZS0MxQWhRTCAnG3olGO9AJKfvos3iaHGoBMBt8ZbSM"></turbo-cable-stream-source>'
         )

tox.ini

@@ -9,6 +9,10 @@ deps =
     django32: django>=3.2,<3.3
     django42: django>=3.3,<4.3
     channels
+    daphne
+    pytest-asyncio
+    channels_redis
+    django-actioncable
     typing_extensions
     pytest
     pytest-django