Drop channels and custom subscriptions support

Author: zerolab

.github/workflows/ci.yml

@@ -68,27 +68,3 @@ jobs:
           cd tests
           python manage.py migrate
           python manage.py test
-
-  test_channels:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
-        with:
-          python-version: 3.8
-          cache: 'pip'
-          cache-dependency-path: |
-            tests/requirements-channels.txt
-
-      - name: Install Dependencies
-        run: |
-          cd tests
-          python -m pip install --upgrade pip
-          python -m pip install -r requirements-channels.txt
-
-      - name: Run Tests
-        run: |
-          cd tests
-          python manage.py migrate
-          python manage.py test

Dockerfile

@@ -20,13 +20,12 @@ COPY ./setup.py ./code/setup.py
 
 # copy example site requires file
 COPY ./tests/requirements.txt /code/tests/requirements.txt
-COPY ./tests/requirements-channels.txt /code/tests/requirements-channels.txt
 
 WORKDIR /code/tests
 
 RUN pip install --upgrade pip
 # Install any needed packages specified in requirements.txt
-RUN pip install -r ./requirements-channels.txt
+RUN pip install -r ./requirements.txt
 RUN pip install gunicorn
 
 # Copy the current directory contents into the container at /code/

README.md

@@ -19,8 +19,6 @@ A library to build GraphQL endpoints easily so you can grapple your Wagtail data
 
 ## About The Project
 
-![GraphQL Preview Demo](docs/demo.gif)
-
 There is a range of GraphQL packages for Python and specifically Django.
 However, getting these packages to work out of the box with an existing infrastructure
 without errors isn't as easy to come by.
@@ -35,28 +33,24 @@ to your model and away you go (although if you want to go deeper you can!).
 
 -   Easily create GraphQL types by adding a small annotation in your models.
 -   Supports traditional Wagtail models:
-    -   Pages (including Streamfield & Orderables)
+    -   Pages (including StreamField & Orderables)
     -   Snippets
     -   Images
     -   Documents
-    -   Media
+    -   Media (via [wagtailmedia](https://pypi.org/project/wagtailmedia/))
     -   Settings
     -   Redirects
     -   Search (on all models)
 -   Custom Image & Document model support
 -   Pagination support
 -   Middleware support
--   Advanced headless preview functionality built using GraphQL Subscriptions to enable Page previews on any device!
 
 ### Built With
 
 This library is an abstraction upon and relies heavily on Graphene & Graphene Django.
-We also use Django Channels and the Potrace image library.
 
 -   [Graphene](https://github.com/graphql-python/graphene)
 -   [Graphene Django](https://github.com/graphql-python/graphene)
--   [Potrace](https://github.com/skyrpex/potrace)
--   [Django Channels](https://github.com/django/channels) when installed with `wagtail_grapple[channels]`
 
 ## Getting Started
 
@@ -65,7 +59,7 @@ Getting Grapple installed is designed to be as simple as possible!
 ### Prerequisites
 
 ```
-Python>=3.8,<3.12
+Python >= 3.8
 Wagtail >= 4.1
 ```
 
@@ -88,19 +82,6 @@ INSTALLED_APPS = [
 ]
 ```
 
-For GraphQL Subscriptions with Django Channels, run `pip install wagtail_grapple[channels]` and add
-`channels` to installed apps:
-
-```python
-INSTALLED_APPS = [
-    # ...
-    "grapple",
-    "graphene_django",
-    "channels",
-    # ...
-]
-```
-
 Add the following to the bottom of the same settings file, where each key is the app you want to this library to scan and the value is the prefix you want to give to GraphQL types (you can usually leave this blank):
 
 ```python
@@ -114,6 +95,7 @@ GRAPPLE = {
 Add the GraphQL URLs to your `urls.py`:
 
 ```python
+from django.urls import include, path
 from grapple import urls as grapple_urls
 
 # ...

docs/general-usage/hooks.rst

@@ -90,8 +90,10 @@ Grapple provides a ``register_schema_mutation`` hook that is called when it crea
 Subscription
 ^^^^^^^^^^^^
 
-Note: subscriptions are only enabled when Grapple is installed with Django Channels: ``pip install wagtail_grapple[channels]``.
-Grapple provides a ``register_schema_subscription`` hook that is called when it creates the schema. You can use it to add your custom ``Subscription`` mixins
+Note: previously subscriptions were only enabled when Grapple was installed with Django Channels. We no longer provide
+out of the box support for subscriptions due to incompatibilities in the various dependencies.
+The ``register_schema_subscription`` hook is still provided. It is called when Grapple creates the schema.
+You can use it to add your custom ``Subscription`` mixins and functionality.
 
 .. code-block:: python
     import asyncio

docs/general-usage/preview.rst

@@ -6,114 +6,5 @@ Grapple also provides support for headless previews using the `Wagtail Headless
 This means you can pass a unique 'preview token' to the GraphQL endpoint and preview a page as you update
 it in the admin (in real-time!).
 
-Grapple's Headless Preview is built-on GraphQL Subscriptions which means
-that your client subscribes to the preview page and any changes in the Admin
-will be pushed to your client via WebSockets. This allows you to add preview
-support to any client whether that be a SPA or Native App.
-
-Setup
-^^^^^
-
-See :ref:`usage with subscriptions<usage-with-subscriptions>` first to make sure you installed Django Channels when you installed Grapple.
-Your installed apps in your settings should look like so:
-
-.. code-block:: python
-
-    INSTALLED_APPS = [
-        # ...
-        "grapple",
-        "graphene_django",
-        "channels",
-        "wagtail_headless_preview",
-        # ...
-    ]
-
-Now you need to run the migrations that come with Wagtail Headless Preview.
-
-::
-
-   $ python manage.py migrate
-
-
-
-You also want to add to your settings the URL you want to redirect to when the
-user clicks the 'Preview' button:
-
-.. code-block:: python
-
-    HEADLESS_PREVIEW_CLIENT_URLS = {
-        "default": "http://localhost:8001/preview",
-    }
-
-    HEADLESS_PREVIEW_LIVE = True
-
-Two HTTP params are also passed to this url:
- - ``content_type``: The content type string of the Model you're viewing.
- - ``token``: The preview token you need to retrieve the preview data.
-
-*Attention*: When the user clicks the "Preview" or "View Draft" button in the Wagtail admin the preview opens in a new tab. The URL in the preview tab will not reveal the actual preview URL set in the setting. It will rather show the admin URL of the page with an additional URL element ``/preview`` or ``/view_draft`` (e.g. ``http://localhost:8000/admin/pages/5/edit/preview/``).
-
-
-Your next step is to subclass any Page models you want headless preview on with
-``wagtail_headless_preview.models.HeadlessPreviewMixin`` to override the original Wagtail preview methods:
-
-.. code-block:: python
-
-    from wagtail_headless_preview.models import HeadlessPreviewMixin
-
-
-    class BlogPage(HeadlessPreviewMixin, Page):
-        author = models.CharField(max_length=255)
-        date = models.DateField("Post date")
-        advert = models.ForeignKey(
-            "home.Advert",
-            null=True,
-            blank=True,
-            on_delete=models.SET_NULL,
-            related_name="+",
-        )
-
-
-And you are done!
-
-
-How to use
-^^^^^^^^^^
-
-Now when you click the 'Preview' button in Wagtail a page will open with the content of
-your defined `HEADLESS_PREVIEW_CLIENT_URLS`. You can either load the preview token through
-the HTTP params or through the ``used-token`` cookie which has been set in
-both the Admin and the redirected page.
-
-Once you've pushed the 'Preview' button, Any data input into the Admin form
-will be pushed to your subscribed client. Pushing the button again will start
-a new session with a new token.
-
-To access the preview data you can use one of the three queries (the 'subscription'
-declaration is optional if you want to do a one time query):
-
-::
-
-    subscription {
-        page(contentType: "home.blogpage", token: "id=4:1hg5FZ:bPmOihaRCLGbo4mzZagvrJAqNWM") {
-            title
-        }
-    }
-
-
-::
-
-    subscription {
-        page(slug: "example-blog-page", token: "id=4:1hg5FZ:bPmOihaRCLGbo4mzZagvrJAqNWM") {
-            title
-        }
-    }
-
-
-::
-
-    subscription {
-        page(id: 1, token: "id=4:1hg5FZ:bPmOihaRCLGbo4mzZagvrJAqNWM") {
-            title
-        }
-    }
+See the `Wagtail Headless Preview<https://github.com/torchbox/wagtail-headless-preview>`_ documentation for setup
+instructions.

docs/getting-started/installation.rst

@@ -58,26 +58,3 @@ By default, Grapple uses :doc:`these settings <../general-usage/settings>`.
 
 
 *Your GraphQL endpoint is available at http://localhost:8000/graphql/*
-
- .. _usage-with-subscriptions:
-Usage with subscriptions
-========================
-
-To enable GraphQL Subscriptions, you need to install Grapple with Django Channels.
-Run ``pip install wagtail_grapple[channels]`` and add ``channels`` to installed apps:
-
-.. code-block:: python
-
-    INSTALLED_APPS = [
-        # ...
-        "grapple",
-        "graphene_django",
-        "channels",
-        # ...
-    ]
-
-Add the following Django Channels configuration to your settings.
-
-.. code-block:: python
-
-    ASGI_APPLICATION = "graphql_ws.django.routing.application"

grapple/schema.py

@@ -12,8 +12,8 @@
 # to be a nice way to disable this validator so we monkey-patch it instead.
 
 
-# We can't simply override specified_rules because it's a tuple and immutable. Instead we are
-# monkey patching the NoUnusedFragmentRule.leave_document so it doesn't do any validation.
+# We can't simply override specified_rules because it's a tuple and immutable. Instead, we are
+# monkey patching the NoUnusedFragmentRule.leave_document, so it doesn't do any validation.
 NoUnusedFragmentsRule.leave_document = lambda self, *_args: None
 
 
@@ -23,8 +23,6 @@ def create_schema():
     It inherits its queries from each of the specific type mixins.
     """
 
-    from .settings import has_channels
-
     query_mixins = []
     for fn in hooks.get_hooks("register_schema_query"):
         fn(query_mixins)
@@ -40,34 +38,28 @@ class Query(*query_mixins):
     for fn in hooks.get_hooks("register_schema_mutation"):
         fn(mutation_mixins)
 
-    # ensure graphene.ObjectType is always present
-    if graphene.ObjectType not in mutation_mixins:
-        mutation_mixins.append(graphene.ObjectType)
-
-    if len(mutation_mixins) > 1:
+    if len(mutation_mixins) > 0:
+        # ensure graphene.ObjectType is always present
+        if graphene.ObjectType not in mutation_mixins:
+            mutation_mixins.append(graphene.ObjectType)
 
         class Mutation(*mutation_mixins):
             pass
 
     else:
         Mutation = None
 
-    if has_channels:
-        subscription_mixins = []
-        for fn in hooks.get_hooks("register_schema_subscription"):
-            fn(subscription_mixins)
+    subscription_mixins = []
+    for fn in hooks.get_hooks("register_schema_subscription"):
+        fn(subscription_mixins)
 
+    if len(subscription_mixins) > 0:
         # ensure graphene.ObjectType is always present
         if graphene.ObjectType not in subscription_mixins:
             subscription_mixins.append(graphene.ObjectType)
 
-        if len(subscription_mixins) > 1:
-
-            class Subscription(*subscription_mixins):
-                pass
-
-        else:
-            Subscription = None
+        class Subscription(*subscription_mixins):
+            pass
 
     else:
         Subscription = None

grapple/settings.py

@@ -16,13 +16,6 @@
 
 logger = logging.getLogger("grapple")
 
-try:
-    import channels  # noqa: F401
-
-    has_channels = True
-except ImportError:
-    has_channels = False
-
 
 DEFAULTS = {
     "APPS": [],