Add push notification example

push-notification/.gitignore

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+assets/external/
+.web
+*.py[cod]
+__pycache__/
+*.db
+applicationServerKey
+private_key.pem
+public_key.pem

push-notification/README.md

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+# push-notification
+
+Send Web Push API notifications from a Reflex app!
+
+## Setup
+
+```
+pip install -r requirements.txt
+reflex db migrate  # create database of subscribers
+vapid-gen          # generate keys
+```
+
+## Code Overview
+
+### Python
+
+* `push_notification.py` - main entry point and UI for Reflex app
+* `state.py` - Reflex state for sending notifications and interacting with the database
+* `models.py` - database model for storing subscription data and notification fields
+* `register.py` - backend route for receiving subscription data from frontend
+* `push.py` - routines for sending push notifications from the backend
+
+### JavaScript
+
+* `assets/sw.js` - service worker to be registered in the browser
+* `assets/push.js` - script to request permission and send subscription data to backend
+
+## Further Reading
+
+Did you know your server can send web push notifications to your app _for free_, without subscribing to some third party push service?
+
+**Check out the [Web Push Book](https://web-push-book.gauntface.com) for a deep dive into the Web Push API and how it works.**
+
+* [webpush](https://pypi.org/project/webpush/) python library used by this example code
+* [MDN Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) docs

push-notification/alembic.ini

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+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+# Use forward slashes (/) also on windows to provide an os agnostic path
+script_location = alembic
+
+# template used to generate migration file names; The default value is %%(rev)s_%%(slug)s
+# Uncomment the line below if you want the files to be prepended with date and time
+# see https://alembic.sqlalchemy.org/en/latest/tutorial.html#editing-the-ini-file
+# for all available tokens
+# file_template = %%(year)d_%%(month).2d_%%(day).2d_%%(hour).2d%%(minute).2d-%%(rev)s_%%(slug)s
+
+# sys.path path, will be prepended to sys.path if present.
+# defaults to the current working directory.
+prepend_sys_path = .
+
+# timezone to use when rendering the date within the migration file
+# as well as the filename.
+# If specified, requires the python>=3.9 or backports.zoneinfo library.
+# Any required deps can installed by adding `alembic[tz]` to the pip requirements
+# string value is passed to ZoneInfo()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; This defaults
+# to alembic/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path.
+# The path separator used here should be the separator specified by "version_path_separator" below.
+# version_locations = %(here)s/bar:%(here)s/bat:alembic/versions
+
+# version path separator; As mentioned above, this is the character used to split
+# version_locations. The default within new alembic.ini files is "os", which uses os.pathsep.
+# If this key is omitted entirely, it falls back to the legacy behavior of splitting on spaces and/or commas.
+# Valid values for version_path_separator are:
+#
+# version_path_separator = :
+# version_path_separator = ;
+# version_path_separator = space
+version_path_separator = os  # Use os.pathsep. Default configuration used for new projects.
+
+# set to 'true' to search source files recursively
+# in each "version_locations" directory
+# new in Alembic version 1.10
+# recursive_version_locations = false
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+sqlalchemy.url = driver://user:pass@localhost/dbname
+
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks = black
+# black.type = console_scripts
+# black.entrypoint = black
+# black.options = -l 79 REVISION_SCRIPT_FILENAME
+
+# lint with attempts to fix using "ruff" - use the exec runner, execute a binary
+# hooks = ruff
+# ruff.type = exec
+# ruff.executable = %(here)s/.venv/bin/ruff
+# ruff.options = --fix REVISION_SCRIPT_FILENAME
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

push-notification/alembic/README

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+Generic single-database configuration.

push-notification/alembic/env.py

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+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+target_metadata = None
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_offline() -> None:
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        context.configure(
+            connection=connection, target_metadata=target_metadata
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

push-notification/alembic/script.py.mako

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+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision: str = ${repr(up_revision)}
+down_revision: Union[str, None] = ${repr(down_revision)}
+branch_labels: Union[str, Sequence[str], None] = ${repr(branch_labels)}
+depends_on: Union[str, Sequence[str], None] = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

push-notification/alembic/versions/abbd91ad85c4_.py

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+"""empty message
+
+Revision ID: abbd91ad85c4
+Revises: 
+Create Date: 2024-11-22 13:11:23.227016
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+import sqlmodel
+
+# revision identifiers, used by Alembic.
+revision: str = 'abbd91ad85c4'
+down_revision: Union[str, None] = None
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('subscriber',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('browser_id', sqlmodel.sql.sqltypes.AutoString(), nullable=False),
+    sa.Column('auth_key', sqlmodel.sql.sqltypes.AutoString(), nullable=False),
+    sa.Column('sub', sqlmodel.sql.sqltypes.AutoString(), nullable=False),
+    sa.Column('enabled', sa.Boolean(), nullable=False),
+    sa.PrimaryKeyConstraint('id')
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('subscriber')
+    # ### end Alembic commands ###

push-notification/assets/manifest.json

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+{
+    "name": "Push Notifications Sample App",
+    "short_name": "mmmm...push it",
+    "start_url": "./index.html",
+    "display": "standalone",
+  }

push-notification/assets/push.js

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+// Public base64 to Uint
+function urlBase64ToUint8Array(base64String) {
+  var padding = "=".repeat((4 - (base64String.length % 4)) % 4);
+  var base64 = (base64String + padding).replace(/\-/g, "+").replace(/_/g, "/");
+
+  var rawData = window.atob(base64);
+  var outputArray = new Uint8Array(rawData.length);
+
+  for (var i = 0; i < rawData.length; ++i) {
+    outputArray[i] = rawData.charCodeAt(i);
+  }
+  return outputArray;
+}
+
+// Register a Service Worker.
+function registerForPushNotifications(
+  registration_endpoint,
+  application_server_key,
+  browser_id, 
+) {
+  navigator.serviceWorker
+    .register("sw.js")
+    .then(function (registration) {
+      return navigator.serviceWorker.ready.then(function (
+        serviceWorkerRegistration
+      ) {
+        return serviceWorkerRegistration.pushManager
+          .getSubscription()
+          .then(function (subscription) {
+            // Existing subscription found.
+            if (subscription) {
+              return subscription;
+            }
+
+            // Make a new subscription.
+            return serviceWorkerRegistration.pushManager.subscribe({
+              userVisibleOnly: true,
+              applicationServerKey: urlBase64ToUint8Array(
+                application_server_key
+              ),
+            });
+          });
+      });
+    })
+    .then(function (subscription) {
+      // Send the subscription details to the server using the Fetch API.
+      fetch(registration_endpoint, {
+        method: "post",
+        headers: {
+          "Content-type": "application/json",
+          "X-Reflex-Browser-Id": browser_id,
+        },
+        body: JSON.stringify(subscription),
+      });
+    });
+}