code-boxx/0-PY-PUSH.MD

## 0-PY-PUSH.MD

      
    Raw
  

              0-PY-PUSH.MD
            
          
    PYTHON FLASK PUSH NOTIFICATIONS

https://code-boxx.com/python-flask-push-notifications/
NOTES


Run unpack.bat (Windows) unpack.sh (Linux/Mac). This will automatically:

Create a templates folder, move S2_perm_sw.html inside.
Create a static folder, move S3_sw.js inside.
Save the below images as static/i-banner.png and static/i-ico.png
Create a virtual environment - virtualenv venv.
Activate the virtual environment - venv\scripts\activate (Windows) venv/bin/activate (Mac/Linux)
Install required modules - pip install flask ecdsa pywebpush
Run python S1_vapid.py to generate the VAPID keys.


Copy the public key into templates/S2_perm_sw.html - const publicKey, and the private key into templates/S4_server.py - VAPID_PRIVATE.
Run python S4_server.py, access http://localhost in your browser and allow notifications.

IMAGES


LICENSE

Copyright by Code Boxx
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

  
## S1_vapid.py
# (A) REQUIRED MODULES
import base64
import ecdsa

# (B) GENERATE KEYS
# CREDITS : https://gist.github.com/cjies/cc014d55976db80f610cd94ccb2ab21e
pri = ecdsa.SigningKey.generate(curve=ecdsa.NIST256p)
pub = pri.get_verifying_key()
keys = {
  "private" : base64.urlsafe_b64encode(pri.to_string()).decode("utf-8").strip("="),
  "public" : base64.urlsafe_b64encode(b"\x04" + pub.to_string()).decode("utf-8").strip("=")
}
print(keys)

## S2_perm_sw.html
<!DOCTYPE html>
<html>
  <head>
    <title>Push Notification</title>
    <meta charset="utf-8">
  </head>
  <body>
    <script>
    // (A) OBTAIN USER PERMISSION TO SHOW NOTIFICATION
    window.onload = () => {
      // (A1) ASK FOR PERMISSION
      if (Notification.permission === "default") {
        Notification.requestPermission().then(perm => {
          if (Notification.permission === "granted") {
            regWorker().catch(err => console.error(err));
          } else {
            alert("Please allow notifications.");
          }
        });
      }

      // (A2) GRANTED
      else if (Notification.permission === "granted") {
        regWorker().catch(err => console.error(err));
      }

      // (A3) DENIED
      else { alert("Please allow notifications."); }
    }

    // (B) REGISTER SERVICE WORKER
    async function regWorker () {
      // (B1) YOUR PUBLIC KEY - CHANGE TO YOUR OWN!
      const publicKey = "YOUR-PUBLIC-KEY";

      // (B2) REGISTER SERVICE WORKER
      navigator.serviceWorker.register("S3_sw.js", { scope: "/" });

      // (B3) SUBSCRIBE TO PUSH SERVER
      navigator.serviceWorker.ready
      .then(reg => {
        reg.pushManager.subscribe({
          userVisibleOnly: true,
          applicationServerKey: publicKey
        }).then(
          // (B3-1) OK - TEST PUSH NOTIFICATION
          sub => {
            var data = new FormData();
            data.append("sub", JSON.stringify(sub));
            fetch("/push", { method:"POST", body:data })
            .then(res => res.text())
            .then(txt => console.log(txt))
            .catch(err => console.error(err));
          },

          // (B3-2) ERROR!
          err => console.error(err)
        );
      });
    }
    </script>
  </body>
</html>

## S3_sw.js
// (A) INSTANT WORKER ACTIVATION
self.addEventListener("install", evt => self.skipWaiting());

// (B) CLAIM CONTROL INSTANTLY
self.addEventListener("activate", evt => self.clients.claim());

// (C) LISTEN TO PUSH
self.addEventListener("push", evt => {
  const data = evt.data.json();
  self.registration.showNotification(data.title, {
    body: data.body,
    icon: data.icon,
    image: data.image
  });
});

## S4_server.py
# (A) INIT
# (A1) LOAD MODULES
from flask import Flask, render_template, request, make_response, send_from_directory
from pywebpush import webpush, WebPushException
import json

# (A2) FLASK SETTINGS + INIT - CHANGE TO YOUR OWN!
HOST_NAME = "localhost"
HOST_PORT = 80
VAPID_SUBJECT = "mailto:your@email.com"
VAPID_PRIVATE = "YOUR-PRIVATE-KEY"
app = Flask(__name__)
# app.debug = True

# (B) VIEWS
# (B1) "LANDING PAGE"
@app.route("/")
def index():
  return render_template("S2_perm_sw.html")

# (B2) SERVICE WORKER
@app.route("/S3_sw.js")
def sw():
  response = make_response(send_from_directory(app.static_folder, "S3_sw.js"))
  return response

# (B3) PUSH DEMO
@app.route("/push", methods=["POST"])
def push():
  # (B3-1) GET SUBSCRIBER
  sub = json.loads(request.form["sub"])

  # (B3-2) TEST PUSH NOTIFICATION
  result = "OK"
  try:
    webpush(
      subscription_info = sub,
      data = json.dumps({
        "title" : "Welcome!",
        "body" : "Yes, it works!",
        "icon" : "static/i-ico.png",
        "image" : "static/i-banner.png"
      }),
      vapid_private_key = VAPID_PRIVATE,
      vapid_claims = { "sub": VAPID_SUBJECT }
    )
  except WebPushException as ex:
    print(ex)
    result = "FAILED"
  return result

# (C) START
if __name__ == "__main__":
  app.run(HOST_NAME, HOST_PORT)

## unpack.bat
md templates
md static
move S2_perm_sw.html templates
move S3_sw.js static
curl https://user-images.githubusercontent.com/11156244/281081281-a7385905-0a84-4053-b19d-9584f7ba017d.png --ssl-no-revoke --output static/i-banner.png
curl https://user-images.githubusercontent.com/11156244/281081294-9878c258-0609-4da6-8abf-e855635651b2.png --ssl-no-revoke --output static/i-ico.png
virtualenv venv
call venv\Scripts\activate
pip install flask ecdsa pywebpush
python S1_vapid.py

## unpack.sh
mkdir -m 777 templates
mkdir -m 777 static
mv ./S2_perm_sw.html ./templates
mv ./S3_sw.js ./static
curl https://user-images.githubusercontent.com/11156244/281081281-a7385905-0a84-4053-b19d-9584f7ba017d.png --ssl-no-revoke --output ./static/i-banner.png
curl https://user-images.githubusercontent.com/11156244/281081294-9878c258-0609-4da6-8abf-e855635651b2.png --ssl-no-revoke --output ./static/i-ico.png
virtualenv venv
source "venv/bin/activate"
pip install flask ecdsa pywebpush
python S1_vapid.py
	# (A) REQUIRED MODULES
	import base64
	import ecdsa

	# (B) GENERATE KEYS
	# CREDITS : https://gist.github.com/cjies/cc014d55976db80f610cd94ccb2ab21e
	pri = ecdsa.SigningKey.generate(curve=ecdsa.NIST256p)
	pub = pri.get_verifying_key()
	keys = {
	"private" : base64.urlsafe_b64encode(pri.to_string()).decode("utf-8").strip("="),
	"public" : base64.urlsafe_b64encode(b"\x04" + pub.to_string()).decode("utf-8").strip("=")
	}
	print(keys)
	<!DOCTYPE html>
	<html>
	<head>
	<title>Push Notification</title>
	<meta charset="utf-8">
	</head>
	<body>
	<script>
	// (A) OBTAIN USER PERMISSION TO SHOW NOTIFICATION
	window.onload = () => {
	// (A1) ASK FOR PERMISSION
	if (Notification.permission === "default") {
	Notification.requestPermission().then(perm => {
	if (Notification.permission === "granted") {
	regWorker().catch(err => console.error(err));
	} else {
	alert("Please allow notifications.");
	}
	});
	}

	// (A2) GRANTED
	else if (Notification.permission === "granted") {
	regWorker().catch(err => console.error(err));
	}

	// (A3) DENIED
	else { alert("Please allow notifications."); }
	}

	// (B) REGISTER SERVICE WORKER
	async function regWorker () {
	// (B1) YOUR PUBLIC KEY - CHANGE TO YOUR OWN!
	const publicKey = "YOUR-PUBLIC-KEY";

	// (B2) REGISTER SERVICE WORKER
	navigator.serviceWorker.register("S3_sw.js", { scope: "/" });

	// (B3) SUBSCRIBE TO PUSH SERVER
	navigator.serviceWorker.ready
	.then(reg => {
	reg.pushManager.subscribe({
	userVisibleOnly: true,
	applicationServerKey: publicKey
	}).then(
	// (B3-1) OK - TEST PUSH NOTIFICATION
	sub => {
	var data = new FormData();
	data.append("sub", JSON.stringify(sub));
	fetch("/push", { method:"POST", body:data })
	.then(res => res.text())
	.then(txt => console.log(txt))
	.catch(err => console.error(err));
	},

	// (B3-2) ERROR!
	err => console.error(err)
	);
	});
	}
	</script>
	</body>
	</html>
	// (A) INSTANT WORKER ACTIVATION
	self.addEventListener("install", evt => self.skipWaiting());

	// (B) CLAIM CONTROL INSTANTLY
	self.addEventListener("activate", evt => self.clients.claim());

	// (C) LISTEN TO PUSH
	self.addEventListener("push", evt => {
	const data = evt.data.json();
	self.registration.showNotification(data.title, {
	body: data.body,
	icon: data.icon,
	image: data.image
	});
	});
	# (A) INIT
	# (A1) LOAD MODULES
	from flask import Flask, render_template, request, make_response, send_from_directory
	from pywebpush import webpush, WebPushException
	import json

	# (A2) FLASK SETTINGS + INIT - CHANGE TO YOUR OWN!
	HOST_NAME = "localhost"
	HOST_PORT = 80
	VAPID_SUBJECT = "mailto:your@email.com"
	VAPID_PRIVATE = "YOUR-PRIVATE-KEY"
	app = Flask(__name__)
	# app.debug = True

	# (B) VIEWS
	# (B1) "LANDING PAGE"
	@app.route("/")
	def index():
	return render_template("S2_perm_sw.html")

	# (B2) SERVICE WORKER
	@app.route("/S3_sw.js")
	def sw():
	response = make_response(send_from_directory(app.static_folder, "S3_sw.js"))
	return response

	# (B3) PUSH DEMO
	@app.route("/push", methods=["POST"])
	def push():
	# (B3-1) GET SUBSCRIBER
	sub = json.loads(request.form["sub"])

	# (B3-2) TEST PUSH NOTIFICATION
	result = "OK"
	try:
	webpush(
	subscription_info = sub,
	data = json.dumps({
	"title" : "Welcome!",
	"body" : "Yes, it works!",
	"icon" : "static/i-ico.png",
	"image" : "static/i-banner.png"
	}),
	vapid_private_key = VAPID_PRIVATE,
	vapid_claims = { "sub": VAPID_SUBJECT }
	)
	except WebPushException as ex:
	print(ex)
	result = "FAILED"
	return result

	# (C) START
	if __name__ == "__main__":
	app.run(HOST_NAME, HOST_PORT)
	md templates
	md static
	move S2_perm_sw.html templates
	move S3_sw.js static
	curl https://user-images.githubusercontent.com/11156244/281081281-a7385905-0a84-4053-b19d-9584f7ba017d.png --ssl-no-revoke --output static/i-banner.png
	curl https://user-images.githubusercontent.com/11156244/281081294-9878c258-0609-4da6-8abf-e855635651b2.png --ssl-no-revoke --output static/i-ico.png
	virtualenv venv
	call venv\Scripts\activate
	pip install flask ecdsa pywebpush
	python S1_vapid.py
	mkdir -m 777 templates
	mkdir -m 777 static
	mv ./S2_perm_sw.html ./templates
	mv ./S3_sw.js ./static
	curl https://user-images.githubusercontent.com/11156244/281081281-a7385905-0a84-4053-b19d-9584f7ba017d.png --ssl-no-revoke --output ./static/i-banner.png
	curl https://user-images.githubusercontent.com/11156244/281081294-9878c258-0609-4da6-8abf-e855635651b2.png --ssl-no-revoke --output ./static/i-ico.png
	virtualenv venv
	source "venv/bin/activate"
	pip install flask ecdsa pywebpush
	python S1_vapid.py