Email facebook login

Here is an example of an email-based Facebook login flow:

Step 1: User requests login

The user clicks on the "Login with Facebook" button on your website or app.

Step 2: Redirect to Facebook login page

Your website or app redirects the user to the Facebook login page, which is typically in the format of https://www.facebook.com/v3.3/dialog/oauth?client_id=YOUR_APP_ID&redirect_uri=YOUR_REDIRECT_URI&scope=EMAIL.

Step 3: User enters Facebook credentials

The user enters their Facebook login credentials (email and password) on the Facebook login page.

Step 4: Facebook authenticates user

Facebook authenticates the user's credentials and redirects them back to your website or app with an authorization code.

Step 5: Exchange authorization code for access token

Your website or app receives the authorization code and exchanges it for an access token by sending a POST request to https://graph.facebook.com/v3.3/oauth/access_token?client_id=YOUR_APP_ID&redirect_uri=YOUR_REDIRECT_URI&code=AUTHORIZATION_CODE.

Step 6: Use access token to retrieve user's email

Your website or app uses the access token to retrieve the user's email address by sending a GET request to https://graph.facebook.com/v3.3/me?access_token=ACCESS_TOKEN.

Step 7: Verify user's email

Your website or app verifies the user's email address to ensure it matches the email address associated with their Facebook account.

Step 8: Grant access

If the email address is verified, your website or app grants access to the user's account and allows them to log in.

Here is an example of the email-based Facebook login flow in code:

import requests

# Step 1: Redirect to Facebook login page
redirect_url = 'https://www.facebook.com/v3.3/dialog/oauth?client_id=YOUR_APP_ID&redirect_uri=YOUR_REDIRECT_URI&scope=EMAIL'
webbrowser.open(redirect_url)

# Step 4: Exchange authorization code for access token
authorization_code = 'AUTHORIZATION_CODE'
access_token_url = 'https://graph.facebook.com/v3.3/oauth/access_token'
access_token_params = {
    'client_id': 'YOUR_APP_ID',
    'redirect_uri': 'YOUR_REDIRECT_URI',
    'code': authorization_code
}
response = requests.post(access_token_url, params=access_token_params)
access_token = response.json()['access_token']

# Step 6: Retrieve user's email
me_url = 'https://graph.facebook.com/v3.3/me'
me_params = {
    'access_token': access_token
}
response = requests.get(me_url, params=me_params)
user_email = response.json()['email']

# Step 7: Verify user's email
if user_email == 'USER_EMAIL':
    # Grant access
    print('User logged in successfully!')
else:
    print('Invalid email address')

Note that this is just an example and you should modify the code to fit your specific use case. Additionally, you should handle errors and exceptions properly to ensure a smooth user experience.