Watch a web page for edits with IFTTT and urlwatch

README.md

This setup allows to trigger an IFTTT event whenever a web page changes. It uses the urlwatch utility and the IFTTT Maker Channel.

Instructions:

• Sign up to IFTTT.
• Connect IFTTT's Maker Channel, and take note of your Maker key.
• Create a new Recipe that takes the Maker Channel as input and outputs wherever you want. I used IF Notifications with the IF Android app, so that I get a notification on my phone whenever the trigger runs. The script passes the updated URL to IFTTT as value1, and my notification contains URL updated: {{Value1}}, so that I know which of the web pages has been updated.
• On the machine that will check the website for changes install urlwatch and python2-requests.
• Echo the URLs to check to ~/.urlwatch/urls.txt, one per line.
• Then, copy over my hooks.py to ~/.urlwatch/libs/hooks.py adding the URLs to the ifttt_urls tuple and substituting YOUR_TRIGGER_NAME and YOUR_MAKER_KEY.
• Finally launch crontab -e and set up a cron job to run urlwatch at the frequency you prefer. For example, to have it running every 30 minutes, add a line containing: */30 * * * * urlwatch.

hooks.py

#! /usr/bin/env python2

import hashlib
import os
from requests import post
from urlwatch import html2txt
from urlwatch.handler import JobBase

def filter(url, data):
    # URLs that will trigger an IFTTT notification
    ifttt_urls = (
        'FIRST_URL',
        'SECOND_URL',
        'THIRD_URL',
        # ...and so on
    )
    if url in ifttt_urls:
        # Strip html tags (optional) and compute the cache file name
        data = html2txt.html2text(data, method='re')
        cache_file = os.path.join(os.path.expanduser('~'), '.urlwatch/cache', JobBase(url).get_guid())

        # Don't try comparison if there is no cache file yet
        if os.path.isfile(cache_file):
            # Hash the data and the cache file
            data_hash = hashlib.md5(data).hexdigest()
            cache_hash = hashlib.md5(open(cache_file, 'rb').read()).hexdigest()

            # If hashes differ, trigger a notification on IFTTT
            if data_hash != cache_hash:
                post('https://maker.ifttt.com/trigger/YOUR_TRIGGER_NAME/with/key/YOUR_MAKER_KEY', data={'value1':url})

        return data

    # Catch all
    return data

Thanks, this works great! One minor typo report that took me a few minutes of head-scratching to figure out: ~/.urlwatch/libs/hooks.py should instead be ~/.urlwatch/lib/hooks.py (lib not libs). At least that's how it works for my version of urlwatch.

I guess it doesn't work with urlwatch2 ? Seeing as it's python3 based...