Push Packt Free Book of the Day alert into your slack channel

_readme.md

Push alerts about the daily 🆓 Packt eBook into Slack

Install this globally. Yes, globally.

$ npm install -g scrape-html

Now create a local project somewhere:

$ cd free_the_books
$ npm init
$ npm install --save node-slack scrape-html

Copy in index.js from below and fill in your slack webhook config. Schedule it to run with cron:

$ crontab -e

I have mine setup to run at 9am, which looks like the following. If you need help learning cron snytax I like http://crontab.guru

0 9 * * * /usr/local/bin/node /Users/atcodes/DEV/free_the_books/index.js

For non-default node-global-install-location people:

By default node wants to install globals into /usr/local/lib/node_modules/ (and this is why you probably have to sudo every time you install a global). If you've wisely changed your default install location, this is how you adjust for it:

Your crontab line will need to set the environment variable NODE_PATH before executing the program. Change it to look like the following:

0 9 * * * NODE_PATH=NODE_PATH=/Users/atcodes/.npm_globals/lib/node_modules/scrape-html/node_modules/ /usr/local/bin/node /Users/atcodes/DEV/free_the_books/index.js

Note that in the example above, my username is atcodes and I install node globals to ~/.npm_globals/

index.js

const Slack = require( 'node-slack' );
const scrape = require( 'scrape-html' );
const listing = 'https://www.packtpub.com/packt/offers/free-learning';

let slackConfig = {
	webhook_url: 'https://hooks.slack.com/..............'
	,token: '{your-webhook-token-here}'
	,chan: '#general'
	,botName: 'FreeBooksBot'
};

const print = ( title, img ) => {
	const slack = new Slack( slackConfig.webhook_url );
	const message = `Today's :free: eBook from Packt is: *${title}*\n${img}\n\nGet it now: ${listing}`;

	slack.send( {
		text: message
		,channel: '@atuttle'
		,username: 'FreeBooksBot'
	}
	,( err ) => {
		if ( err ) {
			return console.error( err );
		}
	} );
};

const titleSelector = '.dotd-title h2';
const imgSelector = '.dotd-main-book-image img';
const handler = ( err, window ) => {
	const title = window.$( titleSelector )[0].innerHTML.trim();
	const img = 'https:' + window.$( imgSelector ).data( 'original' ).trim();
	print( title, img );
};

scrape( listing, titleSelector, handler );