EDIT for Mission Clarity: In the end I am pulling inventory data and customer data from Postgres to render and send a bunch of PDFs to customers, once per month. These PDFs are dynamic in that the cover page will have varying customer name/address. The next page(s) are also dynamic as they are lists of a particular customer's expiring inventory with item/expirying date/serial number.
I had made a client-side React page with print CSS to render some print-layout letters that could be printed off/saved as a pretty PDF.
Then, the waterfall spec came in that this was to be an automated process on the server. Basically, the PDF needs attached to an email alerting customers of expiring product (in med industry where everything needs audited).
I thought using Puppeteer would be a nice and easy switch. Just add a route that processes all customers, looking up whatever may be expiring, and then passing that into the dynamic react page to be rendered headless to a PDF file (and eventually finish the whole rest of the plan, sending email, etc.). Right now I just grab 10 customers and their expiring stock for PoC, then I have basically: { customer: {}, expiring: [] }.
I've attempted using POST to page with interrupt, but I guess that makes sense that I cannot get post data in the browser. So, I switched my approach to using cookies. This I would expect to work, but I can never read the cookie(s) into the page.
Here is a: Simple route, simple puppeteer which writes out cookies to a json and takes a screenshot just for proof, and simple HTML with script I'm using just to try to prove I can pass data along.
server/index.js:
app.get('/testing', async (req, res) => {
console.log('GET /testing');
res.sendFile(path.join(__dirname, 'scratch.html'));
});
scratch.js (run at commandline node ./scratch.js:
const puppeteer = require('puppeteer')
const fs = require('fs');
const myCookies = [{name: 'customer', value: 'Frank'}, {name: 'expiring', value: JSON.stringify([{a: 1, b: 'three'}])}];
(async () => {
const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.goto('http://localhost:1234/testing', { waitUntil: 'networkidle2' });
await page.setCookie(...myCookies);
const cookies = await page.cookies();
const cookieJson = JSON.stringify(cookies);
// Writes expected cookies to file for sanity check.
fs.writeFileSync('scratch_cookies.json', cookieJson);
// FIXME: Cookies never get appended to page.
await page.screenshot({path: 'scratch_shot.png'});
await browser.close();
})();
server/scratch.html:
<html>
<body>
</body>
<script type='text/javascript'>
document.write('Cookie: ' + document.cookie);
</script>
</html>
The result is just a PNG with the word "Cookie:" on it. Any insight appreciated!
This is the actual route I'm using where makeExpiryLetter is utilizing puppeteer, but I can't seem to get it to actually read the customer and rows data.
app.get('/create-expiry-letter', async (req, res) => {
// Create PDF file using puppeteer to render React page w/ data.
// Store in Db.
// Email file.
// Send final count of letters sent back for notification in GUI.
const cc = await dbo.getConsignmentCustomers();
const result = await Promise.all(cc.rows.map(async x => {
// Get 0-60 day consignments by customer_id;
const { rows } = await dbo.getExpiry0to60(x.customer_id);
if (rows && rows.length > 0) {
const epiryLetter = await makeExpiryLetter(x, rows); // Uses puppeteer.
// TODO: Store in Db / Email file.
return true;
} else {
return false;
}
}));
res.json({ emails_sent: result.filter(x => x === true).length });
});
Thanks to the samples from @ggorlen I've made huge headway in using cookies. In my inline script of expiry.html I'm grabbing the values by wrapping my render function in function main () and adding onload to body tag <body onload='main()'.
Inside the main function we can grab the values I needed:
const customer = JSON.parse(document.cookie.split('; ').find(row => row.startsWith('customer')).split('=')[1]);
const expiring = JSON.parse(document.cookie.split('; ').find(row => row.startsWith('expiring')).split('=')[1]);
FINALLY (and yes, of course this will all be used in an automated worker in the end) I can get my beautifully rendered PDF like so:
(async () => {
const browser = await puppeteer.launch();
const [page] = await browser.pages();
await page.setCookie(...myCookies);
await page.goto('http://localhost:1234/testing');
await page.pdf({ path: `scratch-expiry-letter.pdf`, format: 'letter' });
await browser.close();
})();
