Experiment: produce PDF with Puppeteer (#6)

This is currently only a sketch of how the final solution could look
like.

Still missing:
- [x] parameterize with filename and variables from meta.yaml
- [x] integrate into Github workflow
- [x] only generate PDF if HTML or Markdown have changed
- [ ] extract inline styles to `odata.css`?

.github/workflows/nodejs.yml

@@ -28,7 +28,7 @@ jobs:
           git config user.name ${GITHUB_ACTOR}
           git config user.email ${PUSHER_EMAIL}
           git add docs/*/*.html docs/*/*.md
-          git diff-index --quiet HEAD || git commit -m "auto-refreshed"
+          git diff-index --quiet HEAD || (npm run pdf --if-present && git add docs/*/*.pdf && git commit -m "auto-refreshed")
           git push
         env:
           PUSHER_EMAIL: ${{ github.event.pusher.email }}

lib/build-pdf.mjs

@@ -0,0 +1,4 @@
+import pdf from './pdf.js';
+import url from "url";
+
+await pdf("odata-data-aggregation-ext");

lib/pdf.js

@@ -0,0 +1,31 @@
+const puppeteer = require('puppeteer');
+const fs = require("fs");
+const url = require("url");
+const yaml = require("js-yaml");
+
+module.exports = async function(name) {
+  const meta = yaml.load(fs.readFileSync(__dirname + "/../" + name + "/meta.yaml"));
+
+  const browser = await puppeteer.launch({
+    headless: "new"
+  });
+  const page = await browser.newPage();
+  const htmlUrl = url.pathToFileURL(`${__dirname}/../docs/${name}/${name}.html`).href;
+  await page.goto(htmlUrl, {
+    waitUntil: "networkidle2",
+  });
+  await page.pdf({
+    path: `${__dirname}/../docs/${name}/${name}.pdf`,
+    format: "letter",
+    displayHeaderFooter: true,
+    headerTemplate: '<div style="font-size: 10px; width: 100%; text-align: center;">Standards Track Work Product</div>',
+    footerTemplate: `<div style="font-size: 8px; width: 90%; margin: auto; margin-top: 40px; display:flex; flex-flow:row wrap;">
+      <span style="text-align: left; width: 30%;">${meta.filename}</span>
+      <span style="text-align: center; width: 40%;">Copyright ${meta.copyright}. All Rights Reserved.</span>
+      <span style="text-align: right; width: 30%;">${meta.pubdate} - Page <span class="pageNumber"></span> of <span class="totalPages"></span>
+      </span></div>`,
+    margin: { top: 50, bottom: 60 }
+  });
+
+  await browser.close();
+}

odata-data-aggregation-ext/meta.yaml

@@ -1,5 +1,6 @@
 pagetitle: OData Extension for Data Aggregation Version 4.0
 subtitle: Committee Specification Draft 04
+filename: odata-data-aggregation-ext-csd04
 pubdate: 24 May 2023
 pubdateISO: '2023-05-24'
 copyright: © OASIS Open 2023