Next.js / purchase orders
Purchase order PDFs in Next.js
Post your purchase order HTML to a render API from a Route Handler returning a Response, then return a Response with the upstream body and a PDF content type. No browser binary in your Next.js deployment.
Why purchase orders become PDFs
A purchase order is the document a supplier's accounts team matches an invoice against, and it travels by email between two organisations that share no system. That is the difference between a document and a view of a database, and it is why procurement teams keep asking for this.
What a purchase order has to carry
Before any of the code below matters, the template has to produce a document that is actually a purchase order. These are the fields that make it one, and the ones a reader or an auditor will look for first.
- the PO number, which the supplier invoice must quote back
- the ordering entity and the ship-to address, which are often different
- the bill-to address and any cost centre or GL code
- each line with the agreed price, not the supplier list price
- the delivery date required, and the approval reference
Turning your React, rendered to a string on the server template into a document
You already have the markup. RenderToStaticMarkup(<Invoice {...data} />) gives you it as a string, which is the only input the render needs. This is the framework where the incumbent approach fails hardest. A serverless function has a hard bundle size limit, and a Chromium build does not fit inside it. That is why the ecosystem grew a whole genre of stripped Chromium packages, and why an HTTP render is the path of least resistance here rather than an optimisation.
The Next.js implementation
fetch ships with the runtime, so this adds no dependency. The render happens in a Route Handler returning a Response, and you return a Response with the upstream body and a PDF content type.
// app/purchase-orders/[id]/pdf/route.ts
import { renderToStaticMarkup } from "react-dom/server";
import { PurchaseOrderDocument } from "@/documents/purchase-order";
import { documentStyles } from "@/documents/styles";
export async function GET(
_request: Request,
{ params }: { params: Promise<{ id: string }> },
) {
const { id } = await params;
const purchaseOrder = await getPurchaseOrder(id);
// The style tag is the load-bearing part. Your app's CSS lives in a bundle the
// renderer will never fetch, so the document needs its styles inline.
const html = `<!doctype html><html><head><meta charset="utf-8">
<style>${documentStyles}</style></head><body>${renderToStaticMarkup(
<PurchaseOrderDocument purchaseOrder={purchaseOrder} />,
)}</body></html>`;
const upstream = await fetch("https://api.pdfpipe.xyz/v1/pdf", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.PDFPIPE_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
html,
options: { format: "A4", printBackground: true },
}),
});
if (!upstream.ok) {
return new Response("render failed", { status: 502 });
}
return new Response(upstream.body, {
headers: {
"Content-Type": "application/pdf",
"Content-Disposition": `attachment; filename="purchase-order-${id}.pdf"`,
},
});
}The CSS that makes a purchase order page correctly
The layout problem specific to this document is that delivery and billing addresses sit alongside a line item table, and both must stay on the first page where a supplier looks for them. These rules handle it.
/* Backgrounds are dropped unless printBackground is set on the
request, which is the usual reason a document renders in plain
black and white when it looked right in the browser. */
@page {
size: A4;
margin: 18mm 16mm;
}
table { break-inside: avoid; }
h2 { break-after: avoid; }What goes wrong in Next.js
renderToStaticMarkup gives you markup with no stylesheet attached, because your CSS lives in a bundle the PDF renderer will never load. Inline the styles into a style tag in the string you send, or the document renders with browser defaults.
What people try first
Most Next.js projects reach for puppeteer-core paired with a size-reduced Chromium package, which works but ties your deployment to a binary that has to be rebuilt for every runtime version bump. That works until it is running on more than one machine, at which point the browser becomes the thing you operate rather than the thing you use.
Where the purchase order lives afterwards
Rendering is the short part. A PO is retained alongside the invoice it authorised, because the pair is what an auditor matches. In practice it lives in the procurement system for as long as the supplier relationship does, which is longer than most teams plan for.
Getting the document right
- Check the PO number, because an invoice quoting the wrong one will not be paid.
- Generation is triggered by an approval completing in a procurement workflow, so size the timeout for that path rather than for a health check.
- These are produced one at a time by a person who is waiting, so latency is felt directly.
- Backgrounds are painted by default here, so a design that uses colour needs nothing set. Only an explicit print_background of false turns them off.
Frequently asked
Do I need Chromium installed to generate purchase orders from Next.js?
No. The render happens over HTTP, so your Next.js deployment stays the size it is now. That is the main reason to use an API rather than puppeteer-core paired with a size-reduced Chromium package, which works but ties your deployment to a binary that has to be rebuilt for every runtime version bump.
How do I stop a long purchase order using all the memory?
Return a Response with the upstream body and a PDF content type. renderToStaticMarkup gives you markup with no stylesheet attached, because your CSS lives in a bundle the PDF renderer will never load. Inline the styles into a style tag in the string you send, or the document renders with browser defaults.
What has to be on a purchase order?
At minimum: the PO number, which the supplier invoice must quote back; the ordering entity and the ship-to address, which are often different; the bill-to address and any cost centre or GL code. The one to get right before anything else is the PO number, because an invoice quoting the wrong one will not be paid.
Do I need to store the generated purchase orders?
Depends on the document, and this one has a clear answer: a PO is retained alongside the invoice it authorised, because the pair is what an auditor matches. In practice it lives in the procurement system for as long as the supplier relationship does, which is longer than most teams plan for.
Can I keep my existing purchase order template?
Yes, if it produces HTML. Whatever renders your purchase order view today can render the same markup for the PDF, which is why the CSS above is the only new thing you write.
Related
Other Next.js documents, and the same purchase order in other stacks.
Invoice PDFs in Next.js
an invoice is a legal record of a demand for payment
Receipt PDFs in Next.js
a receipt is proof a payment happened
Report PDFs in Next.js
a report is a snapshot of numbers at a moment in time. Its whole value is that it does not change when the underlying dashboard does.
Purchase order PDFs in Node.js
Using fetch, in a route handler that returns the response body directly.
Purchase order PDFs in Python
Using httpx, in an async endpoint that returns a streaming response.
Purchase order PDFs in PHP
Using cURL, in a controller action that echoes the body with a PDF Content-Type.
The same thing in plain Node.js
Without the framework, using fetch directly.
When the output is wrong
Blank pages, missing backgrounds, breaks in the wrong place, by symptom.
All stacks and documents
The full grid of what this covers.
100 free documents a month, no card.