PDFPipe

Nuxt / reports

Report PDFs in Nuxt

Post your report HTML to a render API from a defineEventHandler in server/api, then return the response body from the event handler. No browser binary in your Nuxt deployment.

Why reports become PDFs

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. That is the difference between a document and a view of a database, and it is why analytics, operations and account teams keep asking for this.

What a report has to carry

Before any of the code below matters, the template has to produce a document that is actually a report. These are the fields that make it one, and the ones a reader or an auditor will look for first.

  • the reporting period as an explicit start and end date
  • the generation timestamp, distinct from the period
  • the data source or filter set, so a reader can tell what was excluded
  • each metric with its unit, since a bare number is not a figure
  • comparison against the prior period where the report claims a trend

Turning your Vue components, rendered with the server renderer template into a document

You already have the markup. Await renderToString(createSSRApp(Invoice, props)) gives you it as a string, which is the only input the render needs. Nitro compiles the same server code to a dozen deployment presets, several of which have no filesystem and no ability to spawn a process. Anything that assumes a local binary ties you to the node preset.

The Nuxt implementation

$fetch ships with the runtime, so this adds no dependency. The render happens in a defineEventHandler in server/api, and you return the response body from the event handler.

typescript
// server/api/reports/[id]/pdf.get.ts
import { createSSRApp } from "vue";
import { renderToString } from "vue/server-renderer";
import ReportDocument from "~/documents/ReportDocument.vue";
import { documentStyles } from "~/documents/styles";

export default defineEventHandler(async (event) => {
  const id = getRouterParam(event, "id");
  const report = await getReport(id);

  const markup = await renderToString(createSSRApp(ReportDocument, { report }));
  const html = `<!doctype html><html><head><meta charset="utf-8">
<style>${documentStyles}</style></head><body>${markup}</body></html>`;

  // arrayBuffer, explicitly. $fetch parses by content type and will try to make
  // sense of PDF bytes as text, which corrupts the file silently.
  const pdf = await $fetch<ArrayBuffer>("https://api.pdfpipe.xyz/v1/pdf", {
    method: "POST",
    headers: { Authorization: `Bearer ${useRuntimeConfig().pdfpipeKey}` },
    body: { html, options: { format: "A4", printBackground: true } },
    responseType: "arrayBuffer",
  });

  setHeader(event, "Content-Type", "application/pdf");
  setHeader(event, "Content-Disposition", `attachment; filename="report-${id}.pdf"`);
  return new Uint8Array(pdf);
});

The CSS that makes a report page correctly

The layout problem specific to this document is that charts and tables must not split mid-element, and a report long enough to matter will page-break somewhere awkward unless break rules are set. These rules handle it.

css
/* Charts and tables must not split. Sections start on a fresh
   page so a heading never ends up alone at the foot of one. */
.chart, figure, table { break-inside: avoid; }
h2 { break-after: avoid; }
section { break-before: page; }
section:first-of-type { break-before: auto; }

@page { size: A4; margin: 20mm 18mm; }

What goes wrong in Nuxt

$fetch parses the response by content type and will try to make sense of PDF bytes as text. Pass responseType: "arrayBuffer" or use the raw handler, or the document arrives corrupted with no error.

What people try first

Most Nuxt projects reach for puppeteer in a server route, with the same preset problem: it works under the node preset and nowhere else. 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 report lives afterwards

Rendering is the short part. Reports pile up faster than any other document here because they are produced on a schedule whether or not anyone reads them. Most teams keep twelve months and expire the rest, which makes storage lifecycle a design decision rather than an afterthought.

Getting the document right

  • Check the period the figures cover, because a report without an unambiguous date range is worse than no report.
  • Generation is triggered by a schedule, usually month end or week end, so size the timeout for that path rather than for a health check.
  • This is a batch shape: render the run through the batch endpoint rather than firing thousands of individual requests.
  • 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 reports from Nuxt?

No. The render happens over HTTP, so your Nuxt deployment stays the size it is now. That is the main reason to use an API rather than puppeteer in a server route, with the same preset problem: it works under the node preset and nowhere else.

How do I stop a long report using all the memory?

Return the response body from the event handler. $fetch parses the response by content type and will try to make sense of PDF bytes as text. Pass responseType: "arrayBuffer" or use the raw handler, or the document arrives corrupted with no error.

What has to be on a report?

At minimum: the reporting period as an explicit start and end date; the generation timestamp, distinct from the period; the data source or filter set, so a reader can tell what was excluded. The one to get right before anything else is the period the figures cover, because a report without an unambiguous date range is worse than no report.

Do I need to store the generated reports?

Depends on the document, and this one has a clear answer: reports pile up faster than any other document here because they are produced on a schedule whether or not anyone reads them. Most teams keep twelve months and expire the rest, which makes storage lifecycle a design decision rather than an afterthought.

Can I keep my existing report template?

Yes, if it produces HTML. Whatever renders your report 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 Nuxt documents, and the same report in other stacks.

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