print

Generic action-based PDF representation of object.

This documentation was written by an artificial intelligence and may contain errors or approximations. It has not yet been fully reviewed by a human. If anything seems unclear or incomplete, please feel free to contact the author of this package.

Installation

npm i @itrocks/print

Usage

@itrocks/print provides a simple action that can be used as a starting point for generating PDF documents from your backend.

The main export is the Print<T> action which:

• is decorated with @Need('object') so it expects a domain object to be loaded for the current request,
• is decorated with @Route('/print') when used with @itrocks/route,
• extends the generic Action<T> base class from @itrocks/action,
• exposes a single method pdf() that generates a PdfResponse.

In the reference implementation the PDF content itself is intentionally minimal (a single page with a sample text). You are expected to adapt or extend the action for your own project to render whatever representation of your objects you need.

Minimal example

import { Print } from '@itrocks/print'
import type { Request } from '@itrocks/action-request'

class Invoice {
	number   = ''
	customer = ''
}

// Simple instance of the generic Print action
const printInvoice = new Print<Invoice>()

// Route handler that returns a PDF response
async function invoicePdf (request: Request<Invoice>) {
	// In a typical it.rocks stack, `request` is built for you by
	// @itrocks/action-request from the HTTP layer
	return printInvoice.pdf(request)
}

The Request<Invoice> type is usually constructed by @itrocks/action-request from an incoming HTTP request (Fastify, Express, …).

Example with Fastify and @itrocks/route

When you use @itrocks/print together with @itrocks/route, the @Route('/print') decorator and the config.yaml of this package can be used to wire a conventional /print endpoint.

import fastify from 'fastify'
import { toActionRequest } from '@itrocks/action-request-fastify'
import { Print } from '@itrocks/print'
import type { Request } from '@itrocks/action-request'

class Invoice {
	id       = 0
	number   = ''
	customer = ''
}

const app          = fastify()
const printInvoice = new Print<Invoice>()

app.get('/invoices/:id/print', async (req, reply) => {
	const request: Request<Invoice> = toActionRequest<Invoice>(req)
	const response = await printInvoice.pdf(request)

	reply
		.status(response.status)
		.headers(response.headers)
		.type('application/pdf')
		.send(response.body)
})

app.listen({ port: 3000 })

This keeps your HTTP layer thin while delegating the PDF generation logic to the action itself.

API

class Print<T extends object = object> extends Action<T>

Print<T> is a generic action designed to generate a PDF representation for an object of type T.

From the implementation you can see that it is decorated with:

• @Need('object') – the action expects the current Request<T> to be able to resolve an object instance (typically via getObject() from the base Action<T> class).
• @Route('/print') – declares a conventional /print route when used with @itrocks/route.

Type parameter:

• T – the domain object type for which you want to generate a PDF (for example Invoice, Order, User, …).

Methods

pdf(): Promise<PdfResponse>

Builds a PDF document and returns it wrapped in a PdfResponse from @itrocks/core-responses.

In the default implementation the PDF contains a single page with a sample text. In your own projects you will usually:

• subclass Print<T> and override pdf() to build a document that uses the properties of your object, or
• copy the pattern and adapt it inside a custom action that extends Action<T> directly.

The returned PdfResponse exposes the usual properties used by @itrocks/core-responses (status, headers, body…), so it can be returned as‑is by your HTTP framework adapters.

Typical use cases

• Provide a basic /print endpoint for a given entity (invoice, order, user profile, …) without wiring PDF generation manually in every route.
• Use Print<T> as a minimal tutorial or starting point for using pdfkit and PdfResponse within the it.rocks action ecosystem.
• Prototype PDF exports quickly, then replace the sample implementation of pdf() with richer layouts (multi‑page documents, tables, branding, etc.).
• Offer a conventional PDF export option alongside existing HTML/JSON actions in your domain‑specific action packs.