@mlightcad/cad-pdf-plugin

PDF export and import plugin for @mlightcad/cad-simple-viewer. Registers two system commands:

| Command | Description | |---------|-------------| | cpdf | Export the current drawing to a vector PDF (SVG pipeline → jsPDF) | | ipdf | Import vector geometry from a PDF file into model space |

The plugin is designed for lazy loading so PDF libraries (jspdf, pdfjs-dist, svg2pdf.js) are only downloaded when a user runs cpdf or ipdf.

Key features

• Vector PDF export — renders model-space entities via @mlightcad/cad-svg-plugin, then converts SVG to PDF with svg2pdf.js
• PDF import — parses vector paths from the first page of a PDF (lines, polylines, Bézier curves) and appends CAD entities
• Plugin API — implements AcApPlugin; register once with registerLazyPdfPlugin
• Framework-agnostic — no Vue/React dependency; works anywhere cad-simple-viewer runs

Installation

pnpm add @mlightcad/cad-pdf-plugin

Peer dependencies:

• @mlightcad/cad-simple-viewer
• @mlightcad/data-model
• @mlightcad/cad-svg-plugin

Runtime dependencies (bundled with this package):

• jspdf
• pdfjs-dist
• svg2pdf.js

Build

pnpm --filter @mlightcad/cad-pdf-plugin build

Usage

Lazy registration (recommended)

Register the plugin with the document manager's plugin manager. The module chunk loads on first use of cpdf or ipdf:

import { AcApDocManager } from '@mlightcad/cad-simple-viewer'
import { registerLazyPdfPlugin } from '@mlightcad/cad-pdf-plugin'

registerLazyPdfPlugin(AcApDocManager.instance.pluginManager)

Equivalent manual registration:

import {
  createPdfPlugin,
  PDF_PLUGIN_NAME,
  PDF_PLUGIN_TRIGGERS
} from '@mlightcad/cad-pdf-plugin'

AcApDocManager.instance.pluginManager.registerLazyPlugin({
  name: PDF_PLUGIN_NAME,
  triggers: [...PDF_PLUGIN_TRIGGERS],
  loader: createPdfPlugin
})

After registration, users (or your UI) invoke commands through the editor:

// Export current drawing to PDF
await AcApDocManager.instance.editor.executeCommand('cpdf')

// Open file picker and import PDF vectors
await AcApDocManager.instance.editor.executeCommand('ipdf')

cad-viewer registers this plugin automatically via registerLazyPlugins() in its app bootstrap.

Eager registration

If you prefer loading PDF support up front:

import { AcApPdfPlugin } from '@mlightcad/cad-pdf-plugin'

await AcApDocManager.instance.pluginManager.loadPlugin(new AcApPdfPlugin())

Programmatic convertors

You can bypass the command layer and call the convertors directly:

import { AcApContext } from '@mlightcad/cad-simple-viewer'
import { AcApPdfConvertor, AcApPdfImportConvertor } from '@mlightcad/cad-pdf-plugin'

// Export
const context: AcApContext = /* active context */
await new AcApPdfConvertor().convert(context)

// Import from bytes
const buffer: ArrayBuffer = /* PDF file */
await new AcApPdfImportConvertor().convert(context, buffer, 1) // page 1

How it works

Export (cpdf)

1. Iterate model-space entities and render with AcSvgRenderer (respects linetype scale, lineweight display, font mapping, background/foreground colors).
2. Parse the SVG and pass it to svg2pdf.js inside a jsPDF document sized to the SVG viewBox.
3. Trigger a browser download as drawing.pdf.

Import (ipdf)

1. Show a native file picker (.pdf).
2. Use pdfjs-dist to read operator lists from the selected page.
3. Convert path operators (move, line, cubic Bézier, close) into AcDbLine / AcDbPolyline entities in model space.

Import is vector-only; raster/scanned PDF pages produce no entities. Only the requested page is processed (default: page 1).

Main exports

| Export | Role | |--------|------| | registerLazyPdfPlugin | One-line lazy registration helper | | createPdfPlugin | Async factory used by lazy loader | | PDF_PLUGIN_NAME, PDF_PLUGIN_TRIGGERS | Plugin id and command triggers | | AcApPdfPlugin | AcApPlugin implementation | | AcApConvertToPdfCmd | cpdf command class | | AcApImportPdfCmd | ipdf command class | | AcApPdfConvertor | SVG → PDF export utility | | AcApPdfImportConvertor | PDF → CAD entities import utility |

Project layout

| Path | Role | |------|------| | src/registerLazyPdfPlugin.ts | Lazy plugin registration API | | src/AcApPdfPlugin.ts | Plugin lifecycle (onLoad / onUnload) | | src/AcApConvertToPdfCmd.ts | cpdf command | | src/AcApImportPdfCmd.ts | ipdf command | | src/AcApPdfConvertor.ts | Export pipeline (SVG renderer + jsPDF) | | src/AcApPdfImportConvertor.ts | Import pipeline (pdf.js operator parsing) |

Role in MLightCAD

This package extends cad-simple-viewer with optional PDF I/O. It depends on cad-svg-plugin for export quality parity with the existing SVG export command (csvg) and keeps heavy PDF dependencies out of the core viewer bundle through lazy loading.

License

MIT