ExportService

ExportService renders board pages to image formats for download or sharing.

Supported Formats

Methods

exportBoard

Exports a board to the specified format. Optionally export specific pages.

async exportBoard(
    boardId: string,
    format: ExportFormat,
    pageIds?: string[],
): Promise<Buffer>;

type ExportFormat = 'png' | 'pdf' | 'svg';

• If pageIds is omitted, all pages are included.
• PNG and SVG export only the first page.
• A 40px padding is added around the content.

setCanvasFactory

Provide a server-side canvas factory for PNG rendering. Must be called before any PNG export.

setCanvasFactory(factory: ServerCanvasFactory): void;

interface ServerCanvasFactory {
    createCanvas(width: number, height: number): ServerCanvas;
}

Setup with node-canvas

import { createCanvas } from 'canvas'; // npm package: canvas
import { ExportService } from '@hfu.digital/boardkit-nestjs';

// In your module initialization:
exportService.setCanvasFactory({
    createCanvas(width: number, height: number) {
        return createCanvas(width, height);
    },
});

SVG Export

SVG export works without any external dependencies. It generates a standalone SVG document with:

• White background rectangle
• All elements rendered as SVG primitives (paths, rects, ellipses, text, etc.)
• Proper z-ordering
• Support for strokes, shapes, text, sticky notes, and image placeholders

const svgBuffer = await exportService.exportBoard(boardId, 'svg');
// Write to file or send as response

Element Rendering

The export service renders each element type: