Export

The viewer can turn slides into a range of formats and save the document back to .pptx. Raster formats go through an html2canvas-pro pipeline; PPTX goes through the core serializer.

Supported formats

Format	Pipeline
PNG	renderToCanvas (html2canvas-pro) → canvas.toBlob() → download
PDF	jspdf + per-slide canvases → multi-page PDF (one page per slide, sized to aspect ratio)
GIF	Animated GIF frame encoder (gif-export-helpers)
Video	WebM via the browser MediaRecorder API (video-export-helpers)
Print	Same per-slide capture loop, routed through PrintService
PPTX	PptxHandler.save() → Uint8Array (Save As)

How export is triggered

Export is driven by the viewer's UI, not by inputs or the public API:

• The ribbon's File tab / export actions invoke ViewerExportService, which resolves the live .pptx-ng-canvas-stage element for each slide in turn, captures it to a canvas via ExportService.renderElement, and assembles the result. Progress and cancellation are exposed through the ExportProgressModalComponent (open/title/progress/status signals, with a Cancel button wired to a cooperative AbortController).
• The only public, programmatic way to obtain document bytes is getContent() on the component instance, which returns the serialized .pptx Uint8Array - equivalent to the PPTX "Save As" path.

No export method on the public API

There is no export() method. PNG/PDF/GIF/video exports and printing are user-initiated through the ribbon/dialogs. If you need programmatic raster export of arbitrary DOM, use renderToCanvas (below) directly, or inject ExportService yourself.

renderToCanvas

A standalone utility (exported from the package root) that rasterizes a DOM element to a Canvas, working around browsers' modern-color-space (oklch/oklab/lch/lab/color()) parsing limitations in html2canvas-pro.

import { renderToCanvas } from 'pptx-angular-viewer';

const canvas: HTMLCanvasElement = await renderToCanvas(element, options);

Signature:

function renderToCanvas(
	element: HTMLElement,
	options?: Partial<Html2CanvasOptions>,
): Promise<HTMLCanvasElement>;

It builds on html2canvas-pro and, during the onclone phase, runs the CSS preprocessing pipeline shared with React and Vue (from pptx-viewer-shared, inlined at build time): it converts unsupported color functions to rgb()/hex, and flattens backdrop-filter, mix-blend-mode, and CSS 3D transforms that html2canvas-pro cannot render.

ExportService and ViewerExportService

For advanced integrations you can inject the underlying services directly instead of driving them through the ribbon:

import { ExportService } from 'pptx-angular-viewer';

@Component({ providers: [ExportService] })
export class MyComponent {
	private readonly exportSvc = inject(ExportService);

	async exportPng(el: HTMLElement) {
		await this.exportSvc.exportElementToPng(el, 'slide-1.png');
	}
}

ExportService's methods (savePptx, exportElementToPng, renderElement, exportCanvasesToPdf, exportCanvasesToGif, exportCanvasesToWebm) are pure rasterisation/assembly primitives with no knowledge of the viewer's live slide navigation. ViewerExportService (also exported, see Services) is the higher-level orchestrator the ribbon actually calls: it owns the export-progress modal state, flips the live stage through every slide in turn, and reports per-slide progress, but it requires a bind() call with host accessors (activeSlideIndex, slideCount, mergedSlides, resolveStage) - reach for ExportService directly unless you are reproducing the viewer's own multi-slide export loop.

Pipeline limitations

Raster export inherits the html2canvas-pro constraints (see Limitations):

• backdrop-filter and CSS 3D transforms are not natively supported - the pipeline preprocesses CSS to approximate them, so some fidelity is lost.
• mix-blend-mode is mapped to opacity fallbacks; path gradients become elliptical radials.
• Canvas size is capped by the browser's maximum (commonly 16384×16384 or 32768×32768 px depending on browser/GPU), bounding maximum export resolution.

For the underlying save/serialize details of the PPTX format, see Core.