Image Export Demo [yFiles for HTML]

This demo shows how to export the whole diagram or a part of it to a PNG image.

Things to Try

Resize and move the hatched rectangle to control the region which will be exported.
Export shows the exported drawing in an HTML Canvas and as PNG image.
Disable Export Rectangle Contents to export the complete graph instead of the rectangle's region.
Explore the settings for scale and margin.

Details

The demo shows an approach that completely runs in the client's browser, as well as an approach for a server-side export. The client-side export is supported by the latest versions of all major browsers except Internet Explorer 11 whose security settings are more restrictive. In addition, there might be issues in older browsers, especially in Internet Explorer 10 and before.

For more details concerning the shortcomings of the client-side export in this demo's approach and on the related browser deficiencies, see "From SVG to Canvas and Back". Currently, only a server-based image export solution would work in all out-of-date browsers which is also shown in this demo.

Fall-back Strategy

Additionally, this demo shows how to use canvg and the SVG.toDataURL project as a fallback strategy on client-side export. canvg provides a viable workaround for Internet Explorer whose security settings do not allow the creation of a data URL of a HTML Canvas.

This fallback is also used for Microsoft Edge because of a bug that does not allow to draw gradients to a Canvas.

Please note that the canvg result might differ from the original graph visualisation and from the output produced by the primary solution.

This demo loads both of these projects dynamically from their project websites. They are not part of the yFiles for HTML package but available separately under the terms of the MIT license.

Server-side export

The server-side export is a minimal example of how to export the graph using an external service hosted on a server. It shows the export by a Java Servlet that uses the Apache Batik SVG Toolkit and the FreeHEP vectorgraphics, as well as the export via a Node.js express server using headless Chrome/Puppeteer.

The server-side export button will be enabled, when either of the Node.js or Batik Servlet servers are alive on loading time of the demo. To run the servers, see their respective readme in ./java-servlet/ and ./node-server/.

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Client-side Image Export