On-the-fly thumbnails in React

Question

I am developing a website with React which has what we called "snippets", basically a modal window displaying some kind of media (audios, videos, slides, text quotations, pdfs). These media have "positions", as a page number, an image number, a playback position, or a scroll position. If she likes the user may store these snippets together with their positions in a "locker" and come back later to whatever is in there. Visually the locker will hold a "thumbnail" of the snippet representing the appearance of the snippet at the time of storing it. My question is how to go about making such a on-the-fly thumbnail. Two approaches come to my mind, however, if you have other ideas I am eager to hear them.

1. Component approach: Since I already have the component, I could reuse or rather clone it, scale it down, disable it for mouse interaction. Would React.cloneElement() be the way to go?

   • Advantage: Easy to do.
   • Disadvantage: Too many duplicates of potentially resource-heavy components may slow down website. Styling may become non-trivial as some embedded media (audio, video) bring their own potentially inaccessible styling with them.

2. Image generation approach: Since I only need an image, I could take a screenshot of the snippet area, scale it down and use it. Can this be done fully (from generation to usage) on the client side? Is there a good library which does the heavy-work for me?

   • Advantage: Resource-heavy only during the making of the thumbnail, resource-light in the locker. Accessible for any styling.
   • Disadvantage: Potentially difficult to do?

Answer 1

After some research I found a solution. Interestingly, it is a mixture of the two approaches I was able to think of. It is possible to access and rasterize the DOM elements which make up the snippets, draw them on a canvas and turn it into an image. The most popular library for this seems to be html2canvas , however, there are a number of others among which rasterizeHTML and html-to-image seem to stand out. Often wrappers for React exist, in the case of html2canvas, for example, use-react-screenshot .