Show HN: I created snapDOM to capture DOM nodes as images with exceptional speed(github.com)
120 pointsby tinchox69 months ago18 comments
  • streptomycin9 months ago
    I've been using html2canvas for a long time in https://play.basketball-gm.com/ so I gave your library a try. It was much slower (I know your README has benchmarks saying the opposite so idk) and the result looked a lot worse.

    html2canvas: https://i.imgur.com/zfSwNR1.png

    snapdom: https://i.imgur.com/FxowTzp.png

    Also I recommend putting the npm package name clearly in your README. I guess I don't really know what other people are doing these days, but I think most people are like me and consume packages like this from npm rather than a <script> tag.

    • tinchox69 months ago
      Thank you for testing it out and sharing the screenshots!

      I’ve run some performance tests using Vitest Bench, and SnapDOM was faster. I also created a few manual demos, and SnapDOM won in both speed and accuracy.

      That said, I still need to run more real-world tests. So, thanks again for your help!

    • tinchox69 months ago
      If interested I solved almost all issues you pointed out (speedy and accuracy).

      https://github.com/zumerlab/snapdom/issues/3

    • tinchox69 months ago
      I added to README the npm / yarn reference. Thanks!
  • jdiff9 months ago
    Capturing HTML as scalable SVGs is huge, how do you manage condensing all of CSS and its quirks into an SVG? Do you only support a subset of styling properties and rely on the browser to calculate layouts for you?
    • tinchox69 months ago
      I was upset about the size of generated svg file because at first all styles were inlined in each element. So I created a function to make mini css classes (.c1, c2, c3,...) So the final size is quite small.
  • krebby9 months ago
    How does this compare to something like the the Media Capture API? Looks like this uses `canvas.toDataURL()` which can be slow to serialize compared to `toBlob` or `canvas.captureStream(0).getVideoTracks()`

    I've been using CropTarget.fromElement with a CaptureController: https://gist.github.com/akre54/e93ab2ce27999aecb109e38085f2e...

  • simonw9 months ago
    Tiny feature request: snapdom.toJpg(el) appears to return a JPEG image where the background color for any transparent areas is set to black - it would be useful to be able to set that to another color (I needed it to be white).
  • Sephr9 months ago
    Awesome! I was making exactly this library 13 years ago but only made it as far as creating CSS and other asset inlining+normalization tools before I ran into a few major roadblocks.

    The most significant roadblock was that drawing SVG <foreignObject> with inline subresources (data: and blob: URIs) tainted canvases in Chrome and Safari, and this was partially resolved in 2019[1].

    Notably, some issues still remain but apparently it's now workable. As is apparent from snapDOM, completely accurate CSS normalization is still an unsolved problem.

    While I'm excited to see the HTML-in-foreignObject use case mature, it is also important to point out that the Media Capture API now has the ability to capture individual elements natively in Chrome[2].

    1. https://issues.chromium.org/issues/41054640#comment49

    2. https://developer.mozilla.org/en-US/docs/Web/API/CropTarget/...

  • ashishact9 months ago
    Image in the readme would really be helpful. In fact anytime there is a visual output it makes sense to put an image. Thanks for creating this though - Will give it a try for an upcoming project.
    • tinchox69 months ago
      Thank you for the suggestion!
  • darrenf9 months ago
    I’ve been writing a browser extension recently, and part of the functionality I want is to export part of a view as an image, shareable for the socials. I wanted to use html2canvas, but the docs explicitly advise against using it in a browser extension. Would snapDOM be suitable for inclusion in an extension?
    • genewitch9 months ago
      Firefox has screenshot that auto-picks elements, or you can click and drag a crop, or you can save the whole page. That and ad nauseam are the reason I use firefox; that singlefile also works is great (single html file dump of a web page, somehow).
    • tinchox69 months ago
      Sincerely, I don't know if snapdom would work on a browser extension. I've never tested it on this scenery
    • 9 months ago
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  • maxloh9 months ago
    Maybe add a function to convert to PDF? I've always dreamed of converting an element or the document body to a long-scrolling PDF. I tried to implement it with Playwright Python, but I had no luck. The resulting PDF height is messed up.
    • tinchox69 months ago
      Its a bit out of scope right now, but I thing it would be possible using some external libraries such as jsPDF or svg2pdf.js
  • G_o_D9 months ago
    It doesnt load, snapdom dont appear in my devtools had to copy paste script

    Plus it just struck at pending promise dont work

    Plus css is messed up, i cant call it a snapshot, if it dont look same

    domtoimage lib works for me and is fast whole html body node captured within second

  • rs1869 months ago
    How does this compare with https://www.npmjs.com/package/dom-to-image-more?
    • tinchox69 months ago
      It is pretty the same idea. There are many good solutions like dom-to-imge-more: the battle tested html2canvas, dom-to-image, modern-screenshot, etc. SnapDom is focused on avoiding long-taks whenever is possible because was designed to a zoomble UI engine that needs the capture doesnt affect the transition. But this is the first public version and there many things to adjust.
  • braebo9 months ago
    I found puppeteer or playwright to be good at this with their screenshot method. I made a cli tool for this recently that worked quite well.
    • tinchox69 months ago
      Yes they are so good. But in my case I need to work only on the client side
  • matt-attack9 months ago
    Can you explain what the use case is for this tool?
  • badmonster9 months ago
    Does snapDOM support capturing elements with CSS animations in their current frame, or does it only capture static states?
    • tinchox69 months ago
      Yes it capture elements with css animations in theirr current frame. It isnt't work for animted gifs. And I have to test js animations engines
  • andrewstuart9 months ago
    Screenshots on the GitHub would be great.
    • Eduard9 months ago
      Not only screenshots, but also actual results. As I understand the short description, this tool allows to transform a website's current visual state into an SVG.
  • nikeee9 months ago
    Does it work with some DOM polyfill in Node.js?
  • imvetri9 months ago
    How does it work
  • andrewstuart9 months ago
    Why not do it at the back end where you can literally snapshot node to png.