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Comment by bhl | Hacker News Reader

With a canvas-based engine, the editor is no longer relying on the contenteditable spec right?

For the majority of use cases, do you think contenteditable + view layer which precisely updates the HTML is still viable? More specifically, what do you think about open-source libraries like ProseMirror (https://prosemirror.net/) or Slate.js (https://github.com/ianstormtaylor/slate) which do that (ProseMirror uses its own view library on vanilla javascript, Slate uses React)?

I understand if you have really long documents or spreadsheets (I imagine latter is more frequent), you could maybe solve performance rendering problems with virtualization, which canvas gives more flexibility to?

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> With a canvas-based engine, the editor is no longer relying on the contenteditable spec right?

Correct. In fact, contenteditable went out the window a decade ago when the "#2" engine (low-level DOM manipulation) was launched.

My experience with contenteditable is ~12 years stale at this point, so the only thing I'll try to say is that I expect it would work well up to a certain level of ambition, and no further. As I say above regarding frameworks: they're great so long as your requirements fit within the expectations of the framework, but you quickly hit a wall if you need to stray outside of that. For Docs, the desire for a paginated view/edit mode was an example; there was simply no sane way of squeezing pagination into a contenteditable-based engine.

My experience with modern contenteditable suggests that it does work pretty well, overall, though I've not been using it for something as layout-heavy as Docs -- I've worked on the VisualEditor for mediawiki, which has different requirements.

A canvas-based document editor with any sort of international ambitions has a fairly high bar to clear for reimplementing basic features. The browsers really do handle a lot of useful things for you in contenteditable, like the upthread-mentioned RTL issues, and complex IME input methods.

If you have a lot of HTML-rendering inherently required, strong internationalization requirements, and no need for something like page-based layout... contenteditable has advantages, particularly when comparing the up-front work required.

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