To make it make sense in my opinion canvas should already be a first class format for web browsers, so it doesn't have to be inside a HTML.
Then we would have a choice of HTML-first page with canvas elements in it, or a canvas-first page with HTML elements in it.
But what do I know.
If you have a canvas-first page, where do you store the title? Right, in <title>, so
<!doctype html>
<title>My canvas site</title>
<canvas style="fill all">
<canvas type="html">
<h1>Canvassing</h1>
</canvas>It's kind of different because SVG and HTML are both XML-like text-based format, doesn't feel that wrong to mix them together. Unlike with canvas..
In most DOM access libraries (like https://github.com/web-dom/web-dom) this Javascript shim exists but is completely invisible to the library user (e.g. it looks and feels as if WASM would have direct DOM access).
Why this topic is always brought up I really have no idea, at this point it feels like trolling attempts because from a technical point of view 'direct DOM access from WASM" simply doesn't make a lot of sense. Accessing web APIs from WASM is an FFI scenario, no matter how you look at it.
When defining standardized DOM APIs in WebIDL, WebIDL assumes that you can use JavaScript strings, JavaScript objects + properties, JavaScript Exceptions, JavaScript Promises, JavaScript garbage collection, and on and on and on. Almost all of the specification of WebIDL itself is about the dozens of types that it assumes the platform already provides. https://webidl.spec.whatwg.org/
WebAssembly doesn’t have any of those things. As a low-level VM, it supports only modules, functions, bytes, numbers (32-bit and 64-bit integers and floats), arrays (called “tables”), and opaque pointers (“reference types”).
No one has ever standardized a DOM API for low-level languages. You’d presumably need to start by defining a new low-level WebIDL design language just to define a low-level DOM API.
Defining WebIDL itself has taken decades.
Today, the browser vendors aren’t convinced that a new low-level DOM API is worth their time. It’s better to make existing JS web apps faster than it is to begin a multi-year (multi-decade?) project to make a new thing possible that could be better in the long run.
Nobody is really calling for exposing the full-suite of WebAPI's. But basic DOM access allowing manipulation of page elements would be immediately leveraged by all the WASM-UI frameworks available today. Framework authors would throw out all the generated JS glue code which adds painful overhead pronto with great joy.
In the end you'll need to marshall datatypes from one language into another, and that is already a mess between 'native' languages (e.g. a C++ std::string is something entirely different than a Rust or Kotlin String).
So in that hypothetical native WASM DOM API, how do you pass something as simple as a string? Let's say the obvious solution would be a ptr/length pair, but then, what encoding UTF-8? UTF-16? UTF-32? No matter what the solution is, you won't find a data representation that directly matches the string representation in all the languages that compile to WASM, so you'll need to do marshalling anyway before calling that hypothetical WASM DOM API.
And suddenly the current 'low-tech' solution of letting a JS shim extract the string data from the WASM heap and build a JS string before calling into a web API suddenly doesn't look so terrible anymore.
A much more impactful change would be to add more WASM-friendly entry points to web APIs.
For instance there's no reason that WebGPU is so 'Javascript object heavy' or uses strings as enum values except that this is common in other Javascript APIs. If WebGPU had additional "WASM-friendly" functions which use plain numbers (as object handles or enum values) a lot of the marshalling overhead when being called from WASM would simply go away.
For strings, the rules are:
The string is encoded as UTF-8.
The ABI lowers it into a (ptr: u32, len: u32) pair in linear memory.
The receiving component or adapter then uses the (ptr, len) to read the UTF-8 bytes and convert it back into its own string representation.
No, the JS shim way is the terrible mess that adds a ridiculous amount of overhead and a truck load of hacks to obtain limited performance. Just have a look at the code for wasm-bindgen for the very definition of messy-engineering and awkward workarounds to get things running.
This feels so much like one of those cases where perfect is the enemy of the good. Node.js spent a decade being wrapped about the axle, convinced that cjs and esm could never work together. Ignoring that it worked great in standard-things/esm. But eventually Bun came around and that somehow made the case that all the hemming & hawing was nonsense all along, that doing nothing was worse than letting Fear Uncertainty and Doubt reign.
It just seems so unlikely that much of JS really matters for webidl. WebIDL specifies mostly structures and routes. It throws some exceptions but that doesn't seem particularly incompatible with wasm. WebIDL has promises, which is already pretty well solved by https://github.com/WebAssembly/js-string-builtins (which alas only Chrome seems to be moving on). GC is also in wasm now. I just don't get the defeatism. Fear Uncertainty and Doubt can be so seductive, anti-belief can be so fierce, and it sucks when things aren't perfect or when there's warts, but the paralysis here & anti-will seems so wildly disproportionately strong.