Make document currentscript work

[dralletje]

Instead of eval-ing the code from javascript, I now insert a new script element that gets actually executed (so it becomes the document.currentScript). It won't keep currentScript after anything async, but that also doesn't work with normal scripts either, so I think this just raises compatibility a bunch.

Maybe even deprecate naked currentScript in favor of document.currentScript? but I don't care much either way.

Supersedes #1522

[github-actions]

Try this Pull Request!

Open Julia and type:

julia> import Pkg
julia> Pkg.activate(temp=true)
julia> Pkg.add(url="https://github.com/fonsp/Pluto.jl", rev="make-document-currentscript-work")
julia> using Pluto

[fonsp]

Uh oh, I think I wrote some scripts that use currentScript in async stuff

[dralletje]

Yeah so we might first want to deprecate it if we remove it. You can still do let currentScript = window.currentScript.

But this PR doesn't remove currentScript.

[fonsp]

Can you add some comments to the code? It's too difficult :)

Start by copy pasting your PR description into a docstring?

[fonsp]

Can you add some comments to the code? It's too difficult :)

Start by copy pasting your PR description into a docstring?

[dralletje]

@fonsp 😏

[fonsp]

All the crazy things I could come up with still work, awesome!

# ╔═╡ b474a054-846a-11ec-0f51-1b8e8c589aae
using HypertextLiteral

# ╔═╡ 3b09d217-42b9-473c-b98c-bcbbc1c856a4
@htl """
<span>
	<button>click meeee</button>
	<script>
		const span = currentScript.parentElement
		const btn = span.querySelector("button")

		btn.onclick = () => {
			console.log(currentScript, currentScript.parentElement, document.currentScript)
		}
	</script>
</span>


"""

# ╔═╡ 6868ed5d-0ca4-4a1a-be17-e8bde8f0f8ef
zz

# ╔═╡ adbcbc43-c88a-469b-8e8b-49a20706b415
@bind zz @htl """<script>
	let value = 1

	let handler = setInterval(() => {
		value += 1
		currentScript.value = value
		currentScript.dispatchEvent(
			new CustomEvent("input")
		)
	}, 500)

	invalidation.then(() => {
		clearInterval(handler)
	})
	
</script>
"""

[cjdoris]

@dralletje Thanks so much for this! Can confirm that PythonCall objects (such as Altair plots) now display correctly in Pluto 0.18.0.