fix: Update 31-legacy-svelte-self.md

[jaminwebdev]

Addresses #15160

https://svelte.dev/docs/svelte/legacy-svelte-self shows old prop declaration syntax

<script>
	export let count;
</script>

{#if count > 0}
	<p>counting down... {count}</p>
	<svelte:self count={count - 1} />
{:else}
	<p>lift-off!</p>
{/if}

Should probably update to $props()

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[Conduitry]

I'm undecided how I feel about this. This is supposed to be demonstrating legacy syntax and how to convert it - but it's <svelte:self> that we're demonstrating how to convert here, not export props. I don't know whether we want to show other aspects of the component in old syntax or new syntax.

[jaminwebdev]

I'm undecided how I feel about this. This is supposed to be demonstrating legacy syntax and how to convert it - but it's <svelte:self> that we're demonstrating how to convert here, not export props. I don't know whether we want to show other aspects of the component in old syntax or new syntax.

Understood. Was basing it from https://svelte.dev/docs/svelte/v5-migration-guide#svelte:component-is-no-longer-necessary, but I suppose this isn't documentation related to migrating

[Ocean-OS]

I'm undecided how I feel about this. This is supposed to be demonstrating legacy syntax and how to convert it - but it's <svelte:self> that we're demonstrating how to convert here, not export props. I don't know whether we want to show other aspects of the component in old syntax or new syntax.

I feel like mixing the old and new syntax will just lead to confusion.

[gterras]

I think removing the old docs was already a harsh move for v4 users. I understand switching to V5 is quite easy and all the information needed for v4 is still there, and the team wants to push v5 which is good, but traditional usage in this case is just to have a version selector on the docs page.

There are still people using v4 out there, and navigating the current docs is already hard enough for them. Mixing v5 syntax in legacy pages will make it even harder.

[dummdidumm]

The old site is on https://v4.svelte.dev and it's linked to right on the https://svelte.dev/docs page

[gterras]

The old site is on https://v4.svelte.dev and it's linked to right on the https://svelte.dev/docs page

Sorry I wasn't aware of this, it doesn't matter that much then, I think a point in favor of having full v4 syntax in legacy v5 docs is that maintenance is easier (it won't ever need to be updated).