mapcomplete/UI/Base/If.svelte

24 lines
667 B
Svelte

<script lang="ts">
import { UIEventSource } from "../../Logic/UIEventSource"
import { onDestroy } from "svelte"
/**
* For some stupid reason, it is very hard to let {#if} work together with UIEventSources, so we wrap then here
*/
export let condition: UIEventSource<boolean>
let _c = condition.data
onDestroy(
condition.addCallback((c) => {
/* Do _not_ abbreviate this as `.addCallback(c => _c = c)`. This is the same as writing `.addCallback(c => {return _c = c})`,
which will _unregister_ the callback if `c = true`! */
_c = c
return false
})
)
</script>
{#if _c}
<slot />
{:else}
<slot name="else" />
{/if}