eewing
27 lines
866 B
JavaScript
27 lines
866 B
JavaScript
import { untrack } from "svelte";
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export function watch(box, callback, options = {}) {
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let prev = $state(box.current);
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let ranOnce = false;
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const watchEffect = $effect.root(() => {
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$effect.pre(() => {
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if (prev === box.current || !options.immediate)
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return;
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if (options.once && ranOnce)
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return;
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callback(box.current, untrack(() => prev));
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untrack(() => (prev = box.current));
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ranOnce = true;
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});
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$effect(() => {
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if (prev === box.current || options.immediate)
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return;
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if (options.once && ranOnce)
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return;
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callback(box.current, untrack(() => prev));
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untrack(() => (prev = box.current));
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ranOnce = true;
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});
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});
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return watchEffect;
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}
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