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.agents/skills/svelte-core-bestpractices/references/bind.md

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+## Function bindings
+
+You can also use `bind:property={get, set}`, where `get` and `set` are functions, allowing you to perform validation and transformation:
+
+```svelte
+<input bind:value={() => value, (v) => (value = v.toLowerCase())} />
+```
+
+In the case of readonly bindings like [dimension bindings](#Dimensions), the `get` value should be `null`:
+
+```svelte
+<div bind:clientWidth={null, redraw} bind:clientHeight={null, redraw}>...</div>
+```
+
+> [!NOTE]
+> Function bindings are available in Svelte 5.9.0 and newer.