svelte/test/runtime/samples/onrender-chain/Item.html

<span>{{foo}}</span>

<script>
	export default {
		data () {
			return {
				foo: 'XX'
			};
		},
		oncreate () {
			this.observe( 'item', item => {
				this.set({ foo: item });
			});
		}
	};
</script>