refactor: change definition of tokenData

src/frontend/src/icp-eth/components/tokens/AddTokenByNetwork.svelte

@@ -9,7 +9,6 @@
 	import { nonNullish } from '@dfinity/utils';
 	import { isNetworkIdICP } from '$lib/utils/network.utils';
 	import { isNetworkIdEthereum } from '$lib/utils/network.utils.js';
-	import { onDestroy } from 'svelte';
 
 	export let network: Network | undefined;
 	export let tokenData: Record<string, string>;
@@ -24,13 +23,18 @@
 	let indexCanisterId: string;
 	let erc20ContractAddress: string;
 
-	onDestroy(() => {
-		tokenData = isNetworkIdICP(network?.id)
-			? { ledgerCanisterId, indexCanisterId }
-			: isNetworkIdEthereum(network?.id)
-				? { erc20ContractAddress }
-				: {};
-	});
+	// Since we persist the values of relevant variables when switching networks, this ensures that,
+	// when the user returns to the previous component, only the data related to the selected network
+	// is passed.
+	$: {
+		if (isNetworkIdICP(network?.id)) {
+			tokenData = { ledgerCanisterId, indexCanisterId };
+		} else if (isNetworkIdEthereum(network?.id)) {
+			tokenData = { erc20ContractAddress };
+		} else {
+			tokenData = {};
+		}
+	}
 </script>
 
 <div class="stretch pt-8">