Add Flutter VC Docs (#1013)

Author: fire-at-will

code_blocks/virtual-currency/vc-balance-sdk-flutter.dart

@@ -0,0 +1,25 @@
+// NOTE: Virtual currencies are not yet supported in Flutter web and
+// are only available for Flutter on iOS and Android.
+
+// Fetch virtual currencies
+try {
+  final virtualCurrencies = await Purchases.getVirtualCurrencies();
+  // TODO: Handle virtual currencies
+} catch (error) {
+  // TODO: Handle error
+}
+
+// Get the details of a specific virtual currency
+final virtualCurrency = virtualCurrencies.all[<virtual_currency_code>];
+final balance = virtualCurrency?.balance;
+final name = virtualCurrency?.name;
+final code = virtualCurrency?.code;
+
+// Keep in mind that serverDescription may be null if no description was provided
+// in the RevenueCat dashboard
+final serverDescription = virtualCurrency?.serverDescription;
+
+// Iterate through all virtual currencies
+virtualCurrencies.all.forEach((virtualCurrencyCode, virtualCurrency) {
+  print('$virtualCurrencyCode: ${virtualCurrency.balance}');
+});

docs/offerings/virtual-currency.mdx

@@ -96,6 +96,7 @@ import fetchVCBalancesSwift from "@site/code_blocks/virtual-currency/vc-balance-
 import fetchVCBalancesKotlin from "@site/code_blocks/virtual-currency/vc-balance-sdk-android.kt?raw";
 import fetchVCBalancesJava from "@site/code_blocks/virtual-currency/vc-balance-sdk-android.java?raw";
 import fetchVCBalancesReactNative from "@site/code_blocks/virtual-currency/vc-balance-sdk-react-native.ts?raw";
+import fetchVCBalancesFlutter from "@site/code_blocks/virtual-currency/vc-balance-sdk-flutter.dart?raw";
 
 Fetching virtual currency balances is supported in the following SDK versions:
 
@@ -104,6 +105,7 @@ Fetching virtual currency balances is supported in the following SDK versions:
 | iOS SDK          | 5.32.0+            |
 | Android SDK      | 9.1.0+             |
 | React Native SDK | 9.1.0+             |
+| Flutter SDK      | 9.1.0+             |
 
 You can use the `virtualCurrencies()` function to retrieve a customer's balance. The function returns a `VirtualCurrencies` object, which includes the customer's balances along with each virtual currency's metadata.
 
@@ -129,6 +131,11 @@ You can use the `virtualCurrencies()` function to retrieve a customer's balance.
       title: "React Native",
       content: fetchVCBalancesReactNative,
     },
+    {
+      type: "flutter",
+      title: "Flutter",
+      content: fetchVCBalancesFlutter,
+    },
   ]}
 />