chore(flutter): GQL model helper changes for CPK in dev preview (#5124)

Author: Travis Sheppard

src/fragments/lib/graphqlapi/flutter/mutate-data.mdx

@@ -26,11 +26,37 @@ Future<void> deleteTodo(Todo todoToDelete) async {
   final response = await Amplify.API.mutate(request: request).response;
   print('Response: $response');
 }
+```
+
+<BlockSwitcher>
 
+<Block name="Stable (Mobile)">
+
+```dart
 // or delete by ID, ideal if you do not have the instance in memory, yet
 Future<void> deleteTodoById(Todo todoToDelete) async {
   final request = ModelMutations.deleteById(Todo.classType, '8e0dd2fc-2f4a-4dc4-b47f-2052eda10775');
   final response = await Amplify.API.mutate(request: request).response;
   print('Response: $response');
 }
 ```
+
+</Block>
+
+<Block name="Developer Preview (Mobile, Web & Desktop)">
+
+```dart
+// or delete by ID, ideal if you do not have the instance in memory, yet
+Future<void> deleteTodoById(Todo todoToDelete) async {
+  final request = ModelMutations.deleteById(
+    Todo.classType,
+    TodoModelIdentifier(id: '8e0dd2fc-2f4a-4dc4-b47f-2052eda10775'),
+  );
+  final response = await Amplify.API.mutate(request: request).response;
+  print('Response: $response');
+}
+```
+
+</Block>
+
+</BlockSwitcher>

src/fragments/lib/graphqlapi/flutter/query-data.mdx

@@ -2,6 +2,10 @@
 
 Now that you were able to make a mutation, take the `id` from the created `Todo` instance and use it to retrieve data.
 
+<BlockSwitcher>
+
+<Block name="Stable (Mobile)">
+
 ```dart
 Future<Todo?> queryItem(Todo queriedTodo) async {
    try {
@@ -19,6 +23,31 @@ Future<Todo?> queryItem(Todo queriedTodo) async {
 }
 ```
 
+</Block>
+
+<Block name="Developer Preview (Mobile, Web & Desktop)">
+
+```dart
+Future<Todo?> queryItem(Todo queriedTodo) async {
+   try {
+      final request = ModelQueries.get(Todo.classType, queriedTodo.modelIdentifier);
+      final response = await Amplify.API.query(request: request).response;
+      final todo = response.data;
+      if (todo == null) {
+        print('errors: ${response.errors}');
+      }
+      return todo;
+   } on ApiException catch (e) {
+      print('Query failed: $e');
+      return null;
+   }
+}
+```
+
+</Block>
+
+</BlockSwitcher>
+
 ## List items
 
 You can get the list of items in `Amplify.API.query`: