Restrict expression parsing to formatString, and simplify DataModel

.gemini/config.yaml

@@ -7,7 +7,7 @@ have_fun: false
 code_review:
   disable: false
   # Set to -1 for unlimited comments.
-  max_review_comments: 6
+  max_review_comments: 20
   # For now, use the default of MEDIUM for testing. Based on desired verbosity,
   # we can change this to LOW or HIGH in the future.
   comment_severity_threshold: MEDIUM

examples/travel_app/lib/src/catalog/checkbox_filter_chips_input.dart

@@ -123,12 +123,10 @@ final checkboxFilterChipsInput = CatalogItem(
         ? selectedOptionsRef['path'] as String
         : '${context.id}.value';
 
-    final ValueNotifier<List<Object?>?> notifier = context.dataContext
-        .subscribeToObjectArray({'path': path});
-
-    return ValueListenableBuilder<List<Object?>?>(
-      valueListenable: notifier,
-      builder: (buildContext, currentSelectedValues, child) {
+    return BoundList(
+      dataContext: context.dataContext,
+      value: {'path': path},
+      builder: (buildContext, currentSelectedValues) {
         var effectiveSelections = currentSelectedValues;
         if (effectiveSelections == null) {
           if (selectedOptionsRef is List) {
@@ -145,7 +143,10 @@ final checkboxFilterChipsInput = CatalogItem(
           icon: icon,
           selectedOptions: selectedOptionsSet,
           onChanged: (newSelectedOptions) {
-            context.dataContext.update(path, newSelectedOptions.toList());
+            context.dataContext.update(
+              DataPath(path),
+              newSelectedOptions.toList(),
+            );
           },
         );
       },

examples/travel_app/lib/src/catalog/date_input_chip.dart

@@ -129,19 +129,17 @@ final dateInputChip = CatalogItem(
     final path = value is Map && value.containsKey('path')
         ? value['path'] as String
         : '${context.id}.value';
-    final ValueNotifier<String?> notifier = context.dataContext
-        .subscribeToString({'path': path});
-
-    return ValueListenableBuilder<String?>(
-      valueListenable: notifier,
-      builder: (buildContext, currentValue, child) {
+    return BoundString(
+      dataContext: context.dataContext,
+      value: {'path': path},
+      builder: (buildContext, currentValue) {
         final String? effectiveValue =
             currentValue ?? (value is String ? value : null);
         return _DateInputChip(
           initialValue: effectiveValue,
           label: datePickerData.label,
           onChanged: (newValue) {
-            context.dataContext.update(path, newValue);
+            context.dataContext.update(DataPath(path), newValue);
           },
         );
       },

examples/travel_app/lib/src/catalog/information_card.dart

@@ -77,34 +77,30 @@ final informationCard = CatalogItem(
         ? context.buildChild(cardData.imageChildId!)
         : null;
 
-    final ValueNotifier<String?> titleNotifier = context.dataContext
-        .subscribeToString(cardData.title);
-    final ValueNotifier<String?> subtitleNotifier = context.dataContext
-        .subscribeToString(cardData.subtitle);
-    final ValueNotifier<String?> bodyNotifier = context.dataContext
-        .subscribeToString(cardData.body);
-
     return _InformationCard(
       imageChild: imageChild,
-      titleNotifier: titleNotifier,
-      subtitleNotifier: subtitleNotifier,
-      bodyNotifier: bodyNotifier,
+      title: cardData.title,
+      subtitle: cardData.subtitle,
+      body: cardData.body,
+      dataContext: context.dataContext,
     );
   },
 );
 
 class _InformationCard extends StatelessWidget {
   const _InformationCard({
     this.imageChild,
-    required this.titleNotifier,
-    required this.subtitleNotifier,
-    required this.bodyNotifier,
+    required this.title,
+    required this.subtitle,
+    required this.body,
+    required this.dataContext,
   });
 
   final Widget? imageChild;
-  final ValueNotifier<String?> titleNotifier;
-  final ValueNotifier<String?> subtitleNotifier;
-  final ValueNotifier<String?> bodyNotifier;
+  final Object title;
+  final Object? subtitle;
+  final Object body;
+  final DataContext dataContext;
 
   @override
   Widget build(BuildContext context) {
@@ -122,27 +118,31 @@ class _InformationCard extends StatelessWidget {
               child: Column(
                 crossAxisAlignment: CrossAxisAlignment.start,
                 children: [
-                  ValueListenableBuilder<String?>(
-                    valueListenable: titleNotifier,
-                    builder: (context, title, _) => Text(
+                  BoundString(
+                    dataContext: dataContext,
+                    value: title,
+                    builder: (context, title) => Text(
                       title ?? '',
                       style: Theme.of(context).textTheme.headlineSmall,
                     ),
                   ),
-                  ValueListenableBuilder<String?>(
-                    valueListenable: subtitleNotifier,
-                    builder: (context, subtitle, _) {
-                      if (subtitle == null) return const SizedBox.shrink();
-                      return Text(
-                        subtitle,
-                        style: Theme.of(context).textTheme.titleMedium,
-                      );
-                    },
-                  ),
+                  if (subtitle != null)
+                    BoundString(
+                      dataContext: dataContext,
+                      value: subtitle!,
+                      builder: (context, subtitle) {
+                        if (subtitle == null) return const SizedBox.shrink();
+                        return Text(
+                          subtitle,
+                          style: Theme.of(context).textTheme.titleMedium,
+                        );
+                      },
+                    ),
                   const SizedBox(height: 8.0),
-                  ValueListenableBuilder<String?>(
-                    valueListenable: bodyNotifier,
-                    builder: (context, body, _) =>
+                  BoundString(
+                    dataContext: dataContext,
+                    value: body,
+                    builder: (context, body) =>
                         MarkdownWidget(text: body ?? ''),
                   ),
                 ],

examples/travel_app/lib/src/catalog/input_group.dart

@@ -105,9 +105,6 @@ final inputGroup = CatalogItem(
       itemContext.data as Map<String, Object?>,
     );
 
-    final ValueNotifier<String?> notifier = itemContext.dataContext
-        .subscribeToString(inputGroupData.submitLabel);
-
     final List<String> children = inputGroupData.children;
     final JsonMap actionData = inputGroupData.action;
     final event = actionData['event'] as JsonMap?;
@@ -127,12 +124,13 @@ final inputGroup = CatalogItem(
               children: children.map(itemContext.buildChild).toList(),
             ),
             const SizedBox(height: 16.0),
-            ValueListenableBuilder<String?>(
-              valueListenable: notifier,
-              builder: (builderContext, submitLabel, child) {
+            BoundString(
+              dataContext: itemContext.dataContext,
+              value: inputGroupData.submitLabel,
+              builder: (builderContext, submitLabel) {
                 return ElevatedButton(
-                  onPressed: () {
-                    final JsonMap resolvedContext = resolveContext(
+                  onPressed: () async {
+                    final JsonMap resolvedContext = await resolveContext(
                       itemContext.dataContext,
                       contextDefinition,
                     );