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fullenifulleni
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Merge pull request #40 from flutter-news-app-full-source-code/fix-data-route
Fix data route
2 parents 91217ba + 89db404 commit 62f0f50

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‎lib/src/middlewares/data_fetch_middleware.dart‎

Lines changed: 143 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,143 @@
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import 'package:core/core.dart';
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import 'package:dart_frog/dart_frog.dart';
3+
import 'package:data_repository/data_repository.dart';
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import 'package:flutter_news_app_api_server_full_source_code/src/middlewares/ownership_check_middleware.dart';
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import 'package:flutter_news_app_api_server_full_source_code/src/services/dashboard_summary_service.dart';
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import 'package:logging/logging.dart';
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final _log = Logger('DataFetchMiddleware');
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/// Middleware to fetch a data item by its ID and provide it to the context.
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///
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/// This middleware is responsible for:
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/// 1. Reading the `modelName` and item `id` from the context.
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/// 2. Calling the appropriate data repository to fetch the item.
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/// 3. If the item is found, providing it to the downstream context wrapped in a
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/// [FetchedItem] for type safety.
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/// 4. If the item is not found, throwing a [NotFoundException] to halt the
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/// request pipeline early.
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///
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/// This centralizes the item fetching logic for all item-specific routes,
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/// ensuring that subsequent middleware (like ownership checks) and the final
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/// route handler can safely assume the item exists in the context.
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Middleware dataFetchMiddleware() {
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return (handler) {
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return (context) async {
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final modelName = context.read<String>();
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final id = context.request.uri.pathSegments.last;
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_log.info('Fetching item for model "$modelName", id "$id".');
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final item = await _fetchItem(context, modelName, id);
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if (item == null) {
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_log.warning(
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'Item not found for model "$modelName", id "$id".',
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);
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throw NotFoundException(
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'The requested item of type "$modelName" with id "$id" was not found.',
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);
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}
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_log.finer('Item found. Providing to context.');
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final updatedContext = context.provide<FetchedItem<dynamic>>(
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() => FetchedItem(item),
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);
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return handler(updatedContext);
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};
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};
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}
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/// Helper function to fetch an item from the correct repository based on the
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/// model name.
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///
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/// This function contains the switch statement that maps a `modelName` string
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/// to a specific `DataRepository` call.
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///
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/// Throws [OperationFailedException] for unsupported model types.
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Future<dynamic> _fetchItem(
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RequestContext context,
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String modelName,
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String id,
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) async {
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// The `userId` is not needed here because this middleware's purpose is to
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// fetch the item regardless of ownership. Ownership is checked in a
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// subsequent middleware. We pass `null` for `userId` to ensure we are
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// performing a global lookup for the item.
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const String? userId = null;
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try {
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switch (modelName) {
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case 'headline':
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return await context.read<DataRepository<Headline>>().read(
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id: id,
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userId: userId,
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);
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case 'topic':
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return await context
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.read<DataRepository<Topic>>()
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.read(id: id, userId: userId);
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case 'source':
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return await context.read<DataRepository<Source>>().read(
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id: id,
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userId: userId,
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);
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case 'country':
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return await context.read<DataRepository<Country>>().read(
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id: id,
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userId: userId,
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);
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case 'language':
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return await context.read<DataRepository<Language>>().read(
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id: id,
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userId: userId,
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);
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case 'user':
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return await context
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.read<DataRepository<User>>()
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.read(id: id, userId: userId);
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case 'user_app_settings':
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return await context.read<DataRepository<UserAppSettings>>().read(
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id: id,
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userId: userId,
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);
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case 'user_content_preferences':
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return await context
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.read<DataRepository<UserContentPreferences>>()
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.read(
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id: id,
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userId: userId,
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);
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case 'remote_config':
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return await context.read<DataRepository<RemoteConfig>>().read(
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id: id,
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userId: userId,
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);
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case 'dashboard_summary':
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// This is a special case that doesn't use a standard repository.
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return await context.read<DashboardSummaryService>().getSummary();
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default:
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_log.warning('Unsupported model type "$modelName" for fetch operation.');
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throw OperationFailedException(
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'Unsupported model type "$modelName" for fetch operation.',
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);
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}
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} on NotFoundException {
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// The repository will throw this if the item doesn't exist.
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// We return null to let the main middleware handler throw a more
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// detailed exception.
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return null;
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} catch (e, s) {
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_log.severe(
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'Unhandled exception in _fetchItem for model "$modelName", id "$id".',
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e,
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s,
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);
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// Re-throw as a standard exception type that the main error handler
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// can process into a 500 error, while preserving the original cause.
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throw OperationFailedException(
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'An internal error occurred while fetching the item: $e',
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);
142+
}
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}

‎lib/src/middlewares/ownership_check_middleware.dart‎

Lines changed: 25 additions & 40 deletions
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,5 @@
11
import 'package:core/core.dart';
22
import 'package:dart_frog/dart_frog.dart';
3-
import 'package:data_repository/data_repository.dart';
43
import 'package:flutter_news_app_api_server_full_source_code/src/rbac/permission_service.dart';
54
import 'package:flutter_news_app_api_server_full_source_code/src/registry/model_registry.dart';
65

@@ -19,28 +18,27 @@ class FetchedItem<T> {
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/// Middleware to check if the authenticated user is the owner of the requested
2019
/// item.
2120
///
22-
/// This middleware is designed to run on item-specific routes (e.g., `/[id]`).
23-
/// It performs the following steps:
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/// This middleware runs *after* the `dataFetchMiddleware`, which means it can
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/// safely assume that the requested item has already been fetched and is
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/// available in the context.
2424
///
25-
/// 1. Determines if an ownership check is required for the current action
26-
/// (GET, PUT, DELETE) based on the `ModelConfig`.
27-
/// 2. If a check is required and the user is not an admin, it fetches the
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/// item from the database.
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/// 3. It then compares the item's owner ID with the authenticated user's ID.
30-
/// 4. If the check fails, it throws a [ForbiddenException].
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/// 5. If the check passes, it provides the fetched item into the request
32-
/// context via `context.provide<FetchedItem<dynamic>>`. This prevents the
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/// downstream route handler from needing to fetch the item again.
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/// It performs the following steps:
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/// 1. Determines if an ownership check is required for the current action
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/// based on the `ModelConfig`.
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/// 2. If a check is required and the user is not an admin, it reads the
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/// pre-fetched item from the context.
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/// 3. It then compares the item's owner ID with the authenticated user's ID.
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/// 4. If the IDs do not match, it throws a [ForbiddenException].
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/// 5. If the check is not required or passes, it calls the next handler.
3433
Middleware ownershipCheckMiddleware() {
3534
return (handler) {
3635
return (context) async {
37-
final modelName = context.read<String>();
3836
final modelConfig = context.read<ModelConfig<dynamic>>();
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final user = context.read<User>();
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final permissionService = context.read<PermissionService>();
4139
final method = context.request.method;
42-
final id = context.request.uri.pathSegments.last;
4340

41+
// Determine the required permission configuration for the current method.
4442
ModelActionPermission permission;
4543
switch (method) {
4644
case HttpMethod.get:
@@ -50,54 +48,41 @@ Middleware ownershipCheckMiddleware() {
5048
case HttpMethod.delete:
5149
permission = modelConfig.deletePermission;
5250
default:
53-
// For other methods, no ownership check is performed here.
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// For any other methods, no ownership check is performed.
5452
return handler(context);
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}
5654

57-
// If no ownership check is required or if the user is an admin,
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// proceed to the next handler without fetching the item.
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// If no ownership check is required for this action, or if the user is
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// an admin (who bypasses ownership checks), proceed immediately.
5957
if (!permission.requiresOwnershipCheck ||
6058
permissionService.isAdmin(user)) {
6159
return handler(context);
6260
}
6361

62+
// At this point, an ownership check is required for a non-admin user.
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// Ensure the model is configured to support ownership checks.
6465
if (modelConfig.getOwnerId == null) {
6566
throw const OperationFailedException(
6667
'Internal Server Error: Model configuration error for ownership check.',
6768
);
6869
}
6970

70-
final userIdForRepoCall = user.id;
71-
dynamic item;
72-
73-
switch (modelName) {
74-
case 'user':
75-
final repo = context.read<DataRepository<User>>();
76-
item = await repo.read(id: id, userId: userIdForRepoCall);
77-
case 'user_app_settings':
78-
final repo = context.read<DataRepository<UserAppSettings>>();
79-
item = await repo.read(id: id, userId: userIdForRepoCall);
80-
case 'user_content_preferences':
81-
final repo = context.read<DataRepository<UserContentPreferences>>();
82-
item = await repo.read(id: id, userId: userIdForRepoCall);
83-
default:
84-
throw OperationFailedException(
85-
'Ownership check not implemented for model "$modelName".',
86-
);
87-
}
71+
// Read the item that was pre-fetched by the dataFetchMiddleware.
72+
// This is guaranteed to exist because dataFetchMiddleware would have
73+
// thrown a NotFoundException if the item did not exist.
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final item = context.read<FetchedItem<dynamic>>().data;
8875

76+
// Compare the item's owner ID with the authenticated user's ID.
8977
final itemOwnerId = modelConfig.getOwnerId!(item);
9078
if (itemOwnerId != user.id) {
9179
throw const ForbiddenException(
9280
'You do not have permission to access this item.',
9381
);
9482
}
9583

96-
final updatedContext = context.provide<FetchedItem<dynamic>>(
97-
() => FetchedItem(item),
98-
);
99-
100-
return handler(updatedContext);
84+
// If the ownership check passes, proceed to the final route handler.
85+
return handler(context);
10186
};
10287
};
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}

‎routes/_middleware.dart‎

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Original file line numberDiff line numberDiff line change
@@ -34,11 +34,20 @@ Handler middleware(Handler handler) {
3434
if (!_loggerConfigured) {
3535
Logger.root.level = Level.ALL;
3636
Logger.root.onRecord.listen((record) {
37+
// A more detailed logger that includes the error and stack trace.
3738
// ignore: avoid_print
3839
print(
3940
'${record.level.name}: ${record.time}: ${record.loggerName}: '
4041
'${record.message}',
4142
);
43+
if (record.error != null) {
44+
// ignore: avoid_print
45+
print(' ERROR: ${record.error}');
46+
}
47+
if (record.stackTrace != null) {
48+
// ignore: avoid_print
49+
print(' STACK TRACE: ${record.stackTrace}');
50+
}
4251
});
4352
_loggerConfigured = true;
4453
}

‎routes/api/v1/data/[id]/_middleware.dart‎

Lines changed: 19 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -1,18 +1,27 @@
11
import 'package:dart_frog/dart_frog.dart';
2+
import 'package:flutter_news_app_api_server_full_source_code/src/middlewares/data_fetch_middleware.dart';
23
import 'package:flutter_news_app_api_server_full_source_code/src/middlewares/ownership_check_middleware.dart';
34

45
/// Middleware specific to the item-level `/api/v1/data/[id]` route path.
56
///
6-
/// This middleware applies the [ownershipCheckMiddleware] to perform an
7-
/// ownership check on the requested item *after* the parent middleware
8-
/// (`/api/v1/data/_middleware.dart`) has already performed authentication and
9-
/// authorization checks.
7+
/// This middleware chain is responsible for fetching the requested data item
8+
/// and then performing an ownership check on it.
109
///
11-
/// This ensures that only authorized users can proceed, and then this
12-
/// middleware adds the final layer of security by verifying item ownership
13-
/// for non-admin users when required by the model's configuration.
10+
/// The execution order is as follows:
11+
/// 1. `dataFetchMiddleware`: This runs first. It fetches the item by its ID
12+
/// from the database and provides it to the context. If the item is not
13+
/// found, it throws a `NotFoundException`, aborting the request.
14+
/// 2. `ownershipCheckMiddleware`: This runs second. It reads the fetched item
15+
/// from the context and verifies that the authenticated user is the owner,
16+
/// if the model's configuration requires such a check.
17+
///
18+
/// This ensures that the final route handler only executes for valid,
19+
/// authorized requests and can safely assume the requested item exists.
1420
Handler middleware(Handler handler) {
15-
// The `ownershipCheckMiddleware` will run after the middleware from
16-
// `/api/v1/data/_middleware.dart` (authn, authz, model validation).
17-
return handler.use(ownershipCheckMiddleware());
21+
// The middleware is applied in reverse order of execution.
22+
// `ownershipCheckMiddleware` is the inner middleware, running after
23+
// `dataFetchMiddleware`.
24+
return handler
25+
.use(ownershipCheckMiddleware()) // Runs second
26+
.use(dataFetchMiddleware()); // Runs first
1827
}

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