update: updating comments

packages/http/lib/foundation.dart

@@ -9,19 +9,28 @@
 
 /// This library exports various foundation classes and utilities for web-related operations.
 ///
-/// It includes:
-/// - [CountableInterface] for objects that can be counted
-/// - [Cookie] for handling HTTP cookies
-/// - [HeaderUtils] for working with HTTP headers
-/// - [HeaderBag] for managing collections of HTTP headers
-/// - [ParameterBag] for handling request parameters
-/// - [ResponseHeaderBag] for managing response headers
+/// Exports:
+/// - [CountableInterface] from 'src/foundation/countable_interface.dart'
+/// - [StringableInterface] from 'src/foundation/stringable_interface.dart'
+/// - [Filter] from 'src/foundation/filter.dart'
+/// - [Cookie] from 'src/foundation/cookie.dart'
+/// - [HeaderUtils] from 'src/foundation/header_utils.dart'
+/// - [HeaderBag] from 'src/foundation/header_bag.dart'
+/// - [ParameterBag] from 'src/foundation/parameter_bag.dart'
+/// - [InputBag] from 'src/foundation/input_bag.dart'
+/// - [ResponseHeaderBag] from 'src/foundation/response_header_bag.dart'
+///
+/// These exports provide a comprehensive set of tools for handling various aspects of web development,
+/// including countable objects, string manipulation, filtering, cookies, HTTP headers, request parameters,
+/// and response handling.
 library;
 
 export 'src/foundation/countable_interface.dart';
 export 'src/foundation/stringable_interface.dart';
+export 'src/foundation/filter.dart';
 export 'src/foundation/cookie.dart';
 export 'src/foundation/header_utils.dart';
 export 'src/foundation/header_bag.dart';
 export 'src/foundation/parameter_bag.dart';
+export 'src/foundation/input_bag.dart';
 export 'src/foundation/response_header_bag.dart';

packages/http/lib/src/foundation/parameter_bag.dart

@@ -346,39 +346,45 @@ abstract class ParameterBag implements Iterable<MapEntry<String, dynamic>>, Coun
     }
   }
 
-  /// Filters and transforms a parameter value using a provided function.
+  /// Filters a parameter value based on the given key.
   ///
   /// This method retrieves the value associated with the given [key] and applies
-  /// a [filterFunction] to transform or validate it. If the key doesn't exist,
-  /// it returns the [defaultValue].
+  /// basic filtering logic. If the key doesn't exist, it returns the [defaultValue].
+  ///
+  /// The current implementation provides a simple string sanitization for string values,
+  /// trimming whitespace from the beginning and end. For all other types, the value
+  /// is returned as-is.
+  ///
+  /// This method is designed to be overridden or extended in subclasses to provide
+  /// more sophisticated filtering logic.
   ///
   /// Parameters:
-  ///   [key] - The key of the parameter to retrieve and filter.
-  ///   [defaultValue] - Optional. The value to return if the key is not found.
-  ///   [filterFunction] - A function that takes the parameter value as input
-  ///                      and returns a transformed or validated value.
+  ///   [key] - The key of the parameter to filter.
+  ///   [defaultValue] - Optional. The value to return if the key doesn't exist.
+  ///   [filter] - Optional. An integer representing the filter type (not used in the base implementation).
+  ///   [options] - Optional. Additional options for filtering (not used in the base implementation).
   ///
   /// Returns:
-  ///   The filtered and transformed parameter value, or the defaultValue if
-  ///   the key is not found.
-  ///
-  /// Throws:
-  ///   [UnexpectedValueException] if the filterFunction throws an exception,
-  ///   indicating that the parameter value is invalid.
+  ///   The filtered value if the key exists, otherwise the [defaultValue].
   ///
   /// Example:
-  ///   var age = parameterBag.filter('age',
-  ///     defaultValue: 0,
-  ///     filterFunction: (value) => int.parse(value.toString()));
-  dynamic filter(String key, {dynamic defaultValue, required String Function(dynamic) filterFunction}) {
-    final value = get(key, defaultValue);
-    if (value == null) return defaultValue;
-
-    try {
-      return filterFunction(value);
-    } catch (e) {
-      throw UnexpectedValueException('Parameter value "$key" is invalid: ${e.toString()}');
+  ///   parameterBag.set('name', '  John Doe  ');
+  ///   print(parameterBag.filter('name')); // Outputs: 'John Doe'
+  dynamic filter(String key, {dynamic defaultValue, int? filter, dynamic options}) {
+    if (!has(key)) {
+      return defaultValue;
     }
+
+    var value = get(key);
+
+    // Basic filtering logic, can be overridden or extended in subclasses
+    if (value is String) {
+      // Simple string sanitization as an example
+      return value.trim();
+    }
+
+    // For other types, return as is
+    return value;
   }
 
   /// Returns an iterator for the entries in the parameters map.