Add pipeToCommand() extension for command chaining (v9.5.0)

New ValueListenable extension that triggers a target command when
the source value changes. Works on any ValueListenable including
commands, isRunning, results, or plain ValueNotifier.

Features:
- Optional transform function to convert source value to target param
- Smart type handling: direct pass if types match, no-param call if not
- Returns ListenableSubscription for manual cancellation

Author: escamoteur

CHANGELOG.md

@@ -1,3 +1,26 @@
+[9.5.0] - 2025-11-29
+
+### New Features
+
+- **Command Piping**: New `pipeToCommand()` extension on `ValueListenable<T>` to chain commands together
+  - When the source ValueListenable changes, automatically triggers the target command
+  - Works on any ValueListenable: commands, `isRunning`, `results`, or plain `ValueNotifier`
+  - Optional `transform` parameter to convert source value to target parameter type
+  - Smart type handling: passes value directly if types match, calls `run()` without param if they don't
+  - Returns `ListenableSubscription` for manual cancellation
+
+**Usage Examples**:
+```dart
+// Trigger refresh after save completes
+saveCommand.pipeToCommand(refreshCommand);
+
+// Transform result before passing to target
+userIdCommand.pipeToCommand(fetchUserCommand, transform: (id) => UserRequest(id));
+
+// Pipe from isRunning to track execution state
+longCommand.isRunning.pipeToCommand(spinnerCommand);
+```
+
 [9.4.2] - 2025-11-25
 
 ### Maintenance

README.md

@@ -166,8 +166,28 @@ Declarative error routing with filters:
 - **[Command Restrictions](https://flutter-it.dev/documentation/command_it/restrictions)** — Disable commands conditionally
 - **[CommandBuilder](https://flutter-it.dev/documentation/command_it/command_builders)** — Widget for simpler UI code
 - **[Undoable Commands](https://flutter-it.dev/documentation/command_it/undoable_commands)** — Built-in undo/redo support
+- **[Command Piping](#piping-commands)** — Chain commands together automatically
 - **[Testing](https://flutter-it.dev/documentation/command_it/testing)** — Patterns for testing commands
 
+### Piping Commands
+
+Chain commands together with the `pipeToCommand()` extension. When the source completes successfully, it automatically triggers the target command:
+
+```dart
+// Trigger refresh after save completes
+saveCommand.pipeToCommand(refreshCommand);
+
+// Transform result before passing to target
+userIdCommand.pipeToCommand(fetchUserCommand, transform: (id) => UserRequest(id));
+
+// Pipe from any ValueListenable - track execution state changes
+longRunningCommand.isRunning.pipeToCommand(spinnerStateCommand);
+```
+
+The `pipeToCommand()` extension works on any `ValueListenable`, including commands, `isRunning`, `results`, or plain `ValueNotifier`. Returns a `ListenableSubscription` for manual cancellation if needed.
+
+> ⚠️ **Warning:** Circular pipes (A→B→A) cause infinite loops. Ensure your pipe graph is acyclic.
+
 ## Ecosystem Integration
 
 **Built on listen_it** — Commands are `ValueListenable` objects, so they work with all listen_it operators (map, debounce, where, etc.).

lib/command_it.dart

@@ -2394,3 +2394,50 @@ abstract class Command<TParam, TResult> extends CustomValueNotifier<TResult> {
     return command;
   }
 }
+
+/// Extension to pipe [ValueListenable] changes to a [Command].
+///
+/// This allows chaining commands - when the source ValueListenable changes,
+/// it automatically triggers the target command.
+///
+/// **Warning**: Circular pipes (A→B→A) will cause infinite loops.
+/// Ensure your pipe graph is acyclic.
+///
+/// Example:
+/// ```dart
+/// // Trigger refresh after save completes
+/// saveCommand.pipeToCommand(refreshCommand);
+///
+/// // With transform function
+/// userIdCommand.pipeToCommand(fetchUserCommand, transform: (id) => UserRequest(id));
+///
+/// // Pipe from isRunning to track execution state
+/// longCommand.isRunning.pipeToCommand(spinnerCommand);
+/// ```
+extension ValueListenablePipe<T> on ValueListenable<T> {
+  /// Triggers [target] command whenever this ValueListenable's value changes.
+  ///
+  /// - If [transform] is provided, transforms the value before passing to target
+  /// - If [transform] is null and value is assignable to TTargetParam, passes directly
+  /// - If [transform] is null and types don't match, calls target.run() without param
+  ///   (useful for triggering no-param commands)
+  ///
+  /// Returns the [ListenableSubscription] for manual cancellation if needed.
+  /// Normally, the subscription is automatically cleaned up when the source
+  /// ValueListenable is disposed.
+  ListenableSubscription pipeToCommand<TTargetParam, TTargetResult>(
+    Command<TTargetParam, TTargetResult> target, {
+    TTargetParam Function(T value)? transform,
+  }) {
+    return listen((value, _) {
+      if (transform != null) {
+        target.run(transform(value));
+      } else if (value is TTargetParam) {
+        target.run(value);
+      } else {
+        // Types don't match, call without param (for void/no-param targets)
+        target.run();
+      }
+    });
+  }
+}

pubspec.yaml

@@ -1,6 +1,6 @@
 name: command_it
 description: command_it is a way to manage your state based on `ValueListenable` and the `Command` design pattern. It is a rebranding of flutter_command.
-version: 9.4.2
+version: 9.5.0
 homepage: https://github.com/flutter-it/command_it
 
 screenshots: