Differentiate between Hot Restart and Hot Reload?
In Flutter, both Hot Restart and Hot Reload are features that enable faster development cycles by allowing developers to see changes in their code without having to rebuild the entire application from scratch. However, they have different behaviors and use cases:
- Hot Reload: Hot Reload is a powerful feature in Flutter that allows developers to quickly see the changes they make to their code reflected in the running app without losing the app’s current state. When you trigger a hot reload, Flutter injects the updated code into the running Dart Virtual Machine (VM) and rebuilds the widget tree. The changes take effect immediately, and the app’s state is preserved.
Characteristics of Hot Reload:
- Fast Iteration: Hot Reload dramatically reduces the development cycle time, enabling developers to see changes instantly without needing to restart the entire app.
- State Preservation: Hot Reload keeps the current app state, which means that if you were in a specific screen or in the middle of a workflow, you can continue from where you left off after the reload.
- Limited Code Changes: Hot Reload works well for most code changes, including UI updates, logic changes, and even some state changes. However, it may not handle certain structural changes or additions of new classes.
Hot Reload is ideal for making quick iterative changes, tweaking UI components, testing out different layouts, and experimenting with small code modifications.
- Hot Restart: Hot Restart is a feature that allows developers to restart the entire Flutter application quickly. When you trigger a hot restart, the entire Dart VM is restarted, and the application goes through the full initialization process again, including creating new instances of widgets and rebuilding the widget tree.
Characteristics of Hot Restart:
- Full Application Restart: Hot Restart completely restarts the application, which means the app state is cleared, and the application starts from its initial state.
- Code and Asset Changes: Hot Restart applies all code changes, including structural changes, new classes, and changes to assets (images, fonts, etc.).
- Useful for Major Changes: Hot Restart is suitable for situations where you need to test significant code changes or when you encounter issues that cannot be resolved with Hot Reload.
Hot Restart is typically used when you want to test major changes to the application, check the behavior from the app’s initial state, or troubleshoot certain issues that might persist after multiple Hot Reloads.
In summary, Hot Reload is designed for rapid development and allows you to see code changes quickly while preserving the app’s state. It is suitable for most iterative changes during development. On the other hand, Hot Restart restarts the entire application from scratch, useful for major code changes, structural changes, or for starting from a clean slate without preserving the current app state. Both features are powerful tools that contribute to Flutter’s fast development cycle and productivity.