This document outlines the design for a smart task manager Flutter application. The application will allow users to manage tasks, which will be automatically categorized and prioritized. The design emphasizes scalability, maintainability, and adherence to modern Flutter best practices.
The core problem is to create a task manager that reduces the manual effort of organizing tasks. This is achieved through two main features:
- Automatic Categorization: Tasks are automatically assigned to categories (e.g., "Work", "Personal") based on keywords found in the task description. This eliminates the need for users to manually select a category for each task.
- Automatic Prioritization: Tasks are assigned a priority level (High, Medium, Low) based on their due date. This helps users focus on the most urgent tasks.
The application should be designed to be extensible, with a plan to replace the initial keyword-based categorization with a more intelligent AI-based solution in the future.
- Provider: A popular choice for dependency injection and state management. It's a wrapper around
InheritedWidgetand is relatively easy to use. - Bloc: A more structured approach to state management, using events and states. It's well-suited for complex applications but can be verbose for simpler cases.
- Riverpod: A compile-safe dependency injection and state management solution that addresses some of the pain points of Provider.
- Built-in Solutions (
ChangeNotifier,ValueNotifier): Flutter's built-in tools are often sufficient for simple to moderately complex state management needs. They are lightweight and easy to understand.
For this project, we will start with Flutter's built-in solutions within an MVVM (Model-View-ViewModel) architecture. This provides a good balance of simplicity and structure, and it can be easily scaled or migrated to a more advanced solution like Provider or Riverpod if needed.
- Hard-coded Logic: The simplest approach would be to have a single class with hard-coded
if/elsestatements for categorization. This is not easily extensible. - Strategy Pattern: This pattern defines a family of algorithms, encapsulates each one, and makes them interchangeable. This is a good fit for our needs, as we can define a
CategorizationStrategyinterface and have different implementations for keyword-based and AI-based categorization.
We will use the Strategy Pattern for the categorization service. This will allow us to easily switch between the initial keyword-based implementation and a future AI-based implementation without changing the rest of the application.
We will use a layered architecture based on the principles of Clean Architecture, adapted for a Flutter application. The layers will be:
- Presentation Layer: Contains the UI (widgets and screens) and the ViewModels. This layer will be responsible for displaying the data and handling user input.
- Domain Layer: Contains the business logic of the application. This includes use cases (e.g.,
AddTask,GetTasks), entities (e.g.,Task), and the interfaces for our repositories. - Data Layer: Responsible for data retrieval and storage. This layer will contain the implementation of the repositories and the data sources (e.g., a local database, a remote API).
We will use the MVVM pattern. Each screen will have a corresponding ViewModel, which will be a ChangeNotifier. The ViewModel will expose the state to the UI using ValueNotifiers and will handle the business logic by calling the appropriate use cases from the domain layer.
The categorization service will be implemented using the Strategy Pattern.
TaskCategorizationStrategy(Interface):Future<String> categorize(String taskDescription);
KeywordBasedTaskCategorizationStrategy(Implementation):- Implements the
TaskCategorizationStrategyinterface. - Contains a map of keywords to categories.
- The
categorizemethod will scan the task description for keywords and return the corresponding category.
- Implements the
AIBasedTaskCategorizationStrategy(Future Implementation):- Will also implement the
TaskCategorizationStrategyinterface. - The
categorizemethod will use a machine learning model to classify the task.
- Will also implement the
The prioritization logic will be simpler and can be encapsulated in a utility class or within the Task model itself. A method will take the due date and return the priority level (High, Medium, Low).
lib/
├── main.dart
├── core/
│ ├── usecases/
│ │ ├── add_task.dart
│ │ ├── get_tasks.dart
│ │ └── ...
│ ├── services/
│ │ └── task_categorization_service.dart
│ └── utils/
│ └── priority_util.dart
├── data/
│ ├── models/
│ │ └── task.dart
│ ├── repositories/
│ │ └── task_repository_impl.dart
│ └── datasources/
│ └── local_datasource.dart
├── domain/
│ ├── entities/
│ │ └── task.dart
│ └── repositories/
│ └── task_repository.dart
└── presentation/
├── viewmodels/
│ └── task_list_viewmodel.dart
└── views/
└── task_list_screen.dart
graph TD
A[Presentation Layer (UI, ViewModels)] -->|Calls| B(Domain Layer (Use Cases, Entities))
B -->|Calls| C(Data Layer (Repositories, Data Sources))
graph TD
A[TaskCategorizationService] --> B{TaskCategorizationStrategy};
B --> C[KeywordBasedStrategy];
B --> D[AIBasedStrategy (Future)];
The proposed design uses a layered architecture with MVVM for state management and the Strategy Pattern for the categorization service. This design is modular, testable, and extensible, providing a solid foundation for the smart task manager application.