E # ToDoList Application

ToDoListView	AddToDoView

Video reel

https://www.youtube.com/watch?v=_JOpPdaEeb4 (only open to people who know this link)

Overview

The ToDoList application is a task management tool built using the Composable Architecture in Swift. This README provides an overview of the main components and their responsibilities within the application.

Design Patterns

• The Composable Architecture (TCA): Utilizes TCA to manage state and actions predictably, enhancing modularity and testability.
• Dependency Injection: Services are injected into features for improved decoupling and easier testing.
• Protocol-Oriented Programming: Protocols define service contracts, enhancing flexibility and testability.

Architecture Overview

The application follows a layered architecture consisting of:

• User Interface Layer: Contains views for displaying and adding to-do items.
• Feature Layer: Manages state and logic for adding and listing to-do items.
• Repository / Model Layer: ToDoLocalService and ToDoRemoteService handle local and remote data operations. These services act as repositories by abstracting data access logic, providing a clean API to the Feature Layer. This separation of data retrieval and storage from higher-level application logic enables centralized control over data access, enhancing modularity and testability.

Testing Strategy

Unit tests are implemented for features and services, utilizing mocks and stubs for isolated testing.

Code Structure and Best Practices

The codebase is organized by features, following consistent naming conventions and coding standards.

Future Improvements

Potential enhancements include refactoring for better modularity and integrating additional design patterns.

Commit History

A clear and organized commit history will be maintained to facilitate easy review of changes.

Main Classes Descriptions

AddToDoFeature

The AddToDoFeature is responsible for managing the state and actions related to adding new to-do items within the application.

• Saving Logic: When the user initiates the save operation, the feature asynchronously updates the isSaving state and handles success or failure responses from the service that posts the new to-do item.
• Error Handling: If saving fails, it updates the saveError property with an appropriate error message, which can be displayed to the user.
• State Management: The feature maintains a structured state that reflects the current status of the to-do item being created, ensuring a seamless and responsive user experience.

ToDoListFeature

Manages the state and actions related to displaying and managing the list of to-do items. Key functionalities include:

• Fetching the list of to-do items.
• Handling the addition and deletion of existing to-do items, always prioritizing remote to-do items. Local items are deleted if their IDs are not found in the remote to-do items.
• Ensure that the new todo item is inserted in the correct position using binary search.
• Managing alerts for error handling and confirmations.

DataFetcher

Defines the protocol for making network requests. It abstracts the process of fetching data, allowing for easier testing and mocking. Key responsibilities include:

• Executing data requests and returning responses or errors.

ToDoLocalService

Responsible for managing local storage (SwiftData) operations related to to-do items. It includes methods for:

• Fetching all to-do items from local storage and sorting them by deadline.
• Saving new or updated to-do items.
• Deleting specified to-do items.

ToDoRemoteService

Handles remote service operations for to-do items. It includes methods for:

• Fetching to-do items from a remote server and sorting them by deadline.
• Posting new to-do items to the server.
• Deleting existing to-do items on the server.

ToDoRemoteResponse

Defines the response structure received from the remote service. It encapsulates the details returned from API calls related to to-do items.

ToDoListView

Most of the design is based on the provided screenshots, with a few differences:

• The trash icon is not displayed directly to avoid accidental clicks; instead, it appears when the user taps a button in the top right corner.
• The text displaying the total number of to-do items could not be placed exactly as per the design; I positioned it above the large title.

AddToDoView

Designed according to the provided mockup, with the following differences:

• The Post API cannot be submitted when the title is empty.
• The title is limited to 32 characters.
• The length of each tag is limited to 8 characters, and the total number of tags cannot exceed 3.
• There is an input field for tags along with a preview view for the tags.