Data Client

The essential generic data access interfaces for the Flutter News App Toolkit.

This data_client package serves as a foundational shared library for the Flutter News App Full Source Code Toolkit. It defines a generic, abstract interface (DataClient<T>) for interacting with data resources of type T. This interface is designed to handle operations for both user-scoped resources (where data is specific to a user) and global resources (where data is not tied to a specific user, e.g., admin-managed content). The optional userId parameter in methods is used to differentiate between these two use cases.

While its core focus is on providing a standardized contract for common data access patterns, including standard CRUD (Create, Read, Update, Delete) operations, the interface is designed to be extensible to support additional resource-specific methods. It establishes a contract for data clients, expecting implementations to handle underlying communication (like HTTP) and manage serialization/deserialization. This package is designed to be implemented by concrete client classes that interact with specific data sources or APIs.

⭐ Feature Showcase: The Foundation for Robust Data Interaction

This package provides the critical interface for consistent and flexible data access across the entire news application ecosystem.

🧱 Generic & Extensible Data Access

🌐 Core Data Client Interface (DataClient<T>)

• create({String? userId, required T item}): Create a new resource. If userId is null, may represent a global creation.
• read({String? userId, required String id}): Read a single resource by ID. If userId is null, reads a global resource.
• readAll({String? userId, Map<String, dynamic>? filter, PaginationOptions? pagination, List<SortOption>? sort}): Reads multiple resources with powerful filtering, sorting, and pagination.
• update({String? userId, required String id, required T item}): Update an existing resource by ID. If userId is null, updates a global resource.
• delete({String? userId, required String id}): Delete a resource by ID. If userId is null, deletes a global resource.
• count({String? userId, Map<String, dynamic>? filter}): Efficiently counts resources matching a filter without fetching them.
• aggregate({String? userId, required List<Map<String, dynamic>> pipeline}): Executes a complex, server-side aggregation pipeline for analytics and reporting.

⚙️ Advanced Capabilities

• Support for User-Scoped and Global Data: The optional userId parameter allows a single client implementation to handle data specific to a user or data that is globally accessible.
• Advanced Pagination and Sorting: Supports robust, cursor-based pagination (via PaginationOptions) and multi-field sorting (List<SortOption>), ideal for document databases.
• Rich Querying Capability: The readAll method accepts a filter map that can be used to construct complex, MongoDB-style queries.
• Type Safety: Uses generics (<T>) to work with any data model.
• Serialization Agnostic: Defines FromJson<T> and ToJson<T> typedefs, allowing implementations to use their preferred serialization logic.
• Standardized Error Handling: Specifies expected HttpException subtypes (from package:core) that implementations should throw on failure.

💡 Your Advantage: You get a meticulously designed, production-quality data access interface that forms the backbone of a scalable news platform. This package ensures consistent data interaction patterns, saving months of development time and ensuring architectural consistency across your mobile app, web dashboard, and backend API.

🔑 Licensing

This data_client package is an integral part of the Flutter News App Full Source Code Toolkit. For comprehensive details regarding licensing, including trial and commercial options for the entire toolkit, please refer to the main toolkit organization page.