ktsu.AppDataStorage

ktsu.AppDataStorage is a .NET library designed to simplify the process of managing application data. It facilitates saving and loading configuration or state data to the application's data folder, leveraging JSON serialization.

Features

• Easy-to-use API: Intuitive methods for saving and loading data.
• Automatic Backup: Backs up original files before overwriting to ensure data safety.
• Custom Serialization Options: Uses System.Text.Json with support for custom converters.
• File System Abstraction: Uses System.IO.Abstractions for easy unit testing and mocking.
• Debounced Saves: Prevents frequent file writes to improve performance.
• Support for Multiple Applications: Organizes data by application domain for isolation.
• Static Instance Access: Provides easy access to a singleton-like instance for centralized data management.

Installation

Install the package via NuGet:

dotnet add package ktsu.AppDataStorage

Usage

Defining Your Application Data Class

Create a class that inherits from AppData<T>, where T is your custom data type.

public class MyAppData : AppData<MyAppData>
{
    public string Setting1 { get; set; } = "hello";
    public int Setting2 { get; set; } = 12;
}

Loading Data

Load existing data or create a new instance if no data file exists using LoadOrCreate.

var data = MyAppData.LoadOrCreate();
Console.WriteLine(data.Setting1);
Console.WriteLine(data.Setting2);

// Output:
// hello
// 12

Accessing the Static Instance

The AppData<T> class provides a static instance through the Get method, which ensures a single, easily accessible instance is available throughout your application:

var data = MyAppData.Get();
Console.WriteLine(data.Setting1);

The static instance is initialized automatically and matches the instance returned by LoadOrCreate. Changes to the static instance are persistent once saved:

var data = MyAppData.Get();
data.Setting1 = "new value";
data.Save();

var sameData = MyAppData.Get();
Console.WriteLine(sameData.Setting1);

// Output:
// new value

This functionality is useful for applications where centralized access to app data is required without repeatedly loading or instantiating objects.

Saving Data

Modify properties and save the data using the Save method.

var data = MyAppData.Get();
data.Setting1 = "goodbye";
data.Setting2 = 42;
data.Save();

var reloadedData = MyAppData.Get();
Console.WriteLine(reloadedData.Setting1);
Console.WriteLine(reloadedData.Setting2);

// Output:
// goodbye
// 42

Queued and Debounced Saving

For scenarios with frequent updates, you can queue save operations using QueueSave, which automatically debounces writes to avoid frequent file system operations.

MyAppData.QueueSave();  // Schedules a save
MyAppData.SaveIfRequired();  // Performs the save if the debounce threshold is exceeded

Writing and Reading Arbitrary Text Files

Write and read arbitrary files in the application's data folder using the static AppData class.

Write Text:

AppData.WriteText("example.txt".As<FileName>(), "Hello, AppData!");

Read Text:

string content = AppData.ReadText("example.txt".As<FileName>());
Console.WriteLine(content);

// Output:
// Hello, AppData!

Customizing Serialization

Serialization behavior can be customized using JsonSerializerOptions. By default, the library uses:

• Indented JSON for readability.
• ReferenceHandler.Preserve for circular references.
• Converters such as JsonStringEnumConverter and ToStringJsonConverter.

Directory and File Paths

Data is stored in a directory unique to the current application domain:

var appDataPath = AppData.Path;
Console.WriteLine($"App Data Path: {appDataPath}");

Advanced Features

Backup and Temporary Files

Backup and temporary files are automatically managed during save operations to ensure data integrity:

• Backup file extension: .bk
• Temporary file extension: .tmp

File System Abstraction

The library uses System.IO.Abstractions, allowing you to inject a custom file system implementation for testing.

Contributing

Contributions are welcome! Feel free to open issues or submit pull requests.

License

This project is licensed under the MIT License.