CoreOne.ModelPatch 1.2.2

CoreOne.ModelPatch

A lightweight and flexible library for applying partial updates to entities in .NET Core and EF Core. Ideal for scenarios where PATCH operations are needed, such as RESTful APIs.

🚀 Features

• Apply partial updates to EF Core entities using JSON Patch-like syntax
• Supports nested properties and complex object graphs
• Easy integration with ASP.NET Core Web APIs
• Reduces boilerplate code for update operations
• Respect unique index contrainsts while inserting objects

📦 Installation

Install via NuGet:

dotnet add package CoreOne.ModelPatch

Or via the NuGet Package Manager:

Install-Package CoreOne.ModelPatch

🛠️ Usage

1. Define Your Entity

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string OtherField { get; set; }
    public Address Location { get; set; }
    public ICollection<Tag> Tags { get; set; }
}

public class Address
{
    public string City { get; set; }
    public string Country { get; set; }
}

[Index(nameof(Value), IsUnique = true)]
public class UserTag
{
    public int Id { get; set; }
    public int UserId { get; set; }
    public string Value { get; set; }

    public User? User { get; set; }
}

2. Create a Patch Model

var model = new User {
    Name = "John",
    Locaion = new Address {
        City = "New York",
        Country = "USA"
    },
    Tags = new List<Tag> {
        new UserTag { Value = "tag1" } // this record is added
        new UserTag { Value = "tag1" } // this one will be ignored
        new UserTag { Value = "tag2" } // this record is added
    }
};

3. Apply the Patch

Only fields present in the delta model are updated, if certain fields are not available then that field does not get the update.

var delta = model.ToDelta();
delta.Remove("OtherField");
var dataService = new DataModelService<YourContext>(IServiceProvider instance, yourContextInstance);
var result = await dataService.Patch(delta);

This will update the Name and Location.City properties of the User entity.

🧪 Sample API Endpoint

private readonly DataModelService _dataService;

public UserController(DataModelService dataService) => _dataService = dataService;

[HttpPatch("{id}")]
public async Task<IActionResult> PatchUser(int id, [FromBody] Delta<User> patchData, CancellationToken cancellationToken)
{
    var result = await _dataService.Patch(delta, cancellationToken);
    return Updated(result);
}

📚 Documentation

The library uses reflection to traverse and update properties. It’s designed to be intuitive and extensible for most EF Core scenarios.

🤝 Contributing

Feel free to fork the repo, submit issues, or open pull requests. Contributions are welcome!

📄 License

This project is licensed under the MIT License.

Would you like help writing unit tests or integrating this into a specific project?