Microsoft.AspNetCore.JsonPatch

About

Microsoft.AspNetCore.JsonPatch provides ASP.NET Core support for JSON PATCH requests.

How to Use

To use Microsoft.AspNetCore.JsonPatch, follow these steps:

Installation

dotnet add package Microsoft.AspNetCore.JsonPatch
dotnet add package Microsoft.AspNetCore.Mvc.NewtonsoftJson

Configuration

To enable JSON Patch support, call AddNewtonsoftJson in your ASP.NET Core app's Program.cs:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddControllers()
    .AddNewtonsoftJson();

Configure when using System.Text.Json

To add support for JSON Patch using Newtonsoft.Json while continuing to use System.Text.Json for other input and output formatters:

1. Update your Program.cs with logic to construct a NewtonsoftJsonPatchInputFormatter:

   static NewtonsoftJsonPatchInputFormatter GetJsonPatchInputFormatter()
   {
       var builder = new ServiceCollection()
           .AddLogging()
           .AddMvc()
           .AddNewtonsoftJson()
           .Services.BuildServiceProvider();
   
       return builder
           .GetRequiredService<IOptions<MvcOptions>>()
           .Value
           .InputFormatters
           .OfType<NewtonsoftJsonPatchInputFormatter>()
           .First();
   }
   

2. Configure the input formatter:

   var builder = WebApplication.CreateBuilder(args);
   
   builder.Services.AddControllers(options =>
   {
       options.InputFormatters.Insert(0, GetJsonPatchInputFormatter());
   });
   

Usage

To define an action method for a JSON Patch in an API controller:

1. Annotate it with the HttpPatch attribute
2. Accept a JsonPatchDocument<TModel>
3. Call ApplyTo on the patch document to apply changes

For example:

[HttpPatch]
public IActionResult JsonPatchWithModelState(
    [FromBody] JsonPatchDocument<Customer> patchDoc)
{
    if (patchDoc is not null)
    {
        var customer = CreateCustomer();

        patchDoc.ApplyTo(customer, ModelState);

        if (!ModelState.IsValid)
        {
            return BadRequest(ModelState);
        }

        return new ObjectResult(customer);
    }
    else
    {
        return BadRequest(ModelState);
    }
}

In a real app, the code would retrieve the data from a store such as a database and update the database after applying the patch.

Additional Documentation

For additional documentation and examples, refer to the official documentation on JSON Patch in ASP.NET Core.

Feedback & Contributing

Microsoft.AspNetCore.JsonPatch is released as open-source under the MIT license. Bug reports and contributions are welcome at the GitHub repository.