JsonPatchSupport.AspNetCore

Overview

JsonPatchSupport.AspNetCore is a lightweight package that enables JSON Patch support in ASP.NET Core using the Newtonsoft.Json library, allowing simple partial updates with minimal configuration.

For more details, visit the related blog post: ASP.NET Core JSON Patch API Example (written in Traditional Chinese).

Installation

Install the package via .NET CLI:

dotnet add package JsonPatchSupport.AspNetCore

Alternatively, add a project reference to your ASP.NET Core application.

Usage

Register Services

Add the auto service registration extension in your service configuration:

// add using directive
using JsonPatchSupport.AspNetCore;

var builder = WebApplication.CreateBuilder(args);

// register service
builder.Services.AddJsonPatchSupport();

var app = builder.Build();

API Example

Below is an example of how to use JSON Patch in an API controller:

using Microsoft.AspNetCore.JsonPatch;
using Microsoft.AspNetCore.Mvc;


[ApiController]
[Route("api/[controller]")]
public class ProductController : ControllerBase
{
    [HttpPatch("{id}")]
    public IActionResult Patch([FromRoute] int id, [FromBody] JsonPatchDocument<ProductDto> patchDocument)
    {
        // Simulate getting the entity from a data source
        var product = new ProductDto
        {
            Name = "product1",
            Price = 10,
        };

        // Apply the patch to the product
        patchDocument.ApplyTo(product, ModelState);

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

        // Simulate saving the updated entity to a data source

        return Ok(product);
    }
}

public class ProductDto
{
    public string Name { get; set; }
    public int Price { get; set; }
}

Example JSON Patch document:

[
  {
    "op": "replace",
    "path": "/Name",
    "value": "NewProductName"
  },
  {
    "op": "replace",
    "path": "/Price",
    "value": "99"
  }
]

Example cURL request:

curl -X 'PATCH' \
  'http://localhost:5183/api/Product/1' \
  -H 'accept: */*' \
  -H 'Content-Type: application/json-patch+json' \
  -d '
[
  {
    "op": "replace",
    "path": "/Name",
    "value": "NewProductName"
  },
  {
    "op": "replace",
    "path": "/Price",
    "value": "99"
  }
]'

Expected response:

{
  "name": "NewProductName",
  "price": 99
}