JsonPatch学习

网址 http://jsonpatch.com/

参考资料   https://docs.microsoft.com/zh-cn/aspnet/core/web-api/jsonpatch?view=aspnetcore-3.1

      jsonpatch 个人感觉就是简化修改接口，就像给接口传个命令一样， replace Age 30；replace 就像命令， Age 就是参数，要修改的字段， 30 就是具体修改的值，jsonpatch 是通过json的方式来传递命令的，基本就是对json的 操作，增改删，

支持的语言也比较广泛，js 用法 http://jsonpatchjs.com/

例如 我们在QQ 中设置资料的时候， 是没有保存按钮的，选一个 或者编辑 都会 更新的，这种功能，我们不可能每次小改动就传递一个很大的实体去服务端修改，jsonpatch 就解决了这个问题

[{"op":"replace","path":"isopen","value":"true"}]  这个就即搞定，

页面是没有保存按钮的，但是点击复选框等都会保存我们的操作。

安装2个包
Microsoft.AspNetCore.JsonPatch
Microsoft.AspNetCore.Mvc.NewtonsoftJson
注册
services.AddControllers().AddNewtonsoftJson();

准备实体类和API接口

[ApiController]
    [Route("jsonpatch")]
    public class JsonPatchController : ControllerBase
    {
        public static List<User> _list;
        private readonly ILogger<JsonPatchController> _logger;

        public JsonPatchController(ILogger<JsonPatchController> logger)
        {
            _logger = logger;
            _list = new List<User>();

            _list.Add(new User { Address=new List<Address> { new Address { City="广州", Group="一组" } }, Id=1, Name="jet1" });
            _list.Add(new User { Address = new List<Address> { new Address { City = "深圳", Group = "2组" } }, Id = 2, Name = "jet2" });
            _list.Add(new User { Address = new List<Address> { new Address { City = "西安", Group = "3组" } }, Id = 3, Name = "jet3" });


        }
        [Route("[action]/{id}")]
        [HttpPatch]
        public IActionResult UserOperation(int id, [FromBody] JsonPatchDocument<User> userDoc)
        {
            if (userDoc != null)
            {
                var user =_list.Where(x=>x.Id== id).FirstOrDefault();
                userDoc.ApplyTo(user, ModelState);
                if (!ModelState.IsValid)
                {
                    return BadRequest(ModelState);
                }
                 //context.savechange()
                return new ObjectResult(user);
            }
            else
            {
                return BadRequest(ModelState);
            }
        }
       

    }


    public class User
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public List<Address> Address { get; set; }
    }
    public class Address
    {
        public string City { get; set; }
        public string Group { get; set; }
    }

postman 请求， Content-Type  ：application/json-patch+json

add

[
    {
        "op": "add",
        "path": "/Address/-",
        "value": {
            "City":"咸阳"
        }
    },
     {
        "op": "add",
        "path": "/Address/-",
        "value": {
            "City":"宝鸡"
        }
    }
   
]

remove

[
    {
        "op": "remove",
        "path": "/Address/",
        "value": {
            "City":"广州"
        }
    }
   
]

 replace

[
    {
        "op": "replace",
        "path": "/Address/-",
        "value": {
            "City":"湛江"
        }
    }
   
]

 移动操作  将城市移动到了user name

[
    {
        "op": "move",
        "from":"/Address/0/City",
        "path": "/Name"
    }
   
]

还有  copy   test

test 操作通常用于在发生并发冲突时阻止更新。