A small helper library to allow deserialization (and serialization) of JSON fragments. Helpful for PATCH or partial PUT operations in web API projects.

Install the library via NuGet. All you need to do is manage your NuGet packages via Visual Studio or run

nuget install Partial.Newtonsoft.Json

in the package manager command line. Alternatively, you can install the library via the command line using the dotnet tooling.

⚠️⚠️ The namespace of this project is Newtonsoft.Json.Partial. ⚠️⚠️

The main class is called Part<T>. This class is a wrapper that should be used for deserializing objects with information about the used keys.

// The DTO
public class Employee
{
    [JsonProperty(PropertyName = "id")]
    public string Id { get; set; }

    [JsonProperty(PropertyName = "name")]
    public string Name { get; set; }

    [JsonProperty(PropertyName = "age")]
    public int Age { get; set; }
}

// The incoming JSON
var json = "{\"id\": 17, \"name\": \"Test\"}";

// Usually, we do this to obtain the deserialized object
var normalObj = JsonConvert.DeserializeObject<Employee>(json);

// Now we can also do this to obtain the deserialized object and more information
var partialObj = JsonConvert.DeserializeObject<Part<Employee>>(json);

Note that partialObj.Data is equal to normalObj, however, in partialObj we also have a Keys property.

Once we have a Part<T> object we can use it to get information to the used Keys or use one of the extension methods.

var partialObj = JsonConvert.DeserializeObject<Part<Employee>>(json);

if (partialObj.IsSet(m => m.Age))
{
    // Do something if Age has been set
}

Alternatively, we can also supply a callback action.

var partialObj = JsonConvert.DeserializeObject<Part<Employee>>(json);

partialObj.IsSet(m => m.Age, value =>
{
    // Do something with the supplied value of Age
});

It is also possible to perform some validation on the supplied JSON object to verify that no "illegal" properties have been specified:

var partialObj = JsonConvert.DeserializeObject<Part<Employee>>(json);

// Perform validation of the partial object
var isValid = partialObj.Validate();

In addition to the usual JsonProperty, JsonIgnore, etc. attributes there is also the JsonNoPartial attribute. It specifies that in context of partial deserialization that property must not be set.

MIT License (MIT). For more information see LICENSE file.