Custom JSON Formatters in ASP.NET Core with Newtonsoft.Json

This repository demonstrates how to add custom JSON formatters to an ASP.NET Core application. These formatters specifically target a single assembly and are based on the Newtonsoft.Json library. They provide fine-grained control over the serialization and deserialization process.

Why is this important?

In scenarios where we deal with classes with circular references and polymorphism (like in our 'Facade' assembly), standard serialization and deserialization can lead to issues.

We can use the PreserveReferencesHandling and TypeNameHandling settings of our JSON serializer to handle these situations. However, we might not want these settings to be applied globally. Our custom formatters come into play here.

How does it work?

We create and implement custom input and output formatters in ASP.NET Core to apply specific serialization and deserialization rules to a given assembly. In this case, we apply these rules to the 'Facade' assembly.

Here's an overview of the classes involved:

1. FacadeInputFormatter & FacadeOutputFormatter: These are the custom formatters that inherit from NewtonsoftJsonInputFormatter and NewtonsoftJsonOutputFormatter. They ensure their use is restricted to actions within the 'Facade' assembly.

2. NewtonsoftMvcOptionsRegistration: This class configures the MVC options to insert our custom formatters at the beginning of the formatter lists.