Using NewtonSoft JSON

To avoid version conflicts with Newtonsoft.Json, EntityGraphQL has no reference to it and hence doesn't know what to do if it hits a JToken or JObject.

If you are not using EntityGraphQL.AspNet and are trying to deserialize incoming JSON into the QueryRequest and you have objects in the variables field Newtonsoft.Json will deserialize the incoming JSON objects into the variables dictionary as JObject/JToken types and EntityGraphQL doesn't know what to do with them when trying to mapping them to the field arguments.

Note many JSON libraries will convert sub objects/arrays/etc into their own custom types when dealing with a Dictionary<string, object>. This can be used as an example to build other converters.

You can tell EntityGraphQL how to convert types when it is mapping incoming data classes/arguments using the AddCustomTypeConverter(new MyICustomTypeConverter()) on the schema provider.

Here is an example to use this to handle Newtonsoft.Json types:

internal class JObjectTypeConverter : ICustomTypeConverter
{
    public Type Type => typeof(JObject);

    public object ChangeType(object value, Type toType, ISchemaProvider schema)
    {
        return ((JObject)value).ToObject(toType);
    }
}

internal class JTokenTypeConverter : ICustomTypeConverter
{
    public Type Type => typeof(JToken);

    public object ChangeType(object value, Type toType, ISchemaProvider schema)
    {
        return ((JToken)value).ToObject(toType);
    }
}

internal class JValueTypeConverter : ICustomTypeConverter
{
    public Type Type => typeof(JValue);

    public object ChangeType(object value, Type toType, ISchemaProvider schema)
    {
        return ((JValue)value).ToString();
    }
}

// Where you build schema

schema.AddCustomTypeConverter(new JObjectTypeConverter());
schema.AddCustomTypeConverter(new JTokenTypeConverter());
schema.AddCustomTypeConverter(new JValueTypeConverter());

Now EntityGraphQL can convert JObject, JToken & JValue types to classes/types using your version of Newtonsoft.Json. You can use ICustomTypeConverter to handle any customer conversion.