With Json.NET, is there a way to find out what JSON type (array, object, string, integer etc.) that a given .NET type (or actually a MemberInfo) will be serialized to?
http://www.newtonsoft.com/json/help/html/serializationguide.htm
The documenation above gives a pretty good idea, but is there a public API in Json.NET I can use? Ideally it would also take into account any custom attributes that would affect serialization (like JsonObjectAttribute etc)
For what you need, the most appropriate solution is to use JSON schemas. JSON.NET has support for them:
http://www.newtonsoft.com/jsonschema
And one of the features is exactly what you need:
Generate JSON Schemas Generate JSON Schemas automatically from your existing .NET types.
from its home page.
There are examples on its documentation., like this:
public class Person
{
public string Name { get; set; }
public int Age { get; set; }
}
JSchemaGenerator generator = new JSchemaGenerator();
JSchema schema = generator.Generate(typeof(Person));
// {
// "type": "object",
// "properties": {
// "Name": {
// "type": [ "string", "null" ]
// },
// "Age": { "type": "integer" }
// },
// "required": [ "Name", "Age" ]
// }
When I wrote the answer I didn't realized that you need a license for commercial use. This is the license link, included in the comment by the OP, @Oskar.
Doing your own implementatin is really complex because the generated JSON depends on JSON.NET configuration, which can include from simple attributes to custom (de)serializers, and several other configurations. So, "predicting" what JSON will be generated by JSON.NET is really hard to do. The easiest way would be:
Doing this is very difficult, both instancing a valid sample .NET object, and analyzing the resulting JSON. To make the last step easier you could create a .NET object back from the JSON, and analyze it with Reflection. And caching the results of these analyses to avoid too much use of Reflection, which is quite slow.
Unfortunately, there isn't still a JavaScript language service in Visual Studio, but it will be available in the next release. This would make it much easier to analyze the resulting Javascript object. Rememeber that JSON is a literal JavaScript object, which can be easyly instanced, but in the JavaScript domain.
