ASP.NET Web API partial response Json serialization

Question

I am implementing a Web API that supports partial response.

/api/users?fields=id,name,age

Given the class User

[JsonObject(         


        

Answer 1

Create your own IContractResolver to tell JSON.NET which properties need to be serialized. There's an example in official documentation you can take draw inspiration from.

Answer 2

You can also conditionally serialize a property by adding a boolean method with the same name as the property and then prefixed the method name with ShouldSerialize. The result of the method determines whether the property is serialized. If the method returns true then the property will be serialized, if it returns false and the property will be skipped.

public class Employee
{
  public string Name { get; set; }
  public Employee Manager { get; set; }

  public bool ShouldSerializeManager()
  {
      // don't serialize the Manager property if an employee is their own manager
      return (Manager != this);
  }
}

Answer 3

Just to add to the responses already here; I found a nuget package that does this for you

WebApi.PartialResponse

Git hub source code:
https://github.com/dotarj/PartialResponse

It essentially wraps the formatter discussed above, so that you only have to configure it like this:

GlobalConfiguration.Configuration.Formatters.Clear();
GlobalConfiguration.Configuration.Formatters.Add(new PartialJsonMediaTypeFormatter() { IgnoreCase = true });

Then, you can specify ?fields=<whatever> in your request, and it will return the model with only those fields specified.