Return json with lower case first letter of property names

Question

I have LoginModel:

public class LoginModel : IData
{
    public string Email { get; set; }
    public string Password { get; set; }
}

and I have the Web api method

public IHttpActionResult Login([FromBody] LoginModel model)
{
    return this.Ok(model);
}

And it's return 200 and body:

{
    Email: "dfdf",
    Password: "dsfsdf"
}

But I want to get with lower first letter in property like

{
    email: "dfdf",
    password: "dsfsdf"
}

And I have Json contract resolver for correcting

public class FirstLowerContractResolver : DefaultContractResolver
{
    protected override string ResolvePropertyName(string propertyName)
    {
        if (string.IsNullOrWhiteSpace(propertyName))
            return string.Empty;

        return $"{char.ToLower(propertyName[0])}{propertyName.Substring(1)}";
    }
}

How I can apply this?

Answer 1

If your are using Newtonsoft.Json, you can add JsonProperties to your view model :

public class LoginModel : IData {      [JsonProperty(PropertyName = "email")]      public string Email {get;set;}       [JsonProperty(PropertyName = "password")]      public string Password {get;set;} } 

Answer 2

To force all json data returned from api to camel case it's easier to use Newtonsoft Json with the default camel case contract resolver.

Create a class like this one:

using Newtonsoft.Json.Serialization;  internal class JsonContentNegotiator : IContentNegotiator {     private readonly JsonMediaTypeFormatter _jsonFormatter;      public JsonContentNegotiator(JsonMediaTypeFormatter formatter)     {         _jsonFormatter = formatter;                   _jsonFormatter.SerializerSettings.ContractResolver =             new CamelCasePropertyNamesContractResolver();     }      public ContentNegotiationResult Negotiate(Type type, HttpRequestMessage request, IEnumerable<MediaTypeFormatter> formatters)     {         return new ContentNegotiationResult(_jsonFormatter, new MediaTypeHeaderValue("application/json"));     } } 

and set this during api configuration (at startup):

var jsonFormatter = new JsonMediaTypeFormatter(); httpConfiguration.Services.Replace(typeof(IContentNegotiator), new JsonContentNegotiator(jsonFormatter)); 

Answer 3

You can add the two following statement in the configuration of the web API or to the startup file

using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;

GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.Formatting = Formatting.Indented;

But it is very important to use the return Ok() method instead of return Json() otherwise; this will not work.

if you have to use Json method (and have no other choice) then see this answer https://stackoverflow.com/a/28960505/4390133