I'm trying to create an attribute that will serialize data return from an action differently
public override void OnActionExecuted(HttpActionExecutedContext filterContext)
{
var content = (filterContext.Response.Content as ObjectContent);
if (content == null)
{
return;
}
if (content.ObjectType.IsGenericType
&& content.ObjectType.GetGenericTypeDefinition() == typeof (Page<>))
{
var pageObject = (content.Value as IPage);
var jsonFormatterRule = new JsonFormatterRule();
var pageJson = JsonConvert.SerializeObject(pageObject.ItemsArray,
jsonFormatterRule.GetPascalCasedSettings());
//How do I set the content that \/ doesn't compile?
//filterContext.Response.Content = pageJson;
}
}
This is the JsonFormatterRules incase anyone wanted to see them.
public JsonSerializerSettings GetDefaultSettings()
{
var settings = new JsonSerializerSettings()
{
Formatting = Formatting.Indented,
ContractResolver = new CamelCasePropertyNamesContractResolver(),
DateTimeZoneHandling = DateTimeZoneHandling.RoundtripKind,
};
settings.Converters.AddRange(defaultConfiguredConverters);
return settings;
}
public JsonSerializerSettings GetPascalCasedSettings()
{
var settings = this.GetDefaultSettings();
settings.ContractResolver = new DefaultContractResolver();
return settings;
}
How can I Set the Content From On Action Executed? I cannot change the default serializer to the DefaultContract Globally because it could threading issues.
Also I'd prefer not to have to create a new response and copy over the Headers from the old one that seems like over kill.
One way to do this would be to define a custom formatter.
First, define your attribute:
[AttributeUsage(AttributeTargets.Class)]
public sealed class SpecialSerializeAttribute : Attribute
{
}
Now create a formatter that will find the attribute:
public class SpecialSerializeFormatter : MediaTypeFormatter
{
public SpecialSerializeFormatter()
{
//You can add any other supported types here.
this.SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/json"));
}
public override bool CanReadType(Type type)
{
//you can just return false if you don't want to read any differently than your default way
//if you return true here, you should override the ReadFromStreamAsync method to do custom deserialize
return type.IsDefined(typeof(SpecialSerializeAttribute), true));
}
public override bool CanWriteType(Type type)
{
return type.IsDefined(typeof(SpecialSerializeAttribute), true));
}
public override async Task WriteToStreamAsync(Type type, object value, Stream writeStream, HttpContent content,
TransportContext transportContext)
{
//value will be your object that you want to serialize
//add any custom serialize settings here
var json = JsonConvert.SerializeObject(value);
//Use the right encoding for your application here
var byteArray = Encoding.UTF8.GetBytes(json);
await writeStream.WriteAsync(byteArray, 0, byteArray.Length);
}
}
Register the formatter in you WebApiConfig.cs
You can also build a formatter for each type directly and then you don't have to do the Attribute. Just change your CanRead and CanWrite methods. I find basing these of the direct Type's gives better results since it's not such a generic formatter and you may need to apply custom logic based on the type, but the above answer should get you what you need.