CODEWITHSUNDEEP
c#asp.net-mvcasp.net-core
Ondama papaoutai
Ondama papaoutai

Reputation: 77

Porting a class implementation from asp.net mvc to asp.net mvc core

I was trying to implement a subclass of ActionResult that will stream big JSON objects from a REST API, I found this solution on stack overflow but it seems like it's an implementation for asp.net MVC.

public class JsonStreamingResult : ActionResult
{
    private IEnumerable itemsToSerialize;

    public JsonStreamingResult(IEnumerable itemsToSerialize)
    {
        this.itemsToSerialize = itemsToSerialize;
    }

    public override void ExecuteResult(ActionContext context)
    {
        var response = context.HttpContext.Response;
        response.ContentType = "application/json";
        response.ContentEncoding = Encoding.UTF8;

        JsonSerializer serializer = new JsonSerializer();

        using (StreamWriter sw = new StreamWriter(response.OutputStream))
        using (JsonTextWriter writer = new JsonTextWriter(sw))
        {
            writer.WriteStartArray();
            foreach (object item in itemsToSerialize)
            {
                JObject obj = JObject.FromObject(item, serializer);
                obj.WriteTo(writer);
                writer.Flush();
            }
            writer.WriteEndArray();
        }
    }
}

But when I was in the process of porting this to asp.net core MVC I found that the response class does not have ContentEncoding and OutputStream properties.

Please, can anyone provide the required changes to port this class to asp.net core?

Thanks in advance.

Upvotes: 2

Views: 600

Answers (1)

Alexander
Alexander

Reputation: 9642

OutputStream - in ASP.NET Core HttpResponse contains Body property to which you can write a response. ContentEncoding - set encoding for StreamWriter since you manually write result to the response stream. In ASP.NET MVC HttpResponse.ContentEncoding were only used when you called HttpResponse.Write methods.

public class JsonStreamingResult : ActionResult
{
    private IEnumerable itemsToSerialize;

    public JsonStreamingResult(IEnumerable itemsToSerialize)
    {
        this.itemsToSerialize = itemsToSerialize;
    }

    public override void ExecuteResult(ActionContext context)
    {
        var response = context.HttpContext.Response;
        response.ContentType = "application/json";

        JsonSerializer serializer = new JsonSerializer();

        using (StreamWriter sw = new StreamWriter(response.Body, Encoding.UTF8))
        using (JsonTextWriter writer = new JsonTextWriter(sw))
        {
            writer.WriteStartArray();
            foreach (object item in itemsToSerialize)
            {
                JObject obj = JObject.FromObject(item, serializer);
                obj.WriteTo(writer);
                writer.Flush();
            }
            writer.WriteEndArray();
        }
    }
}

Update

According to source code, JsonResultExecutor internally does exactly what I've described, only difference is it parses encoding from ContentType.

Upvotes: 3

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