How to post to url and get bytes back using ServiceStack?

Question

I'm trying to post data to a URL and get byte array back using ServiceStack.

    byte[] pdf = await "https://some-url.com/that-expects-post/and-returns/pdf-file"
        .PostToUrlAsync(new
        {
            param1 = "aaa",
            param2 = 123
        },
        requestFilter: req =>
            req.Headers.Add("Cookie",
                cookies.Select(x => $"{x.Name}={x.Value}").Join(";")));

the request works and I get a PDF file back, but, in string format, not bytes. I tryed to save this string into file, but this didn't work.

How can I solve this?

Answer 1

Have a look at the HTTP Utils implementation in HttpUtils.HttpClient.cs to see how the different extension methods are implemented where they're just convenience wrappers around SendStringToUrl/Async and SendBytesToUrl/Async.

To receive bytes you'll need to one of the *Bytes convenience methods like PostBytesToUrlAsync, but they only accept a bytes Request Body which you'll need to construct yourself.

E.g. you can send the same Form Data request that PostToUrl APIs send with:

var formData = QueryStringSerializer.SerializeToString(new {
    param1 = "aaa",
    param2 = 123
}).ToUtf8Bytes();

var pdf = await url.PostBytesToUrlAsync(formData, 
    contentType: MimeTypes.FormUrlEncoded,
    requestFilter: req => req.Headers.Add("Cookie",
        cookies.Select(x => $"{x.Name}={x.Value}").Join(";")));