public IHttpActionResult Post([FromBody] string html) { if (string.IsNullOrWhiteSpace(html)) { ModelState.AddModelError("html", "Cannot generate pdf from nothing"); return(BadRequest(ModelState)); } var pdfData = _service.CreatePdfFromHtml(html); if (pdfData.LongLength <= 0) { ModelState.AddModelError("pdf", "Could not generate a pdf correctly"); return(BadRequest(ModelState)); } return(Ok(pdfData)); }