/// <summary>
/// Constructor.</summary>
/// <param name="request">
/// The request to be used for the form data submission. This class automatically sets several fields which should not
/// be modified by the caller afterwards. These are: Method, ContentType. You MUST NOT call <see
/// cref="HttpWebRequest.GetRequestStream()"/> or <see cref="HttpWebRequest.GetResponse()"/> on this request. You may
/// modify request headers until the first call to an Add* method.</param>
public MultipartFormDataHelper(HttpWebRequest request)
{
if (request == null)
{
throw new ArgumentNullException(nameof(request));
}
_request = request;
var boundary = Rnd.NextBytes(15).ToHex();
_bytesBoundary = ("--" + boundary + "\r\n").ToUtf8();
_bytesBoundaryLast = ("--" + boundary + "--\r\n").ToUtf8();
_request.ContentType = "multipart/form-data; boundary=" + boundary;
_request.Method = "POST";
}
/// <summary>
/// Performs a POST request with the body consisting of a series of key-value arguments, encoded in the
/// <c>multipart/form-data</c> format.</summary>
/// <param name="url">
/// The URL of the request. If the URL does not begin with <c>http://</c> or <c>https://</c>, it is automatically
/// prepended with <see cref="RootUrl"/>.</param>
/// <param name="args">
/// The arguments to pass with the POST request. Null values are allowed and ignored.</param>
/// <returns>
/// The response received from the server.</returns>
/// <remarks>
/// Choose this format for requests that need to contain file uploads.</remarks>
/// <seealso cref="Post(string,HArg[])"/>
public HResponse PostFormdata(string url, params HArg[] args)
{
if (args == null)
{
args = new HArg[0];
}
var invalid = args.Where(a => a != null).FirstOrDefault(a => !a.Valid);
if (invalid != null)
{
throw new ArgumentException("args", "The argument with name '{0}' is not valid.".Fmt(invalid.Name));
}
string boundary = Rnd.NextBytes(20).ToHex();
var ms = new MemoryStream(300 + args.Where(a => a != null).Sum(a => 30 + a.Name.Length + (a.FileContent == null ? a.Value.Length : a.FileContent.Length)));
var sw = new StreamWriter(ms);
sw.AutoFlush = true;
foreach (var arg in args.Where(a => a != null))
{
if (arg.FileContent == null)
{
sw.WriteLine("--" + boundary);
sw.WriteLine(@"Content-Disposition: form-data; name=""" + arg.Name + @"""");
sw.WriteLine();
sw.WriteLine(arg.Value);
}
else
{
sw.WriteLine("--" + boundary);
sw.WriteLine(@"Content-Disposition: form-data; name=""" + arg.Name + @"""; filename=""" + arg.FileName + @"""");
sw.WriteLine(@"Content-Type: " + arg.FileContentType);
sw.WriteLine();
ms.Write(arg.FileContent);
sw.WriteLine();
}
}
sw.WriteLine("--" + boundary + "--");
return(Post(url, ms.ToArray(), "multipart/form-data; boundary=" + boundary));
}
