public static IEnumerable <Tweet> StreamStatuses(TwitterConfig config, string keywords)
{
DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(typeof(Tweet));
var streamReader = ReadTweets(config, keywords);
while (true)
{
string line = null;
try { line = streamReader.ReadLine(); }
catch (Exception) { }
if (!string.IsNullOrWhiteSpace(line) && !line.StartsWith("{\"delete\""))
{
var result = (Tweet)jsonSerializer.ReadObject(new MemoryStream(Encoding.UTF8.GetBytes(line)));
result.RawJson = line;
yield return(result);
}
// Oops the Twitter has ended... or more likely some error have occurred.
// Reconnect to the twitter feed.
if (line == null)
{
streamReader = ReadTweets(config, keywords);
}
}
}
public static string getOAuthSignature(TwitterConfig config, string keywords, string oauth_nonce, string oauth_timestamp)
{
// Create Base oAuth String
var baseString = string.Format(
"oauth_consumer_key={0}" +
"&oauth_nonce={1}" +
"&oauth_signature_method={2}" +
"&oauth_timestamp={3}" +
"&oauth_token={4}" +
"&oauth_version={5}" +
"&track={6}",
config.twitterConsumerKey,
oauth_nonce,
config.oAuthSignatureMethod,
oauth_timestamp,
config.twitterAccessToken,
config.oAuthVersion,
Uri.EscapeDataString(keywords));
baseString = string.Concat("POST&", Uri.EscapeDataString(config.resourceUrl), "&", Uri.EscapeDataString(baseString));
// Create Composite Key
var compositeKey = string.Concat(Uri.EscapeDataString(config.twitterConsumerSecret), "&", Uri.EscapeDataString(config.twitterTokenSecret));
// Create oAuth Signature
string oauth_signature = string.Empty;
using (var hasher = new HMACSHA1(ASCIIEncoding.ASCII.GetBytes(compositeKey)))
{
oauth_signature = Convert.ToBase64String(hasher.ComputeHash(ASCIIEncoding.ASCII.GetBytes(baseString)));
}
return(oauth_signature);
}
public static TextReader ReadTweets(TwitterConfig config, string keywords)
{
// unique request details
var oauth_nonce = Convert.ToBase64String(new ASCIIEncoding().GetBytes(DateTime.Now.Ticks.ToString()));
var oauth_timestamp = Convert.ToInt64((DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc)).TotalSeconds).ToString();
var oauth_signature = Helpers.getOAuthSignature(config, keywords, oauth_nonce, oauth_timestamp);
// create the request header
var authHeader = string.Format(
"OAuth oauth_nonce=\"{0}\", oauth_signature_method=\"{1}\", " +
"oauth_timestamp=\"{2}\", oauth_consumer_key=\"{3}\", " +
"oauth_token=\"{4}\", oauth_signature=\"{5}\", " +
"oauth_version=\"{6}\"",
Uri.EscapeDataString(oauth_nonce),
Uri.EscapeDataString(config.oAuthSignatureMethod),
Uri.EscapeDataString(oauth_timestamp),
Uri.EscapeDataString(config.twitterConsumerKey),
Uri.EscapeDataString(config.twitterAccessToken),
Uri.EscapeDataString(oauth_signature),
Uri.EscapeDataString(config.oAuthVersion)
);
// make the request
ServicePointManager.Expect100Continue = false;
HttpWebRequest request = Helpers.getHttpWebRequest(config.resourceUrl + "?track=" + HttpUtility.UrlEncode(keywords), authHeader);
// bail out and retry after 5 seconds
var tresponse = request.GetResponseAsync();
if (tresponse.Wait(5000))
{
return(new StreamReader(tresponse.Result.GetResponseStream()));
}
else
{
request.Abort();
return(StreamReader.Null);
}
}
