EnumerateJsonValues
(
String url,
String jsonName,
Int32 maximumValues,
Boolean skipMostPage1Errors,
RequestStatistics requestStatistics,
ReportProgressHandler reportProgressHandler,
CheckCancellationPendingHandler checkCancellationPendingHandler
)
{
// Note:
//
// The logic in this method is similar to the logic in
// EnumerateSearchStatuses(). In fact, at one time all enumeration was
// done through this EnumerateJsonValues() method.
// EnumerateSearchStatuses() was created only when version 1.1 of the
// Twitter API introduced yet another paging scheme, one that differs
// from the cursor scheme that this method handles.
//
// A possible work item is to recombine the two methods into one,
// possibly by using a delegate to handle the different paging schemes.
Debug.Assert(!String.IsNullOrEmpty(url));
Debug.Assert(maximumValues > 0);
Debug.Assert(requestStatistics != null);
AssertValid();
Int32 iPage = 1;
String sCursor = null;
Int32 iObjectsEnumerated = 0;
while (true)
{
if (iPage > 1)
{
HttpSocialNetworkUtil.ReportProgress(reportProgressHandler,
"Getting page {0}."
,
iPage
);
}
String sUrlWithCursor = AppendCursorToUrl(url, sCursor);
Dictionary <String, Object> oValueDictionary = null;
Object [] aoObjectsThisPage;
try
{
Object oDeserializedTwitterResponse =
(new JavaScriptSerializer()).DeserializeObject(
GetTwitterResponseAsString(sUrlWithCursor,
requestStatistics, reportProgressHandler,
checkCancellationPendingHandler));
Object oObjectsThisPageAsObject;
if (jsonName == null)
{
// The top level of the Json response contains an array of
// objects this method will enumerate.
oObjectsThisPageAsObject = oDeserializedTwitterResponse;
}
else
{
// The top level of the Json response contains a set of
// name/value pairs. The value for the specified name is
// the array of objects this method will enumerate.
oValueDictionary = (Dictionary <String, Object>)
oDeserializedTwitterResponse;
oObjectsThisPageAsObject = oValueDictionary[jsonName];
}
aoObjectsThisPage = ( Object [] )oObjectsThisPageAsObject;
}
catch (Exception oException)
{
// Rethrow the exception if appropriate.
TwitterUtil.OnExceptionWhileEnumeratingJsonValues(
oException, iPage, skipMostPage1Errors);
// Otherwise, just halt the enumeration.
yield break;
}
Int32 iObjectsThisPage = aoObjectsThisPage.Length;
if (iObjectsThisPage == 0)
{
yield break;
}
for (Int32 i = 0; i < iObjectsThisPage; i++)
{
yield return(aoObjectsThisPage[i]);
iObjectsEnumerated++;
if (iObjectsEnumerated == maximumValues)
{
yield break;
}
}
iPage++;
// When the top level of the Json response contains a set of
// name/value pairs, a next_cursor_str value of "0" means "end of
// data."
if (
oValueDictionary == null
||
!TwitterJsonUtil.TryGetJsonValueFromDictionary(
oValueDictionary, "next_cursor_str", out sCursor)
||
sCursor == "0"
)
{
yield break;
}
// Get the next page...
}
}
BeforeGetNetwork()
{
AssertValid();
// TwitterAccessToken caches the access token it reads from disk. Make
// sure the latest access token is read.
TwitterAccessToken oTwitterAccessToken = new TwitterAccessToken();
// A network should never be requested if the access token hasn't been
// saved yet.
String sToken, sSecret;
if ( !oTwitterAccessToken.TryLoad(out sToken, out sSecret) )
{
throw new Exception("Twitter access token not set.");
}
m_oTwitterUtil = new TwitterUtil(sToken, sSecret,
HttpNetworkAnalyzerBase.UserAgent,
HttpNetworkAnalyzerBase.HttpWebRequestTimeoutMs);
}