GetEntities
(
Dictionary <String, Object> entityValueDictionary,
String entityName,
String entityChildName,
Boolean convertToLowerCase
)
{
Debug.Assert(entityValueDictionary != null);
Debug.Assert(!String.IsNullOrEmpty(entityName));
Debug.Assert(!String.IsNullOrEmpty(entityChildName));
List <String> entities = new List <String>();
Object entitiesAsObject;
if (
entityValueDictionary.TryGetValue(entityName, out entitiesAsObject)
&&
entitiesAsObject is Object[]
)
{
foreach (Object entityAsObject in ( Object [] )entitiesAsObject)
{
String childValue;
if (
entityAsObject is Dictionary <String, Object>
&&
TwitterJsonUtil.TryGetJsonValueFromDictionary(
(Dictionary <String, Object>)entityAsObject,
entityChildName, out childValue)
)
{
if (convertToLowerCase)
{
childValue = childValue.ToLower();
}
entities.Add(childValue);
}
}
}
return(entities.ToArray());
}
GetTwitterResponseAsString
(
Stream oStream
)
{
Debug.Assert(oStream != null);
AssertValid();
String sResponse = new StreamReader(oStream).ReadToEnd();
if (!TwitterJsonUtil.IsValidJson(sResponse))
{
// Twitter occasionally sends a partial response with truncated
// JSON. That would lead to an ArgumentException with the message
// "Unterminated string passed in" if parsing were attempted.
throw new InvalidJsonException(
"The text received from Twitter is not valid JSON.");
}
return(sResponse);
}
TryGetQueryParametersForNextSearchPage
(
Dictionary <String, Object> oResponseDictionary,
out String sQueryParametersForNextPage
)
{
Debug.Assert(oResponseDictionary != null);
AssertValid();
sQueryParametersForNextPage = null;
Dictionary <String, Object> oSearchMetadataDictionary =
(Dictionary <String, Object>)
oResponseDictionary["search_metadata"];
return(
oSearchMetadataDictionary != null
&&
TwitterJsonUtil.TryGetJsonValueFromDictionary(
oSearchMetadataDictionary, "next_results",
out sQueryParametersForNextPage)
);
}
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...
}
}
TryParseStatus
(
Dictionary <String, Object> statusValueDictionary,
out Int64 statusID,
out DateTime statusDateUtc,
out String screenName,
out String text,
out String rawStatusJson,
out Dictionary <String, Object> userValueDictionary
)
{
Debug.Assert(statusValueDictionary != null);
statusID = Int64.MinValue;
statusDateUtc = DateTime.MinValue;
screenName = null;
text = null;
rawStatusJson = null;
userValueDictionary = null;
String statusDateUtcString;
if (
!TwitterJsonUtil.TryGetJsonValueFromDictionary(
statusValueDictionary, "id", out statusID)
||
!TwitterJsonUtil.TryGetJsonValueFromDictionary(
statusValueDictionary, "created_at", out statusDateUtcString)
||
!TwitterDateParser.TryParseTwitterDate(statusDateUtcString,
out statusDateUtc)
||
!TwitterJsonUtil.TryGetJsonValueFromDictionary(
statusValueDictionary, "text", out text)
)
{
return(false);
}
const String UserKeyName = "user";
if (!statusValueDictionary.ContainsKey(UserKeyName))
{
// This has actually happened--Twitter occasionally sends a
// status without user information.
return(false);
}
userValueDictionary =
(Dictionary <String, Object>)statusValueDictionary[UserKeyName];
if (!TwitterJsonUtil.TryGetJsonValueFromDictionary(
userValueDictionary, "screen_name", out screenName))
{
return(false);
}
rawStatusJson = ValueDictionaryToRawJson(statusValueDictionary);
return(true);
}