TryGetXmlDocument
(
String sUrl,
RequestStatistics oRequestStatistics,
out XmlDocument oXmlDocument,
out XmlNamespaceManager oXmlNamespaceManager
)
{
Debug.Assert( !String.IsNullOrEmpty(sUrl) );
Debug.Assert(oRequestStatistics != null);
AssertValid();
oXmlDocument = null;
oXmlNamespaceManager = null;
try
{
oXmlDocument = GetXmlDocument(sUrl, oRequestStatistics,
out oXmlNamespaceManager);
return (true);
}
catch (Exception oException)
{
if ( !HttpSocialNetworkUtil.ExceptionIsWebOrXml(oException))
{
throw oException;
}
return (false);
}
}
TryGetXmlDocument
(
String sUrl,
RequestStatistics oRequestStatistics,
out XmlDocument oXmlDocument
)
{
Debug.Assert(!String.IsNullOrEmpty(sUrl));
Debug.Assert(oRequestStatistics != null);
AssertValid();
oXmlDocument = null;
try
{
oXmlDocument = GetXmlDocument(sUrl, oRequestStatistics);
return(true);
}
catch (Exception oException)
{
// Note: Because a FlickrException is also a WebException, the
// following logic will cause false to be returned for a
// FlickrException.
if (!HttpSocialNetworkUtil.ExceptionIsWebOrXml(oException))
{
throw oException;
}
return(false);
}
}
WebExceptionIsDueToRateLimit
(
WebException webException
)
{
Debug.Assert(webException != null);
// Starting with version 1.1 of the Twitter API, a single HTTP status
// code (429, "rate limit exceeded") is used for all rate-limit
// responses.
return(HttpSocialNetworkUtil.WebExceptionHasHttpStatusCode(
webException, (HttpStatusCode)429));
}
TryGetUserValueDictionary
(
String sScreenName,
RequestStatistics oRequestStatistics,
Boolean bIgnoreWebAndJsonExceptions,
out Dictionary <String, Object> oUserValueDictionary
)
{
Debug.Assert(!String.IsNullOrEmpty(sScreenName));
Debug.Assert(oRequestStatistics != null);
AssertValid();
oUserValueDictionary = null;
String sUrl = String.Format(
"{0}users/show.json?screen_name={1}&{2}"
,
TwitterApiUrls.Rest,
TwitterUtil.EncodeUrlParameter(sScreenName),
TwitterApiUrlParameters.IncludeEntities
);
ReportProgress(String.Format(
"Getting information about \"{0}\"."
,
sScreenName
));
try
{
oUserValueDictionary = (Dictionary <String, Object>)
(new JavaScriptSerializer()).DeserializeObject(
GetTwitterResponseAsString(sUrl, oRequestStatistics));
return(true);
}
catch (Exception oException)
{
if (!HttpSocialNetworkUtil.ExceptionIsWebOrJson(oException) ||
!bIgnoreWebAndJsonExceptions)
{
throw oException;
}
return(false);
}
}
OnExceptionWhileEnumeratingJsonValues
(
Exception exception,
Int32 iPage,
Boolean bSkipMostPage1Errors
)
{
Debug.Assert(exception != null);
Debug.Assert(iPage > 0);
if (!HttpSocialNetworkUtil.ExceptionIsWebOrJson(exception))
{
// This is an unknown exception.
throw (exception);
}
if (
exception is WebException
&&
WebExceptionIsDueToRateLimit((WebException)exception)
)
{
throw (exception);
}
else if (iPage == 1)
{
if (bSkipMostPage1Errors)
{
return;
}
else
{
throw (exception);
}
}
else
{
// Always skip non-rate-limit errors on page 2 and above.
return;
}
}
/// <summary>
/// Web Request Wrapper
/// </summary>
/// <param name="method">Http Method</param>
/// <param name="url">Full url to the web resource</param>
/// <param name="postData">Data to post in querystring format</param>
/// <returns>The web server response.</returns>
public string WebRequest(Method method, string url, string postData)
{
HttpWebRequest webRequest = null;
StreamWriter requestWriter = null;
string responseData = "";
webRequest = HttpSocialNetworkUtil.CreateHttpWebRequest(
url, _userAgent, _timeoutMs);
webRequest.Method = method.ToString();
webRequest.ServicePoint.Expect100Continue = false;
if (method == Method.POST)
{
webRequest.ContentType = "application/x-www-form-urlencoded";
//POST the data.
requestWriter = new StreamWriter(webRequest.GetRequestStream());
try
{
requestWriter.Write(postData);
}
catch
{
throw;
}
finally
{
requestWriter.Close();
requestWriter = null;
}
}
responseData = WebResponseGet(webRequest);
webRequest = null;
return(responseData);
}
GetXmlDocumentWithRetries
(
String sUrl,
HttpStatusCode [] aeHttpStatusCodesToFailImmediately,
RequestStatistics oRequestStatistics
)
{
Debug.Assert(!String.IsNullOrEmpty(sUrl));
Debug.Assert(oRequestStatistics != null);
AssertValid();
Stream oStream = null;
try
{
oStream =
HttpSocialNetworkUtil.GetHttpWebResponseStreamWithRetries(
sUrl, aeHttpStatusCodesToFailImmediately,
oRequestStatistics, UserAgent, HttpWebRequestTimeoutMs,
new ReportProgressHandler(this.ReportProgress),
new CheckCancellationPendingHandler(
this.CheckCancellationPending)
);
XmlDocument oXmlDocument = new XmlDocument();
oXmlDocument.Load(oStream);
return(oXmlDocument);
}
finally
{
if (oStream != null)
{
oStream.Close();
}
}
}
GetRelatedTagsRecursive
(
String sTag,
WhatToInclude eWhatToInclude,
NetworkLevel eNetworkLevel,
String sApiKey,
Int32 iRecursionLevel,
GraphMLXmlDocument oGraphMLXmlDocument,
Dictionary <String, XmlNode> oTagDictionary,
RequestStatistics oRequestStatistics
)
{
Debug.Assert(!String.IsNullOrEmpty(sTag));
Debug.Assert(eNetworkLevel == NetworkLevel.One ||
eNetworkLevel == NetworkLevel.OnePointFive ||
eNetworkLevel == NetworkLevel.Two);
Debug.Assert(!String.IsNullOrEmpty(sApiKey));
Debug.Assert(iRecursionLevel == 1 || iRecursionLevel == 2);
Debug.Assert(oGraphMLXmlDocument != null);
Debug.Assert(oTagDictionary != null);
Debug.Assert(oRequestStatistics != null);
AssertValid();
/*
* Here is what this method should do, based on the eNetworkLevel and
* iRecursionLevel parameters.
*
* eNetworkLevel
*
|One | OnePointFive | Two
* ---|------------------| ------------------| -----------------
* i 1 |Add all vertices. | Add all vertices. | Add all vertices.
* R | | |
* e |Add all edges. | Add all edges. | Add all edges.
* c | | |
* u |Do not recurse. | Recurse. | Recurse.
* r | | |
* s ---|------------------|-------------------|------------------
* i 2 |Impossible. | Do not add | Add all vertices.
* o | | vertices. |
* n | | |
* L | | Add edges only if | Add all edges.
* e | | vertices are |
* v | | already included. |
* e | | |
* l | | Do not recurse. | Do not recurse.
| | |
| ---|------------------|-------------------|------------------
*/
Boolean bNeedToRecurse = GetNeedToRecurse(eNetworkLevel,
iRecursionLevel);
Boolean bNeedToAppendVertices = GetNeedToAppendVertices(
eNetworkLevel, iRecursionLevel);
ReportProgress("Getting tags related to \"" + sTag + "\".");
String sUrl = GetFlickrMethodUrl("flickr.tags.getRelated", sApiKey,
"&tag=" + UrlUtil.EncodeUrlParameter(sTag));
XmlDocument oXmlDocument;
try
{
oXmlDocument = GetXmlDocument(sUrl, oRequestStatistics);
}
catch (Exception oException)
{
// If the exception is not a WebException or XmlException, or if
// none of the network has been obtained yet, throw the exception.
if (!HttpSocialNetworkUtil.ExceptionIsWebOrXml(oException) ||
!oGraphMLXmlDocument.HasVertexXmlNode)
{
throw oException;
}
return;
}
// The document consists of a single "tags" node with zero or more
// "tag" child nodes.
String sOtherTag = null;
XmlNodeList oTagNodes = oXmlDocument.DocumentElement.SelectNodes(
"tags/tag");
if (oTagNodes.Count > 0)
{
AppendVertexXmlNode(sTag, oGraphMLXmlDocument, oTagDictionary);
}
foreach (XmlNode oTagNode in oTagNodes)
{
sOtherTag = XmlUtil2.SelectRequiredSingleNodeAsString(oTagNode,
"text()", null);
if (bNeedToAppendVertices)
{
AppendVertexXmlNode(sOtherTag, oGraphMLXmlDocument,
oTagDictionary);
}
if (bNeedToAppendVertices ||
oTagDictionary.ContainsKey(sOtherTag))
{
oGraphMLXmlDocument.AppendEdgeXmlNode(sTag, sOtherTag);
}
}
if (bNeedToRecurse)
{
foreach (XmlNode oTagNode in oTagNodes)
{
sOtherTag = XmlUtil2.SelectRequiredSingleNodeAsString(oTagNode,
"text()", null);
GetRelatedTagsRecursive(sOtherTag, eWhatToInclude,
eNetworkLevel, sApiKey, 2, oGraphMLXmlDocument,
oTagDictionary, oRequestStatistics);
}
}
}
EnumerateXmlNodes
(
String sUrl,
String sXPath,
Int32 iMaximumXmlNodes,
Boolean bSkipMostPage1Errors,
RequestStatistics oRequestStatistics
)
{
Debug.Assert( !String.IsNullOrEmpty(sUrl) );
Debug.Assert( !String.IsNullOrEmpty(sXPath) );
Debug.Assert(iMaximumXmlNodes > 0);
Debug.Assert(oRequestStatistics != null);
AssertValid();
Int32 iStartIndex = 1;
Int32 iMaxResults = 50;
Int32 iXmlNodesEnumerated = 0;
while (true)
{
if (iStartIndex > 1)
{
ReportProgress("Getting page starting with item "
+ iStartIndex + ".");
}
String sUrlWithPagination = String.Format(
"{0}{1}start-index={2}&max-results={3}"
,
sUrl,
sUrl.IndexOf('?') == -1 ? '?' : '&',
iStartIndex,
iMaxResults
);
XmlDocument oXmlDocument;
XmlNamespaceManager oXmlNamespaceManager;
try
{
oXmlDocument = GetXmlDocument(sUrlWithPagination,
oRequestStatistics, out oXmlNamespaceManager);
}
catch (Exception oException)
{
if (!HttpSocialNetworkUtil.ExceptionIsWebOrXml(oException))
{
throw oException;
}
if (iStartIndex > 1 || bSkipMostPage1Errors)
{
// Always skip errors on page 2 and above.
yield break;
}
throw (oException);
}
XmlNodeList oXmlNodesThisPage = oXmlDocument.SelectNodes(sXPath,
oXmlNamespaceManager);
Int32 iXmlNodesThisPage = oXmlNodesThisPage.Count;
if (iXmlNodesThisPage == 0)
{
yield break;
}
for (Int32 i = 0; i < iXmlNodesThisPage; i++)
{
yield return ( oXmlNodesThisPage[i] );
iXmlNodesEnumerated++;
if (iXmlNodesEnumerated == iMaximumXmlNodes)
{
yield break;
}
}
// The next page, if there is one, is obtained from a link tag that
// looks something like this:
//
// <link rel="next" ... href="http://gdata.youtube.com/feeds/...?
// start-index=26&max-results=25"/>
String sHRef;
if ( !XmlUtil2.TrySelectSingleNodeAsString(oXmlDocument,
"a:feed/a:link[@rel='next']/@href", oXmlNamespaceManager,
out sHRef) )
{
yield break;
}
const String Pattern = @"start-index=(?<NextStartIndex>\d+)";
Regex oRegex = new Regex(Pattern);
Match oMatch = oRegex.Match(sHRef);
if (!oMatch.Success
||
!MathUtil.TryParseCultureInvariantInt32(
oMatch.Groups["NextStartIndex"].Value, out iStartIndex)
)
{
yield break;
}
// Get the next page...
}
}
EnumerateSearchStatuses
(
String searchTerm,
Int32 maximumStatuses,
RequestStatistics requestStatistics,
ReportProgressHandler reportProgressHandler,
CheckCancellationPendingHandler checkCancellationPendingHandler
)
{
Debug.Assert(!String.IsNullOrEmpty(searchTerm));
Debug.Assert(maximumStatuses > 0);
Debug.Assert(maximumStatuses != Int32.MaxValue);
Debug.Assert(requestStatistics != null);
AssertValid();
Int32 iPage = 1;
Int32 iStatusesEnumerated = 0;
String sQueryParametersForNextPage = null;
while (true)
{
if (iPage > 1)
{
HttpSocialNetworkUtil.ReportProgress(reportProgressHandler,
"Getting page {0}."
,
iPage
);
}
Dictionary <String, Object> oResponseDictionary = null;
Object [] aoStatusesThisPage;
String sUrl = GetSearchUrl(searchTerm,
sQueryParametersForNextPage);
try
{
Object oDeserializedTwitterResponse =
(new JavaScriptSerializer()).DeserializeObject(
GetTwitterResponseAsString(
sUrl, requestStatistics, reportProgressHandler,
checkCancellationPendingHandler));
// The top level of the Json response contains a set of
// name/value pairs. The value for the "statuses" name is the
// array of objects this method will enumerate.
oResponseDictionary = (Dictionary <String, Object>)
oDeserializedTwitterResponse;
aoStatusesThisPage =
( Object [] )oResponseDictionary["statuses"];
}
catch (Exception oException)
{
// Rethrow the exception if appropriate.
OnExceptionWhileEnumeratingJsonValues(oException, iPage,
false);
// Otherwise, just halt the enumeration.
yield break;
}
Int32 iObjectsThisPage = aoStatusesThisPage.Length;
if (iObjectsThisPage == 0)
{
yield break;
}
for (Int32 i = 0; i < iObjectsThisPage; i++)
{
yield return(
(Dictionary <String, Object>)aoStatusesThisPage[i]);
iStatusesEnumerated++;
if (iStatusesEnumerated == maximumStatuses)
{
yield break;
}
}
iPage++;
if (!TryGetQueryParametersForNextSearchPage(oResponseDictionary,
out sQueryParametersForNextPage))
{
yield break;
}
// Get the next page...
}
}
GetTwitterResponseAsString
(
String url,
RequestStatistics requestStatistics,
ReportProgressHandler reportProgressHandler,
CheckCancellationPendingHandler checkCancellationPendingHandler
)
{
Debug.Assert(!String.IsNullOrEmpty(url));
Debug.Assert(requestStatistics != null);
AssertValid();
Int32 iRateLimitPauses = 0;
Int32 iInvalidJsonRepeats = 0;
const Int32 MaximumInvalidJsonRepeats = 3;
while (true)
{
// Add the required authorization information to the URL.
//
// Note: Don't do this outside the while (true) loop. The
// authorization information includes a timestamp that will
// probably expire if the code within the catch block pauses.
oAuthTwitter oAuthTwitter = new oAuthTwitter(
m_UserAgent, m_TimeoutMs);
oAuthTwitter.Token = m_TwitterAccessToken;
oAuthTwitter.TokenSecret = m_TwitterAccessTokenSecret;
String sAuthorizedUrl, sAuthorizedPostData;
oAuthTwitter.ConstructAuthWebRequest(oAuthTwitter.Method.GET,
url, String.Empty, out sAuthorizedUrl,
out sAuthorizedPostData);
url = sAuthorizedUrl;
Stream oStream = null;
try
{
oStream =
HttpSocialNetworkUtil.GetHttpWebResponseStreamWithRetries(
url, HttpStatusCodesToFailImmediately,
requestStatistics, m_UserAgent, m_TimeoutMs,
reportProgressHandler, checkCancellationPendingHandler);
return(GetTwitterResponseAsString(oStream));
}
catch (InvalidJsonException oInvalidJsonException)
{
iInvalidJsonRepeats++;
if (iInvalidJsonRepeats > MaximumInvalidJsonRepeats)
{
throw oInvalidJsonException;
}
HttpSocialNetworkUtil.ReportProgress(reportProgressHandler,
"Received invalid JSON from Twitter. Trying again."
);
}
catch (WebException oWebException)
{
if (
!WebExceptionIsDueToRateLimit(oWebException)
||
iRateLimitPauses > 0
)
{
throw;
}
// Twitter rate limits have kicked in. Pause and try again.
iRateLimitPauses++;
Int32 iRateLimitPauseMs = GetRateLimitPauseMs(oWebException);
DateTime oWakeUpTime = DateTime.Now.AddMilliseconds(
iRateLimitPauseMs);
HttpSocialNetworkUtil.ReportProgress(reportProgressHandler,
"Reached Twitter rate limits. Pausing until {0}."
,
oWakeUpTime.ToLongTimeString()
);
// Don't pause in one large interval, which would prevent
// cancellation.
const Int32 SleepCycleDurationMs = 1000;
Int32 iSleepCycles = (Int32)Math.Ceiling(
(Double)iRateLimitPauseMs / SleepCycleDurationMs);
for (Int32 i = 0; i < iSleepCycles; i++)
{
if (checkCancellationPendingHandler != null)
{
checkCancellationPendingHandler();
}
System.Threading.Thread.Sleep(SleepCycleDurationMs);
}
}
finally
{
if (oStream != null)
{
oStream.Close();
}
}
}
}
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...
}
}
EnumerateUserValueDictionaries
(
String [] userIDsOrScreenNames,
Boolean userIDsSpecified,
RequestStatistics requestStatistics,
ReportProgressHandler reportProgressHandler,
CheckCancellationPendingHandler checkCancellationPendingHandler
)
{
Debug.Assert(userIDsOrScreenNames != null);
Debug.Assert(requestStatistics != null);
AssertValid();
// We'll use Twitter's users/lookup API, which gets extended
// information for up to 100 users in one call.
Int32 iUsers = userIDsOrScreenNames.Length;
Int32 iUsersProcessed = 0;
Int32 iCalls = 0;
while (iUsersProcessed < iUsers)
{
// For each call, ask for information about as many users as
// possible until either 100 is reached or the URL reaches an
// arbitrary maximum length. Twitter recommends using a POST here
// (without specifying why), but it would require revising the
// base-class HTTP calls and isn't worth the trouble.
Int32 iUsersProcessedThisCall = 0;
StringBuilder oUrl = new StringBuilder();
oUrl.AppendFormat(
"{0}users/lookup.json?{1}&{2}="
,
TwitterApiUrls.Rest,
TwitterApiUrlParameters.IncludeEntities,
userIDsSpecified ? "user_id" : "screen_name"
);
const Int32 MaxUsersPerCall = 100;
const Int32 MaxUrlLength = 2000;
// Construct the URL for this call.
while (
iUsersProcessed < iUsers
&&
iUsersProcessedThisCall < MaxUsersPerCall
&&
oUrl.Length < MaxUrlLength
)
{
if (iUsersProcessedThisCall > 0)
{
// Append an encoded comma. Using an unencoded comma
// causes Twitter to return a 401 "unauthorized" error.
//
// See this post for an explanation:
//
// https://dev.twitter.com/discussions/11399
oUrl.Append("%2C");
}
oUrl.Append(userIDsOrScreenNames[iUsersProcessed]);
iUsersProcessed++;
iUsersProcessedThisCall++;
}
iCalls++;
if (iCalls > 1)
{
HttpSocialNetworkUtil.ReportProgress(reportProgressHandler,
"Getting page {0}."
,
iCalls
);
}
foreach (Object oResult in EnumerateJsonValues(oUrl.ToString(),
null, Int32.MaxValue, true, requestStatistics,
reportProgressHandler, checkCancellationPendingHandler))
{
yield return((Dictionary <String, Object>)oResult);
}
}
}
EnumerateXmlNodes
(
String sUrl,
String sXPath,
Int32 iMaximumXmlNodes,
Boolean bSkipMostPage1Errors,
RequestStatistics oRequestStatistics
)
{
Debug.Assert(!String.IsNullOrEmpty(sUrl));
Debug.Assert(!String.IsNullOrEmpty(sXPath));
Debug.Assert(iMaximumXmlNodes > 0);
Debug.Assert(oRequestStatistics != null);
AssertValid();
// A maximum per-page value of 500 works for
// flickr.contacts.getPublicList (maximum per_page = 1000) and
// flickr.people.getPublicPhotos (maximum per_page = 500).
Debug.Assert(sUrl.IndexOf("flickr.contacts.getPublicList") >= 0 ||
sUrl.IndexOf("flickr.people.getPublicPhotos") >= 0);
Int32 iMaximumPerPage = Math.Min(500, iMaximumXmlNodes);
Int32 iPage = 1;
Int32 iXmlNodesEnumerated = 0;
while (true)
{
String sUrlWithPagination = String.Format(
"{0}{1}per_page={2}&page={3}"
,
sUrl,
sUrl.IndexOf('?') == -1 ? '?' : '&',
iMaximumPerPage,
iPage
);
XmlDocument oXmlDocument;
try
{
oXmlDocument = GetXmlDocument(sUrlWithPagination,
oRequestStatistics);
}
catch (Exception oException)
{
if (!HttpSocialNetworkUtil.ExceptionIsWebOrXml(oException))
{
throw oException;
}
if (iPage > 1 || bSkipMostPage1Errors)
{
// Always skip errors on page 2 and above.
yield break;
}
throw (oException);
}
XmlNodeList oXmlNodesThisPage = oXmlDocument.SelectNodes(sXPath,
null);
Int32 iXmlNodesThisPage = oXmlNodesThisPage.Count;
if (iXmlNodesThisPage == 0)
{
yield break;
}
for (Int32 i = 0; i < iXmlNodesThisPage; i++)
{
yield return(oXmlNodesThisPage[i]);
iXmlNodesEnumerated++;
if (iXmlNodesEnumerated == iMaximumXmlNodes)
{
yield break;
}
}
iPage++;
// Get the next page...
}
}