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);
}
}
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...
}
}
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...
}
}