private async Task <IReadOnlyList <EntityVersion <WebResourceName, string> > > GetVersions(DateTimeRange?range, string entityType)
{
var entities = new List <EntityVersion <WebResourceName, string> >();
try
{
var responseXml = await _webDavClient.ExecuteWebDavRequestAndReadResponse(
_serverUrl,
"REPORT",
1,
null,
null,
"application/xml",
string.Format(
@"<?xml version=""1.0""?>
<C:calendar-query xmlns:C=""urn:ietf:params:xml:ns:caldav"">
<D:prop xmlns:D=""DAV:"">
<D:getetag/>
</D:prop>
<C:filter>
<C:comp-filter name=""VCALENDAR"">
<C:comp-filter name=""{0}"">
{1}
</C:comp-filter>
</C:comp-filter>
</C:filter>
</C:calendar-query>
",
entityType,
range == null ? string.Empty : string.Format(@"<C:time-range start=""{0}"" end=""{1}""/>",
range.Value.From.ToString(s_calDavDateTimeFormatString),
range.Value.To.ToString(s_calDavDateTimeFormatString))
));
XmlNodeList responseNodes = responseXml.XmlDocument.SelectNodes("/D:multistatus/D:response", responseXml.XmlNamespaceManager);
// ReSharper disable once LoopCanBeConvertedToQuery
// ReSharper disable once PossibleNullReferenceException
foreach (XmlElement responseElement in responseNodes)
{
var urlNode = responseElement.SelectSingleNode("D:href", responseXml.XmlNamespaceManager);
var etagNode = responseElement.SelectSingleNode("D:propstat/D:prop/D:getetag", responseXml.XmlNamespaceManager);
if (urlNode != null &&
etagNode != null &&
_serverUrl.AbsolutePath != UriHelper.DecodeUrlString(urlNode.InnerText))
{
var uri = new WebResourceName(urlNode.InnerText);
entities.Add(EntityVersion.Create(uri, HttpUtility.GetQuotedEtag(etagNode.InnerText)));
}
}
}
catch (WebDavClientException x)
{
// Workaround for Synology NAS, which returns 404 insteaod of an empty response if no events are present
if (x.StatusCode == HttpStatusCode.NotFound && await IsResourceCalender())
{
return(entities);
}
throw;
}
return(entities);
}