/// <summary>
/// Initializes the syndication extension context optional elements using the supplied <see cref="XPathNavigator"/>.
/// </summary>
/// <param name="source">The <b>XPathNavigator</b> used to load this <see cref="DublinCoreElementSetSyndicationExtensionContext"/>.</param>
/// <param name="manager">The <see cref="XmlNamespaceManager"/> object used to resolve prefixed syndication extension elements and attributes.</param>
/// <returns><b>true</b> if the <see cref="DublinCoreElementSetSyndicationExtensionContext"/> was able to be initialized using the supplied <paramref name="source"/>; otherwise <b>false</b>.</returns>
/// <exception cref="ArgumentNullException">The <paramref name="source"/> is a null reference (Nothing in Visual Basic).</exception>
/// <exception cref="ArgumentNullException">The <paramref name="manager"/> is a null reference (Nothing in Visual Basic).</exception>
private bool LoadOptionals(XPathNavigator source, XmlNamespaceManager manager)
{
//------------------------------------------------------------
// Local members
//------------------------------------------------------------
bool wasLoaded = false;
//------------------------------------------------------------
// Validate parameter
//------------------------------------------------------------
Guard.ArgumentNotNull(source, "source");
Guard.ArgumentNotNull(manager, "manager");
//------------------------------------------------------------
// Attempt to extract syndication extension information
//------------------------------------------------------------
XPathNavigator coverageNavigator = source.SelectSingleNode("dc:coverage", manager);
XPathNavigator formatNavigator = source.SelectSingleNode("dc:format", manager);
XPathNavigator identifierNavigator = source.SelectSingleNode("dc:identifier", manager);
XPathNavigator relationNavigator = source.SelectSingleNode("dc:relation", manager);
XPathNavigator sourceNavigator = source.SelectSingleNode("dc:source", manager);
XPathNavigator subjectNavigator = source.SelectSingleNode("dc:subject", manager);
XPathNavigator typeNavigator = source.SelectSingleNode("dc:type", manager);
if (coverageNavigator != null && !String.IsNullOrEmpty(coverageNavigator.Value))
{
this.Coverage = coverageNavigator.Value;
wasLoaded = true;
}
if (formatNavigator != null && !String.IsNullOrEmpty(formatNavigator.Value))
{
this.Format = formatNavigator.Value;
wasLoaded = true;
}
if (identifierNavigator != null && !String.IsNullOrEmpty(identifierNavigator.Value))
{
this.Identifier = identifierNavigator.Value;
wasLoaded = true;
}
if (relationNavigator != null && !String.IsNullOrEmpty(relationNavigator.Value))
{
this.Relation = relationNavigator.Value;
wasLoaded = true;
}
if (sourceNavigator != null && !String.IsNullOrEmpty(sourceNavigator.Value))
{
this.Source = sourceNavigator.Value;
wasLoaded = true;
}
if (subjectNavigator != null && !String.IsNullOrEmpty(subjectNavigator.Value))
{
this.Subject = subjectNavigator.Value;
wasLoaded = true;
}
if (typeNavigator != null && !String.IsNullOrEmpty(typeNavigator.Value))
{
DublinCoreTypeVocabularies typeVocabulary = DublinCoreElementSetSyndicationExtension.TypeVocabularyByName(typeNavigator.Value);
if (typeVocabulary != DublinCoreTypeVocabularies.None)
{
this.TypeVocabulary = typeVocabulary;
wasLoaded = true;
}
}
return(wasLoaded);
}