internal static ThingBase DeserializeItem(XPathNavigator thingNav)
{
ThingBase result;
Guid typeId = GetTypeId(thingNav);
ThingTypeHandler handler = null;
if (typeId == s_applicationSpecificId)
{
// Handle application specific health item records by checking for handlers
// for the application ID and subtype tag. If the handler doesn't exist
// the default handler will be picked up below.
AppDataKey appDataKey = GetAppDataKey(thingNav);
if (appDataKey != null)
{
if (s_appSpecificHandlers.ContainsKey(appDataKey.AppId))
{
if (s_appSpecificHandlers[appDataKey.AppId].ContainsKey(appDataKey.SubtypeTag))
{
handler =
s_appSpecificHandlers[appDataKey.AppId][appDataKey.SubtypeTag];
}
}
}
}
if (handler == null &&
TypeHandlers.ContainsKey(typeId))
{
handler = TypeHandlers[typeId];
}
if (handler != null)
{
result = (ThingBase)Activator.CreateInstance(handler.ItemTypeClass);
}
else
{
result = new ThingBase(typeId);
}
result.ParseXml(thingNav, thingNav.OuterXml);
return(result);
}
private static AppDataKey GetAppDataKey(XPathNavigator thingNav)
{
AppDataKey result = null;
XPathNavigator appIdNav =
thingNav.SelectSingleNode("data-xml/app-specific/format-appid");
XPathNavigator subtypeNav =
thingNav.SelectSingleNode("data-xml/app-specific/format-tag");
if (appIdNav != null && subtypeNav != null)
{
result = new AppDataKey
{
AppId = appIdNav.Value,
SubtypeTag = subtypeNav.Value
};
}
return(result);
}