public XElement GetElement(RhspDataID dataID, Type dataType)
{
RhspDataAttribute hda = GetRuntimeHda(dataType);
XElement element = getElementUsingHda(ConfigDocument, dataID, hda);
return(element);
}
public bool Exists(RhspDataID dataID, Type type)
{
RhspDataAttribute hda = GetRuntimeHda(type);
XElement parent = getParent(ConfigDocument, hda.Parent);
return(find(parent, dataID, hda).Count() != 0);
}
private object createFromElement(XElement element, Type dataType)
{
try
{
RhspDataAttribute hda = GetRuntimeHda(dataType);
object data = Activator.CreateInstance(dataType);
if (data is IRhspData)
{
IRhspData hd = (IRhspData)data;
hd.DataID = new RhspDataID(element.Element(hda.ID).Value);
hd.FromElement(element, this);
}
else
{
throw new NotSupportedException(
"The data type must implement interface " +
typeof(IRhspData).Name + " for an instance " +
"to be created from an XML element.");
}
return(data);
}
catch (TargetInvocationException ex)
{
// Rethrow the target invocation exception, but pull the message to the top.
throw new TargetInvocationException(ex.InnerException.Message, ex.InnerException);
}
}
private void deleteWithoutSave(RhspDataID dataID, Type dataType, XDocument document)
{
RhspDataAttribute hdca = GetRuntimeHda(dataType);
XElement element = getElementUsingHda(document, dataID, hdca);
// Simply remove the element.
element.Remove();
}
public IEnumerable <TData> GetQueryForAllOfType <TData>()
where TData : IRhspData
{
RhspDataAttribute hdca = GetRuntimeHda(typeof(TData));
XElement parent = getParent(ConfigDocument, hdca.Parent);
return(from element in parent.Elements()
select(TData) createFromElement(element, typeof(TData)));
}
private void update(IRhspData data, XDocument document)
{
RhspDataAttribute hdca = GetRuntimeHda(data.GetType());
XElement element = getElementUsingHda(document, data.DataID, hdca);
// Delegate element update to object it's self.
data.UpdateElement(element, this);
/* Set the latest schema version (as re-saving automatically
* updates the object to this version). Versions are only ever
* opened as earlier versions and never saved as this. */
updateVersionElement(element, hdca);
}
private void updateVersionElement(XElement element, RhspDataAttribute hdca)
{
var q = from e in element.Elements()
where e.Name == SchemaVersionElement
select e;
/* Due to a bug in earlier versions, there may be multiple version tags,
* so remove any version tags that exist already. */
q.Remove();
if (hdca.SchemaVersion != 0)
{
// Re-add the element after removing any traces (only if version specified).
element.AddFirst(new XElement(SchemaVersionElement, hdca.SchemaVersion));
}
}
private XElement getElementUsingHda(
XDocument document,
RhspDataID dataID,
RhspDataAttribute hda)
{
XElement parent = getParent(document, hda.Parent);
var uniqueQuery = find(parent, dataID, hda);
// Ensure that ID actually exists.
if (uniqueQuery.Count() == 0)
{
throw new InvalidOperationException(
"Unable to find element with unique ID of '" + dataID.Value + "'.");
}
return(uniqueQuery.First());
}
private IEnumerable <XElement> find(
XElement parent,
RhspDataID dataID,
RhspDataAttribute hda)
{
if (dataID == null)
{
throw new ArgumentNullException("dataID");
}
return(from child in
(
from element in parent.Elements()
select element.Element(hda.ID)
)
where child.Value == dataID.Value
select child.Parent); // Select the owner of the ID.
}
private void create(IRhspData data, XDocument document)
{
if (data.DataID == null)
{
throw new Exception(
"Hosting ID cannot be unassigned.");
}
RhspDataAttribute hda = GetRuntimeHda(data.GetType());
XElement parent = getParent(document, hda.Parent);
var uniqueQuery = find(parent, data.DataID, hda);
// Ensure that IDs are not duplicated.
if (uniqueQuery.Count() != 0)
{
throw new InvalidOperationException(
"An element with name '" + hda.Name + "' in parent " +
"'" + hda.Parent + "' already contains unique ID " +
"with value of '" + data.DataID + "'.");
}
// Get original data without unique ID present.
XElement element = data.ToXElement(this);
// Add ID first for better visual diagnosis.
element.AddFirst(new XElement(hda.ID, data.DataID.Value));
if (hda.SchemaVersion != 0)
{
// Add version before the ID element, but only if neccecary.
element.AddFirst(new XElement(SchemaVersionElement, hda.SchemaVersion));
}
// Add the element with unique ID present.
parent.Add(element);
}
