private ObjectVisitationHelper(ObjectVisitationHelper other)
{
_objectSet = other._objectSet.ToDictionary(
x => x.Key,
y => y.Value,
other._objectSet.Comparer);
}
private ObjectVisitationHelper(ObjectVisitationHelper other)
{
_objectSet = other._objectSet.ToDictionary(
x => x.Key,
y => y.Value,
other._objectSet.Comparer);
}
/// <summary>
/// Helper method which initializes the given reference to ObjectVisitationHelper
/// if it is null.
/// </summary>
/// <param name="visitationHelper">Reference to ObjectVisitationHelper</param>
public static void EnsureCreated(ref ObjectVisitationHelper visitationHelper)
{
if (visitationHelper == null)
{
visitationHelper = new ObjectVisitationHelper();
}
}
// Recursively get modified properties
public static IEnumerable<IEnumerable<string>> GetModifiedProperties
(this ITrackable item, ObjectVisitationHelper visitationHelper = null)
{
// Prevent endless recursion
ObjectVisitationHelper.EnsureCreated(ref visitationHelper);
if (!visitationHelper.TryVisit(item)) yield break;
foreach (var navProp in item.GetNavigationProperties())
{
foreach (var refProp in navProp.AsReferenceProperty())
{
foreach (var modifiedProps in refProp.EntityReference.GetModifiedProperties(visitationHelper))
{
yield return modifiedProps;
}
}
foreach (var colProp in navProp.AsCollectionProperty())
{
foreach (ITrackable child in colProp.EntityCollection)
{
foreach (var modifiedProps in child.GetModifiedProperties(visitationHelper))
{
yield return modifiedProps;
}
}
}
}
yield return item.ModifiedProperties;
}
// Recursively get tracking states
public static IEnumerable<TrackingState> GetTrackingStates
(this ITrackable item, TrackingState? trackingState = null,
ObjectVisitationHelper visitationHelper = null)
{
// Prevent endless recursion
ObjectVisitationHelper.EnsureCreated(ref visitationHelper);
if (!visitationHelper.TryVisit(item)) yield break;
foreach (var navProp in item.GetNavigationProperties())
{
foreach (var refProp in navProp.AsReferenceProperty())
{
foreach (var state in refProp.EntityReference.GetTrackingStates(visitationHelper: visitationHelper))
{
if (trackingState == null || state == trackingState)
yield return state;
}
}
foreach (var colProp in navProp.AsCollectionProperty())
{
foreach (ITrackable child in colProp.EntityCollection)
{
foreach (var state in child.GetTrackingStates(visitationHelper: visitationHelper))
{
if (trackingState == null || state == trackingState)
yield return state;
}
}
}
}
yield return item.TrackingState;
}
// Recursively set tracking state
public static void SetTrackingState(this ITrackable item,
TrackingState state, ObjectVisitationHelper visitationHelper = null)
{
// Prevent endless recursion
ObjectVisitationHelper.EnsureCreated(ref visitationHelper);
if (!visitationHelper.TryVisit(item)) return;
foreach (var navProp in item.GetNavigationProperties())
{
foreach (var refProp in navProp.AsReferenceProperty())
{
refProp.EntityReference.SetTrackingState(state, visitationHelper);
refProp.EntityReference.TrackingState = state;
}
foreach (var colProp in navProp.AsCollectionProperty())
{
foreach (ITrackable child in colProp.EntityCollection)
{
child.SetTrackingState(state, visitationHelper);
child.TrackingState = state;
}
}
}
}
private static void AcceptChanges(this ITrackable item, ObjectVisitationHelper visitationHelper)
{
ObjectVisitationHelper.EnsureCreated(ref visitationHelper);
// Prevent endless recursion
if (visitationHelper != null && !visitationHelper.TryVisit(item))
{
return;
}
// Set tracking state for child collections
foreach (var navProp in item.GetNavigationProperties())
{
// Apply changes to 1-1 and M-1 properties
foreach (var refProp in navProp.AsReferenceProperty())
{
refProp.EntityReference.AcceptChanges(visitationHelper);
}
// Apply changes to 1-M properties
foreach (var colProp in navProp.AsCollectionProperty <IList>())
{
var items = colProp.EntityCollection;
var count = items.Count;
for (int i = count - 1; i > -1; i--)
{
// Stop recursion if trackable hasn't been visited
var trackable = items[i] as ITrackable;
if (trackable != null)
{
if (trackable.TrackingState == TrackingState.Deleted)
{
// Remove items marked as deleted
items.RemoveAt(i);
}
else
{
// Recursively accept changes on trackable
trackable.AcceptChanges(visitationHelper);
}
}
}
}
}
// Set tracking state and clear modified properties
item.TrackingState = TrackingState.Unchanged;
item.ModifiedProperties = null;
}
// Recursively get entity states
public static IEnumerable<EntityState> GetEntityStates(this DbContext context,
ITrackable item, EntityState? entityState = null,
ObjectVisitationHelper visitationHelper = null)
{
// Prevent endless recursion
ObjectVisitationHelper.EnsureCreated(ref visitationHelper);
if (!visitationHelper.TryVisit(item)) yield break;
foreach (var colProp in item.GetNavigationProperties().OfCollectionType())
{
foreach (ITrackable child in colProp.EntityCollection)
{
foreach (var state in context.GetEntityStates(child, visitationHelper: visitationHelper))
{
if (entityState == null || state == entityState)
yield return state;
}
}
}
yield return context.Entry(item).State;
}
/// <summary>
/// Helper method which initializes the given reference to ObjectVisitationHelper
/// if it is null.
/// </summary>
/// <param name="visitationHelper">Reference to ObjectVisitationHelper</param>
public static void EnsureCreated(ref ObjectVisitationHelper visitationHelper)
{
if (visitationHelper == null)
visitationHelper = new ObjectVisitationHelper();
}