private static async Task PrepareEntry <TEntity>(
SubmitContext context, DbContext dbContext, DataModificationEntry entry, DbSet <TEntity> set, CancellationToken cancellationToken)
where TEntity : class
{
Type entityType = typeof(TEntity);
TEntity entity;
if (entry.IsNew)
{
// TODO: See if Create method is in DbSet<> in future EF7 releases, as the one EF6 has.
entity = (TEntity)Activator.CreateInstance(typeof(TEntity));
ChangeSetPreparer.SetValues(entity, entityType, entry.LocalValues);
set.Add(entity);
}
else if (entry.IsDelete)
{
entity = (TEntity)await ChangeSetPreparer.FindEntity(context, entry, cancellationToken);
set.Remove(entity);
}
else if (entry.IsUpdate)
{
entity = (TEntity)await ChangeSetPreparer.FindEntity(context, entry, cancellationToken);
var dbEntry = dbContext.Update(entity);
ChangeSetPreparer.SetValues(dbEntry, entry, entityType);
}
else
{
throw new NotSupportedException(Resources.DataModificationMustBeCUD);
}
entry.Entity = entity;
}
private static object CreateFullUpdateInstance(DataModificationEntry entry, Type entityType)
{
// The algorithm for a "FullReplaceUpdate" is taken from ObjectContextServiceProvider.ResetResource
// in WCF DS, and works as follows:
// - Create a new, blank instance of the entity.
// - Copy over the key values and set any updated values from the client on the new instance.
// - Then apply all the properties of the new instance to the instance to be updated.
// This will set any unspecified properties to their default value.
object newInstance = Activator.CreateInstance(entityType);
ChangeSetPreparer.SetValues(newInstance, entityType, entry.EntityKey);
ChangeSetPreparer.SetValues(newInstance, entityType, entry.LocalValues);
return(newInstance);
}
static ChangeSetPreparer()
{
Instance = new ChangeSetPreparer();
}
static ChangeSetPreparer()
{
Instance = new ChangeSetPreparer();
}
private static void SetValues(EntityEntry dbEntry, DataModificationEntry entry, Type entityType)
{
//StateEntry stateEntry = ((IAccessor<InternalEntityEntry>) dbEntry.StateEntry;
IEntityType edmType = dbEntry.Metadata;
if (entry.IsFullReplaceUpdate)
{
// The algorithm for a "FullReplaceUpdate" is taken from WCF DS ObjectContextServiceProvider.ResetResource, and is as follows:
// Create a new, blank instance of the entity. Copy over the key values, and set any updated values from the client on the new instance.
// Then apply all the properties of the new instance to the instance to be updated. This will set any unspecified
// properties to their default value.
object newInstance = Activator.CreateInstance(entityType);
ChangeSetPreparer.SetValues(newInstance, entityType, entry.EntityKey);
ChangeSetPreparer.SetValues(newInstance, entityType, entry.LocalValues);
foreach (var property in edmType.GetProperties())
{
object val;
if (!entry.LocalValues.TryGetValue(property.Name, out val))
{
PropertyInfo propertyInfo = entityType.GetProperty(property.Name);
val = propertyInfo.GetValue(newInstance);
}
//stateEntry[property] = val;
dbEntry.Property(property.Name).CurrentValue = val;
}
}
else
{
// For some properties like DateTimeOffset, the backing EF property could be of a different type like DateTime, so we can't just
// copy every property pair in DataModificationEntry to EF StateEntry, instead we let the entity type to do the conversion, by
// first setting the EDM property (in DataModificationEntry) to a entity instance, then getting the EF mapped property from the
// entity instance and set to StateEntry.
object instance = null;
foreach (var property in edmType.GetProperties())
{
object val;
var edmPropName = (string)property["EdmPropertyName"];
if (edmPropName != null && entry.LocalValues.TryGetValue(edmPropName, out val))
{
if (instance == null)
{
instance = Activator.CreateInstance(entityType);
}
PropertyInfo edmPropInfo = entityType.GetProperty(edmPropName);
edmPropInfo.SetValue(instance, val);
PropertyInfo propertyInfo = entityType.GetProperty(property.Name);
val = propertyInfo.GetValue(instance);
}
else if (!entry.LocalValues.TryGetValue(property.Name, out val))
{
continue;
}
//stateEntry[property] = val;
dbEntry.Property(property.Name).CurrentValue = val;
}
}
}
