/// <summary>
/// Traverse an object graph executing a callback on each node.
/// Depends on Entity Framework Core infrastructure, which may change in future releases.
/// </summary>
/// <param name="context">Used to query and save changes to a database</param>
/// <param name="item">Object that implements ITrackable</param>
/// <param name="callback">Callback executed on each node in the object graph</param>
public static void TraverseGraph(this DbContext context, object item,
Action <EntityEntryGraphNode> callback)
{
IStateManager stateManager = context.Entry(item).GetInfrastructure().StateManager;
var node = new EntityEntryGraphNode(stateManager.GetOrCreateEntry(item), null, null);
IEntityEntryGraphIterator graphIterator = new EntityEntryGraphIterator();
var visited = new HashSet <int>();
graphIterator.TraverseGraph(node, n =>
{
// Check visited
if (visited.Contains(n.Entry.Entity.GetHashCode()))
{
return(false);
}
// Execute callback
callback(n);
// Add visited
visited.Add(n.Entry.Entity.GetHashCode());
// Return true if node state is null
return(true);
});
}
/// <summary>
/// Traverse an object graph executing a callback on each node.
/// </summary>
/// <param name="context">Used to query and save changes to a database</param>
/// <param name="item">Object that implements ITrackable</param>
/// <param name="callback">Callback executed on each node in the object graph</param>
public static void TraverseGraph(this DbContext context, object item,
Action <EntityEntryGraphNode> callback)
{
#pragma warning disable EF1001 // Internal EF Core API usage.
IStateManager stateManager = context.Entry(item).GetInfrastructure().StateManager;
var node = new EntityEntryGraphNode <object>(stateManager.GetOrCreateEntry(item), null, null, null);
IEntityEntryGraphIterator graphIterator = new EntityEntryGraphIterator();
#pragma warning restore EF1001 // Internal EF Core API usage.
var visited = new HashSet <object>();
graphIterator.TraverseGraph(node, n =>
{
// Check visited
if (visited.Contains(n.Entry.Entity))
{
return(false);
}
// Execute callback
callback(n);
// Add visited
visited.Add(n.Entry.Entity);
// Continue traversal
return(true);
});
}
/// <summary>
/// Traverse an entity graph executing a callback on each node.
/// </summary>
/// <param name="context">The entity graph context.</param>
/// <param name="entity">The entity to start traversing the graph from.</param>
/// <param name="callback">The callback executed on each node in the entity graph.</param>
public static void TraverseGraph(this DbContext context, object entity, Action <EntityEntryGraphNode> callback)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (callback == null)
{
throw new ArgumentNullException(nameof(callback));
}
#pragma warning disable EF1001 // Internal EF Core API usage.
var graph = new EntityEntryGraphIterator( );
var visited = new HashSet <object> ( );
var entry = context.Entry(entity).GetInfrastructure( );
var root = new EntityEntryGraphNode <object?> (entry, null, null, null);
graph.TraverseGraph(root, node =>
{
if (!visited.Add(node.Entry.Entity))
{
return(false);
}
callback(node);
return(true);
});
#pragma warning restore EF1001 // Internal EF Core API usage.
}