private IList GetChildren(IBlueSphereEntity parent, Type childType, string childIdentifyingPropertyName, object childIdentifyingPropertyValue, Database.IConnection connection)
{
var tableMapping = connection.GetMapping(childType);
string query = string.Format("select * from {0} where {1} = ?", childType.GetTableName(),
childType.GetForeignKeyName(parent.GetType()));
if (!string.IsNullOrEmpty(childIdentifyingPropertyName))
{
query = query + string.Format(" AND {0} = ?", childIdentifyingPropertyName);
}
IList <object> queryResults;
if (!string.IsNullOrEmpty(childIdentifyingPropertyName))
{
queryResults = connection.Query(tableMapping, query, parent.ID, childIdentifyingPropertyValue);
}
else
{
queryResults = connection.Query(tableMapping, query, parent.ID);
}
// Create a typed generic list we can assign back to parent element
IList genericList = (IList)Activator.CreateInstance(typeof(List <>).MakeGenericType(childType));
foreach (object item in queryResults)
{
genericList.Add(item);
}
return(genericList);
}
/// <summary>
/// Performs some action (e.g. insert or delete) recursively on the hierarchical object graph using using the
/// ChildRelationship and ForeignKey attributes to guide the process. Deals with the cases where child properties
/// are lists or single items.
/// </summary>
/// <param name="entity"></param>
/// <param name="relationshipProperty"></param>
/// <param name="action"></param>
private void DoRecursiveTreeAction(IBlueSphereEntity entity, PropertyInfo relationshipProperty, Action <IBlueSphereEntity, IBlueSphereEntity> action)
{
if (relationshipProperty.GetCardinalityOfChildRelation() == RelationshipCardinality.OneToOne)
{
//Child Property is a single Bluesphere entity
IBlueSphereEntity singleChild = relationshipProperty.GetValue(entity, null) as IBlueSphereEntity;
if (singleChild == null)
{
throw new ArgumentException(string.Format("{0} type property {1} is not a BlueSphere entity", entity.GetType().ToString(), relationshipProperty.Name));
}
action.Invoke(entity, singleChild);
}
else if (relationshipProperty.GetCardinalityOfChildRelation() == RelationshipCardinality.OneToZeroOrOne)
{
//Child Property is a single Bluesphere entity but may be null
var singleChild = relationshipProperty.GetValue(entity, null);
if (singleChild != null)
{
var singleChildBlueSphereEntity = singleChild as IBlueSphereEntity;
if (singleChildBlueSphereEntity == null)
{
throw new ArgumentException(string.Format("{0} type property {1} is not a BlueSphere entity", entity.GetType().ToString(), relationshipProperty.Name));
}
action.Invoke(entity, singleChildBlueSphereEntity);
}
}
else
{
// Child property is a collection of Bluesphere entities
IEnumerable <IBlueSphereEntity> children = relationshipProperty.GetValue(entity, null) as IEnumerable <IBlueSphereEntity>;
if (children != null)
{
foreach (var child in children)
{
action.Invoke(entity, child);
}
}
}
}
/// <summary>
/// Deletes a potentially nested object graph from the appropriate tables using the
/// ChildRelationship and ForeignKey attributes to guide the process
/// </summary>
/// <param name="entity"></param>
private void DeleteRecursive(IBlueSphereEntity entity, Database.IConnection connection)
{
try
{
connection.Delete(entity);
}
catch (Exception ex)
{
throw new Exception(string.Format("Failed to delete from table {0}, entity ID {1}.", entity.GetType().GetTableName(), entity.ID), ex);
}
var relationshipProperties = entity.GetType().GetChildRelationProperties();
foreach (var relationshipProperty in relationshipProperties)
{
this.DoRecursiveTreeAction(entity, relationshipProperty, (parent, child) =>
{
this.DeleteRecursive(child, connection);
});
}
}
/// <summary>
/// Private non-async version of PopulateChildrenRecursiveAsync for use within a transaction
/// </summary>
private void PopulateChildrenRecursive(IBlueSphereEntity parent, Database.IConnection connection)
{
var relationshipProperties = parent.GetType().GetChildRelationProperties();
foreach (var relationshipProperty in relationshipProperties)
{
Type childType = relationshipProperty.GetTypeOfChildRelation();
string childIdentifyingPropertyName = relationshipProperty.GetIdentifyingPropertyNameOfChildRelation();
object childIdentifyingPropertyValue = relationshipProperty.GetIdentifyingPropertyValueOfChildRelation();
IList children = this.GetChildren(parent, childType, childIdentifyingPropertyName, childIdentifyingPropertyValue, connection);
if (relationshipProperty.GetCardinalityOfChildRelation() == RelationshipCardinality.OneToOne)
{
Debug.Assert(children.Count == 1, string.Format("Expected one child of type {0} for parent {1} '{2}' but found {3}", childType.Name, parent.GetType().Name, parent.ID, children.Count));
relationshipProperty.SetValue(parent, children[0]);
}
else if (relationshipProperty.GetCardinalityOfChildRelation() == RelationshipCardinality.OneToZeroOrOne)
{
Debug.Assert(children.Count <= 1, string.Format("Expected zero or one child of type {0} for parent {1} '{2}' but found {3}", childType.Name, parent.GetType().Name, parent.ID, children.Count));
if (children.Count == 1)
{
relationshipProperty.SetValue(parent, children[0]);
}
}
else
{
relationshipProperty.SetValue(parent, children);
}
foreach (var child in children)
{
this.PopulateChildrenRecursive(child as IBlueSphereEntity, connection);
}
}
}
// Ensures the property on the child labelled with the foreign key attribute lines up with
// the id of the parent
private static void SetForeignKeyOnChild(IBlueSphereEntity parent, IBlueSphereEntity child)
{
PropertyInfo foreignKeyPropInfo = child.GetType().GetForeignKeyProperty(parent.GetType());
foreignKeyPropInfo.SetValue(child, parent.ID);
}
