/// <summary>
/// Calculate count of principal self navigation properties for
/// ordering to be able to successfully define order.
/// </summary>
/// <remarks>
/// If Category has principal navigation to itself named ParentCategory, we need to
/// find count of them to be able to define order appropriately. We need to define state of
/// them in ascending order.
/// </remarks>
/// <example>
/// firstCategory which has null value on ParentCategory property has 0 principal self
/// navigation count. If ParentCategory of secondCategory is firstCategory, then secondCategory
/// has 1 principal self navigation count, if ParentCategory of thirdCateogry is secondCategory,
/// then it has 2 principal self navigaiton count.
/// </example>
/// <typeparam name="TEntity">Type of entity.</typeparam>
/// <param name="entity">Entity to find principla self navigaiton count.</param>
/// <param name="store">Store to add calculated count and check first.</param>
/// <returns>Count of principal self navigation count.</returns>
private int CalculatePrincipalSelfNavigationCount <TEntity>(
TEntity entity,
Dictionary <object, int> store)
where TEntity : class
{
if (store.ContainsKey(entity))
{
return(store[entity]);
}
string typeName = entity.GetType().Name;
// Get navigation details and find properties which is refers to itslef.
IGraphEntityManager <TEntity> entityManager = GetEntityManager <TEntity>();
NavigationDetail navigationDetail = entityManager.GetNavigationDetail();
List <string> selfReferringPrincipalPropertyNames = navigationDetail
.Relations
.Where(m => m.Direction == NavigationDirection.From &&
m.PropertyTypeName == typeName)
.Select(m => m.PropertyName)
.ToList();
// Loop through principal navigation properties and add their count.
int principalSelfCount = 0;
foreach (string propertyName in selfReferringPrincipalPropertyNames)
{
TEntity principalEntity = entity.GetPropertyValue(propertyName) as TEntity;
// If principla entity is null then continue
if (principalEntity == null)
{
continue;
}
// Othewise calculate principal count as 1 + count for principal entity
principalSelfCount++;
principalSelfCount += CalculatePrincipalSelfNavigationCount(principalEntity, store);
}
store.Add(entity, principalSelfCount);
return(principalSelfCount);
}
/// <summary>
/// Add all child or parents entities related to given entity
/// and entity itself to the relatedEntityList.
/// </summary>
/// <exception cref="ArgumentNullException">
/// When entity or relatedEntityList is null.
/// </exception>
/// <typeparam name="TEntity">Type of entity.</typeparam>
/// <param name="entity">Entity to get all related entities.</param>
/// <param name="relatedEntityList">List of entities to add.</param>
public void GetAllEntities <TEntity>(
TEntity entity,
List <object> relatedEntityList)
where TEntity : class
{
if (entity == null)
{
throw new ArgumentNullException(nameof(entity));
}
if (relatedEntityList == null)
{
throw new ArgumentNullException(nameof(relatedEntityList));
}
if (!relatedEntityList.Contains(entity))
{
relatedEntityList.Add(entity);
}
IGraphEntityManager <TEntity> graphEntityManager = GetEntityManager <TEntity>();
NavigationDetail navigationDetail = graphEntityManager
.GetNavigationDetail();
List <PropertyInfo> navigationPropeties = navigationDetail
.Relations
.Select(n => entity.GetProperty(n.PropertyName))
.ToList();
if (navigationPropeties != null &&
navigationPropeties.Count > 0)
{
foreach (PropertyInfo childEntityProperty in navigationPropeties)
{
if (childEntityProperty.PropertyType.IsCollectionType())
{
// If child entity is collection get all entities inside this collection.
IEnumerable <object> enumerableChildEntity =
entity.GetPropertyValue(childEntityProperty.Name) as IEnumerable <object>;
if (enumerableChildEntity != null)
{
for (int i = 0; i < enumerableChildEntity.Count(); i++)
{
dynamic childEntity = enumerableChildEntity.ElementAt(i);
if (childEntity != null &&
!relatedEntityList.Contains(childEntity))
{
GetAllEntities(
childEntity,
relatedEntityList);
}
}
}
}
else
{
// If child entity is not collection get its own.
dynamic childEntity = entity.GetPropertyValue(childEntityProperty.Name);
if (childEntity != null &&
!relatedEntityList.Contains(childEntity))
{
GetAllEntities(
childEntity,
relatedEntityList);
}
}
}
}
}
/// <summary>
/// Set property of parent entity to targetValue
/// which has property value equals to currentValue.
/// </summary>
/// <typeparam name="TEntity">Type of entity.</typeparam>
/// <param name="currentValue">Current value of property to replace.</param>
/// <param name="targetValue">Target value to set value of property of parent.</param>
private void ReplaceEntitiesInParents <TEntity>(
TEntity currentValue,
TEntity targetValue)
where TEntity : class
{
IGraphEntityManager <TEntity> graphEntityManager = GetEntityManager <TEntity>();
NavigationDetail navigationDetailOfCurrent = graphEntityManager
.GetNavigationDetail();
// Get parent properties of entity.
// Properties which have navigation property type of which
// is type of entity. Ignore navigation properties
// which are mutual navigation properties with entity itself.
string typeName = currentValue.GetType().Name;
List <NavigationDetail> parentNavigationDetails = GetNavigationDetails()
.Select(n => new NavigationDetail()
{
SourceTypeName = n.SourceTypeName,
Relations = n.Relations
.Where(r => r.PropertyTypeName.Equals(typeName) &&
r.SourceMultiplicity == RelationshipMultiplicity.Many &&
!navigationDetailOfCurrent
.Relations
.Any(c => c.PropertyTypeName.Equals(n.SourceTypeName) &&
c.TargetMultiplicity == r.SourceMultiplicity &&
c.FromKeyNames.SequenceEqual(r.FromKeyNames) &&
c.ToKeyNames.SequenceEqual(r.ToKeyNames)))
.ToList()
})
.Where(n => n.Relations != null &&
n.Relations.Count() > 0)
.ToList();
// Get assembly to be able to get types according to type name
Assembly entityAssembly = currentValue.GetType().Assembly;
if (parentNavigationDetails != null && parentNavigationDetails.Count() > 0)
{
foreach (NavigationDetail parentNavigation in parentNavigationDetails)
{
Type parentType = entityAssembly.GetTypes()
.FirstOrDefault(t => t.Name.Equals(parentNavigation.SourceTypeName));
// Get local set of parent
IEnumerable <object> localParentSet = Context
.Set(parentType)
.Local
.CastToGeneric();
foreach (NavigationRelation navigationRelation in parentNavigation.Relations)
{
PropertyInfo childProperty =
parentType.GetProperty(navigationRelation.PropertyName);
if (!childProperty.PropertyType.IsCollectionType())
{
// Get all parent entities which have current entity inside
var containerParentCollection = localParentSet
.Where(m => m.GetPropertyValue(navigationRelation.PropertyName) != null &&
m.GetPropertyValue(navigationRelation.PropertyName).Equals(currentValue))
.ToList();
// If collection is empty then skip.
if (containerParentCollection == null ||
containerParentCollection.Count == 0)
{
continue;
}
foreach (var containerParent in containerParentCollection)
{
// If parent is null then skip.
if (containerParent == null)
{
continue;
}
// If parent with property value of currentValue found replace values
/*
* If duplicate entity is in the entity, state of which has already
* been defined and if state of this parent entity is Unchanged or
* Modified, trying to change navigation property of this parent entity
* will throw InvalidOperationException with following message:
* "A referential integrity constraint violation occurred:
* A primary key property that is a part of referential integrity constraint
* cannot be changed when the dependent object is Unchanged unless it is being
* set to the association's principal object. The principal object must
* be tracked and not marked for deletion."
* As a workaround I am storing current state of parent entity, changing the
* state to Added, then replacing duplicate entity and in the end
* I set state of parent entity to stored current state.
*/
// Store current state
var currentState = Context.Entry(containerParent).State;
// Change state to added
Context.Entry(containerParent).State = EntityState.Added;
// Replace value through
// context.Entry(containerParent).Member(propertyName).CurrentValue
// because otherwise EntityFramework will not be able to track entities
Context.Entry(containerParent)
.Member(navigationRelation.PropertyName).CurrentValue = targetValue;
// Restore state to current state
Context.Entry(containerParent).State = currentState;
}
}
}
}
}
}
