public static void UpdateManyToManyLinkAndEntities <T>(IEnumerable <T> disconnectedLinksEnumerable, DbContext dbContext, Type mainType, Type dependentType) where T : class
{
var linkType = typeof(T);
LinkPropsInfo mainPropsInfo = FindLinkEntityPropInfo(linkType, mainType);
LinkPropsInfo dependentPropsInfo = FindLinkEntityPropInfo(linkType, dependentType);
PropertyInfo mainListLinkPropInfo = FindListPropInMainEntity(linkType, mainType);
//Guards: make sure class has only navigational properties (that is, Movie,MovieId,Entity,EntityId)
if (mainListLinkPropInfo == null ||
mainPropsInfo.entity == null ||
mainPropsInfo.id == null ||
dependentPropsInfo.entity == null ||
dependentPropsInfo.id == null ||
linkType.GetProperties().Length != 4)
{
throw new ArgumentException("Error while trying to get types of many-to-many link entities. Could not find entity type.");
}
dynamic linkDbSet = dbContext.GetDbSetWithReflection(linkType);
dynamic mainDbSet = dbContext.GetDbSetWithReflection(mainType);
dynamic dependentDbSet = dbContext.GetDbSetWithReflection(dependentPropsInfo.entity.PropertyType);
//Por cada link desconnectado, miro si existe y si no existe, miro si existen cada uno de los componentes y los creo si son necesarios asi como el link
foreach (var link in disconnectedLinksEnumerable)
{
var mainId = (string)mainPropsInfo.id.GetValue(link);
var dependentId = (string)dependentPropsInfo.id.GetValue(link);
var existingLink = linkDbSet.Find(new object[] { mainId, dependentId });
if (existingLink != null)
{
continue;
}
UpdateEntity((Entity)dependentPropsInfo.entity.GetValue(link), dbContext);
var existingDependent = dependentDbSet.Find(new object[] { dependentId });
if (existingDependent == null)
{
throw new RepositoryException("Entity not added correctly when updating many to many link");
}
var existingMain = mainDbSet.Find(new object[] { mainId });
if (existingMain == null)
{
throw new RepositoryException("Movie not found when updating many to many link");
}
var newLink = Activator.CreateInstance(linkType);
mainPropsInfo.id.SetValue(newLink, mainId);
mainPropsInfo.entity.SetValue(newLink, existingMain);
dependentPropsInfo.id.SetValue(newLink, dependentId);
dependentPropsInfo.entity.SetValue(newLink, existingDependent);
var existingMovieLinkList = mainListLinkPropInfo.GetValue(existingMain);
mainListLinkPropInfo.PropertyType.GetMethod("Add").Invoke(existingMovieLinkList, new object[] { newLink });
}
}
private static LinkPropsInfo FindLinkEntityPropInfo(Type linkType, Type entityType)
{
LinkPropsInfo linkEntityPropsInfo = new LinkPropsInfo();
foreach (var prop in linkType.GetProperties())
{
if (prop.PropertyType == entityType)
{
linkEntityPropsInfo.entity = prop;
}
else if (prop.PropertyType != entityType && prop.Name.Contains(entityType.Name) && prop.Name.Substring(prop.Name.Length - 2).Equals("Id"))
{
linkEntityPropsInfo.id = linkType.GetProperty(prop.Name);
}
}
return(linkEntityPropsInfo);
}
