/// <summary>
/// This will delete an item from the database
/// </summary>
/// <param name="keys">The keys must be given in the same order as entity framework has them</param>
/// <returns></returns>
public async Task <ISuccessOrErrors> DeleteAsync <TEntity>(params object[] keys) where TEntity : class
{
var keyProperties = _db.GetKeyProperties <TEntity>();
if (keyProperties.Count != keys.Length)
{
throw new ArgumentException("The number of keys in the data entry did not match the number of keys provided");
}
var entityToDelete = await _db.Set <TEntity>().FindAsync(keys);
if (entityToDelete == null)
{
return
(new SuccessOrErrors().AddSingleError(
"Could not delete entry as it was not in the database. Could it have been deleted by someone else?"));
}
_db.Set <TEntity>().Remove(entityToDelete);
var result = await _db.SaveChangesWithCheckingAsync();
if (result.IsValid)
{
result.SetSuccessMessage("Successfully deleted {0}.", typeof(TEntity).Name);
}
return(result);
}
//---------------------------------------------------------------
//protected methods
/// <summary>
/// This gets the key values from this DTO in the correct order. Used in FindItemTrackedForUpdate sync/async
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
protected object[] GetKeyValues(IGenericServicesDbContext context)
{
var efkeyProperties = context.GetKeyProperties <TEntity>().ToArray();
var dtoProperties = typeof(TDto).GetProperties(BindingFlags.Public | BindingFlags.Instance);
var keysInOrder = efkeyProperties.Select(x => dtoProperties.SingleOrDefault(y => y.Name == x.Name && y.PropertyType == x.PropertyType)).ToArray();
if (keysInOrder.Any(x => x == null))
{
throw new MissingPrimaryKeyException("The dto must contain all the key(s) properties from the data class.");
}
return(keysInOrder.Select(x => x.GetValue(this)).ToArray());
}
//---------------------------------------------------------------
//protected methods
/// <summary>
/// This gets the key values from this DTO. Used in FindItemTrackedForUpdate sync/async
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
protected object[] GetKeyValues(IGenericServicesDbContext context)
{
var efkeyPropertyNames = context.GetKeyProperties <TEntity>().ToArray();
var dtoKeyProperies = typeof(TDto).GetProperties(BindingFlags.Public | BindingFlags.Instance)
.Where(x => efkeyPropertyNames.Any(y => y.Name == x.Name && y.PropertyType == x.PropertyType)).ToArray();
if (efkeyPropertyNames.Length != dtoKeyProperies.Length)
{
throw new MissingPrimaryKeyException("The dto must contain the key(s) properties from the data class.");
}
return(dtoKeyProperies.Select(x => x.GetValue(this)).ToArray());
}
//----------------------------------------------------------------------
//non-overridable internal methods
/// <summary>
/// This copies back the keys from a newly created entity into the dto as long as there are matching properties in the Dto
/// </summary>
/// <param name="context"></param>
/// <param name="newEntity"></param>
internal protected void AfterCreateCopyBackKeysToDtoIfPresent(IGenericServicesDbContext context, TEntity newEntity)
{
var dtoKeyProperies = typeof(TDto).GetProperties(BindingFlags.Public | BindingFlags.Instance);
foreach (var entityKeys in context.GetKeyProperties <TEntity>())
{
var dtoMatchingProperty =
dtoKeyProperies.SingleOrDefault(
x => x.Name == entityKeys.Name && x.PropertyType == entityKeys.PropertyType);
if (dtoMatchingProperty == null)
{
continue;
}
dtoMatchingProperty.SetValue(this, entityKeys.GetValue(newEntity));
}
}
