public static IReadOnlyList <T> UpdateManyToMany <T, TParent, TChild, TChildDto>(this IFolkeConnection connection, TParent parent, IReadOnlyList <T> currentValues, ICollection <TChildDto> newDtos, IManyToManyHelperConfiguration <TChild, TChildDto> helper)
where T : class, IManyToManyTable <TParent, TChild>, new()
where TParent : IFolkeTable
where TChild : class, IFolkeTable, new()
{
if (newDtos == null)
{
newDtos = new List <TChildDto>();
}
// Looking for any value in newDtos that is not in currentValues
var valuesToAdd = newDtos.Where(v => currentValues == null || !currentValues.Any(cv => helper.AreEqual(cv.Child, v))).ToList();
var newValues = currentValues?.ToList() ?? new List <T>();
if (valuesToAdd.Any())
{
// Query from the database the values that needs to be added to the parent
var existingChildren = helper.QueryExisting(connection, valuesToAdd);
foreach (var newDto in valuesToAdd)
{
var child = existingChildren?.SingleOrDefault(c => helper.AreEqual(c, newDto));
if (child == null)
{
// If the element to add does not exist in the database, create it (may fail if helper.Map/helper.UpdateDto is not implemented because one does not want to allow that)
child = helper.Map(newDto);
connection.Save(child);
helper.UpdateDto(newDto, child);
}
// Create a new parent-child link with this value
var newElement = new T {
Child = child, Parent = parent
};
connection.Save(newElement);
newValues.Add(newElement);
}
}
if (currentValues != null)
{
// Look for values to remove
var valuesToRemove = currentValues.Where(cv => newDtos.All(nv => !helper.AreEqual(cv.Child, nv))).ToArray();
if (valuesToRemove.Any())
{
connection.Delete <T>().From().Where(c => c.Id.In(valuesToRemove.Select(s => s.Id))).Execute();
foreach (var value in valuesToRemove)
{
newValues.Remove(value);
}
}
}
return(newValues);
}
public void Delete(int id)
{
Product product = session.Get <Product>(id);
if (product == null)
{
return;
}
session.Delete <Product>(product);
return;
}
/// <summary>
/// Updates a collection of items from a collection of item views. Existing items are updated or deleted. New items are added.
/// </summary>
/// <typeparam name="TChild">The database item</typeparam>
/// <typeparam name="TChildView">A view of this database item. Matching items have same Id</typeparam>
/// <param name="connection">The database connection</param>
/// <param name="currentValues">The current value from the database</param>
/// <param name="newValues">The new values</param>
/// <param name="factory">A factory that create a new item</param>
/// <param name="updater">A delegate that updates an existing item</param>
public static List <TChild> UpdateCollectionFromViews <TChild, TChildView>(this IFolkeConnection connection, IReadOnlyCollection <TChild> currentValues, IReadOnlyCollection <TChildView> newValues,
Func <TChildView, TChild> factory, Func <TChildView, TChild, bool> updater)
where TChild : class, IFolkeTable, new()
where TChildView : class, IFolkeTable, new()
{
var ret = new List <TChild>();
if (currentValues == null || !currentValues.Any())
{
foreach (var childValue in newValues)
{
var child = factory(childValue);
ret.Add(child);
connection.Save(child);
}
return(ret);
}
var newValueToAdd = newValues.Where(x => currentValues.All(y => y.Id != x.Id));
foreach (var currentValue in currentValues)
{
var newValue = newValues.FirstOrDefault(x => x.Id == currentValue.Id);
if (newValue == null)
{
connection.Delete(currentValue);
}
else
{
if (updater != null && updater(newValue, currentValue))
{
connection.Update(currentValue);
}
ret.Add(currentValue);
}
}
foreach (var childDto in newValueToAdd)
{
var child = factory(childDto);
ret.Add(child);
connection.Save(child);
}
return(ret);
}
/// <summary>
/// Update a collection of items using a collection of values. These values don't have an id to identity them, so a areEqual delegate
/// must be given as a parameter. Existing items that is not in newValues are deleted.
/// </summary>
/// <typeparam name="TChild">The database item type</typeparam>
/// <typeparam name="TChildView">The view type</typeparam>
/// <param name="connection">The database connection</param>
/// <param name="currentValues">The current value from the database</param>
/// <param name="newValues">The new values</param>
/// <param name="areEqual">Must return true if the two values are equal</param>
/// <param name="factory">Create a new item</param>
public static List <TChild> UpdateCollectionFromValues <TChild, TChildView>(this IFolkeConnection connection, IReadOnlyCollection <TChild> currentValues, IReadOnlyCollection <TChildView> newValues,
Func <TChildView, TChild> factory, Func <TChildView, TChild, bool> areEqual)
where TChild : class, IFolkeTable, new()
{
var ret = new List <TChild>();
if (currentValues == null || !currentValues.Any())
{
foreach (var childValue in newValues)
{
var child = factory(childValue);
connection.Save(child);
ret.Add(child);
}
return(ret);
}
var newValueToAdd = newValues.Where(x => currentValues.All(y => !areEqual(x, y)));
foreach (var currentValue in currentValues)
{
if (!newValues.Any(x => areEqual(x, currentValue)))
{
connection.Delete(currentValue);
}
else
{
ret.Add(currentValue);
}
}
foreach (var childDto in newValueToAdd)
{
var child = factory(childDto);
connection.Save(child);
ret.Add(child);
}
return(ret);
}
