The MetaMapper that provides create and findAll functionality etc.
Adds a new, unsaved item
The list of items pending to be added to the database
The sort direction
The list of items that correspond to items in the database
Returns the items (current + added - removed), sorted.
Reloads the contents of 'current' from the database
Reset the ItemsList from the database: calls refresh, and 'added' and 'removed' are cleared.
Marks an item pending for removal
The list of items to be deleted from current
Sends to the database: added is saved removed is deleted (current - removed) is saved
The field to sort by, if any
Whether the sorting algorithm should put null first or last