Module is.codion.framework.model
Package is.codion.framework.model

Interface EntityMerge

public interface EntityMerge

Merges two versions of an entity, each changed since a common base: mine, the version being edited, and theirs, the row as changed by someone else, for example the one an update failed on with an EntityModifiedException.

Lists the attributes whose values differ between the two, each with the side its value is taken from. A side is pre-selected where the base tells which version changed the value, see EntityMerge.Change. The result, merged(), is theirs with the values chosen from mine, updatable over theirs.

The attributes compared by default are the updatable columns, apart from the primary key and the columns of foreign keys, and the foreign keys whose columns are all updatable. An attribute mine does not have is not compared, and one mine has, theirs must have as well, a lazy column included, see EntityMerge.Builder.build(). A foreign key is compared by its columns, its value being the referenced entity, as loaded.

See Also:

  • Method Details

    • mine

      Entity mine()
      Returns:
      mine, the version being edited, an immutable copy

    • theirs

      Entity theirs()
      Returns:
      theirs, the row as changed by someone else, an immutable copy

    • base

      Optional<Entity> base()
      Returns:
      the base, the version both changed, an immutable copy, an empty Optional in case none was given

    • attributes

      List<EntityMerge.AttributeMerge<?>> attributes()
      Returns:
      the attributes whose values differ between mine and theirs, in the order compared

    • complete

      ObservableState complete()
      Returns:
      a state active while each attribute has a side

    • merged

      Entity merged()
      Returns theirs with the values of the attributes for which mine is chosen, theirs' values being its original ones, so that it is modified where a chosen value of mine differs, and updatable over theirs. Unmodified in case mine is chosen for no attribute.
      Returns:
      a new mutable entity, the merge result
      Throws:
      IllegalStateException - in case an attribute has no side
      See Also:

    • builder

      static EntityMerge.Builder.MineStep builder()
      Returns:
      a new EntityMerge.Builder.MineStep