UPGRADING.md

Upgrading

Upgrading to >= 2.0.0

The second argument yielded in the block in Mongoid::Criteria::Scrollable#scroll and Mongo::Scrollable#scroll has changed from a cursor to an instance of Mongoid::Criteria::Scrollable which provides next_cursor and previous_cursor. The next_cursor method returns the same cursor as in versions prior to 2.0.0.

For example, this code:

Feed::Item.asc(field_name).limit(2).scroll(cursor) do |_, next_cursor|
  cursor = next_cursor
end

Should be updated to:

Feed::Item.asc(field_name).limit(2).scroll(cursor) do |_, iterator|
  cursor = iterator.next_cursor
end

Upgrading to >= 1.0.0

Mismatched Sort Fields

Both Mongoid::Criteria::Scrollable#scroll and Mongo::Scrollable now raise a Mongoid::Scroll::Errors::MismatchedSortFieldsError when there are discrepancies between the cursor sort options and the original sort options.

For example, the following code will now raise a MismatchedSortFieldsError because we set a different field name (position) from the created_at field used to sort in scroll.

cursor.field_name = "position"
Feed::Item.desc(:created_at).scroll(cursor)