[TYPO3-mvc] Sorting of frontend created records

[roberto blanko]

Hello list,

I've got records of the same type which can be arranged in a hierarchical
structure, using child/parent-relations. In the backend children can be
added using IRRE. Also I am using manual sorting of records by having a
separated sorting column in the db (the common TYPO3 practice).

When I create new records within the hierarchy somewhere in the backend
using IRRE or the DB list module, the sorting works like expected. New
records are added to the end of the list (are getting the last sorting plus
1).

My plugin also allows to create new records in the frontend using Extbase
and Fluid. I'm  adding fields by simply creating new objects, assigning them
to their parent records and then adding them to the repository. But by doing
so, new records are always added to the top of the list. Which means Extbase
gives them sorting number 1 and increases the sorting number of all other
records on the same hierachy level by one.

Is there a nice Extbase'ish way to turn this behaviour around, so new
records are persisted to the bottom?

Thanks for any help!