Is it possible to create my own projection?
Is there an example of this?
I would like to create my own (complicated) calculation based on a projection.
As an example, I looked at the class function Substring in Aurelius.Criteria.Projections. I would like to create a unit with my own calculations that I can use within Aurelius.
Is there a documentation or an example project for this?
The calculations are not based on SQL, but are performed completely stand alone (I even want to put a REST API call there).
Projections are used to be included in the SQL statement. If you don't want to use it in SQL statement, then it wouldn't make sense to use projections.
I see in code that FProjection field is private, and you will need it from the class helper. So for now you need to modify the existing source code by creating a protected read-only property to access the FProjection field. Other than this, just create the class helper and implement the methods.