An example of cases in which this may make different code results when inserting and then recalculating
The addition row has not yet been recorded in the database — therefore, it does not have an #id. This is important because if you use code in the addition row that references #id, you may encounter unexpected behavior:
If the field is calculated by code and edited in the addition row and "code only on addition" is disabled — the value in the added row will be fixed, as it will be recalculated after addition and will differ from the value calculated during addition.
If the field is calculated by code and edited in the addition row and "code only on addition" is enabled — the value in the added row will be added considering that #id was equal to "":
= : str`"NUM -" ++ #id`)
// Without "code only on addition"
// Result in the addition row: NUM -
// Result after addition: NUM - [hand]
// With "code only on addition"
// Result in the addition row: NUM -
// Result after addition: NUM -
Therefore, it is not recommended to use id references for codes in tables where users can manually add rows.
When you add a row using the insert function, this is also relevant — if you use "code only on addition," then during its execution, id will be empty!
If you still need both the addition row and the id after addition, you need to add an action to the row addition:
If "code only on addition" is enabled:
=: recalculate(table: $#ntn; where: 'id' = #id; field: $#nf)
// Action code is executed after the creation of id
If "code only on addition" is disabled and the field is "editable on addition":
=: clear(table: $#ntn; where: 'id' = #id; field: $#nf)
// Action code is executed after the creation of id
These options do not solve the problem if you have subsequent field codes dependent on this field.
Therefore, the best option would be to construct the code without referencing the
idof the added row!