[Dolibarr-user] Multiple (and different) factures data

[Carlos Cesar Caballero Díaz]

Hi, we are trying to start using dolibarr but we are facing a problem, 
we have many factures models, this is not a problem because we can 
create many factures templates, but some of them depends on more of one 
variable, lets say:

Service A: Whe charge the service hourly, with a fixed price by hour.
With this kind of fracture there is no problem, we can create our 
factures and templates without problem

But

Service B: Whe charge the service depending of time and people, so, we 
charge hourly for each worker working in the service, for example:
The service cost is $2 hourly for each person, so, if it will require 10 
hours and have 5 workers the total cost will be $100 ($2 x 10h x 5w).
We need for this kind of service introduce two variables for the total 
price calculation, hours and workers, and it need to be reflected in our 
models, of course.

Is possible to add this kind of functionality without change the 
dolibarr core code? We look at the customFields module documentation 
(https://wiki.dolibarr.org/index.php/Module_CustomFields_Cases) and 
seems that using it we can add this kind of functionlity, but in the 
examples they are modifying core dolibarr code, something that we really 
want to avoid.

Greetings.