How to add functionalities in base module?

I have created a custom app but unable to add the new functionalities.
So someone could please explain me how to add functionalities in existing or base module through custom app.
Please give example for this if possible.


You can add functionalities to your app by writting code :slight_smile:

I feel you need this
Give an example of what you are trying to do.

Here I have added a new custom field total material cost in project and I want to get data from database as a method of project class in project DOC type get the all data in form according to particular project you open, i want value of total material cost field with it, so is there any inheritance concept as without inheritance you can not load the value of parent one with custom.