If we intend to customize the existing code as per our specific needs, is the documentation of existing code available?
Hello samiuzzafar
Functions are usually documented using PHPDoc comments.
You can develop an add-on module or plugin instead of editing core files, which has benefits of maintainability when it comes to upgrading.
Example add-on module here and see existing plugins for examples.
If you need new action hooks added to core to trigger your own actions, you can open a Merge Request on GitLab.
https://gitlab.com/francoisjacquet/rosariosis/-/blob/mobile/CONTRIBUTING.md#coding-standards
Thanks francoisjacquet for your prompt response! I will go through it and will get back to you, if needed.