CAP + Fiori Elements - Structure of app

[OliverGraetz37]

Hi everyone,

I am pretty new to all the cloud development topics and have been assigned a project where I have to migrate a Z-Cockpit to the cloud as a Side-By-Side Extension. I have been trying around a little and would like to clear up some doubts I have in terms of viability or to double-check if might not be going in a completely wrong direction.

Status Quo:

I have build a FE app using the list report template and connected it to a CAP Backend (OData V4) which is consuming an OData-Service (V2) from a S4HC system. This OData-service is exposing some CBOs as well as some finance related data associated to the main entity. 

Requirement:

On the FE's object page there is a table displaying a sub-entity to the main entity. The user needs to enter data somewhere so that per trigger action (table action?) I can use the input data as well as the initial data of the sub entity to A create a finance document (SAP Standard) from my cap backend and B update the sub entity (CBO) on the S4HC system. The input data is necessary for the FI document creation.

My approach

1. I was considering declaring a new associated sub entity to the sub entity (so a sub-sub entity) to make it appear in the table as well and then editable - so that the user can enter data - on custom action button trigger my cap action and pass the values to the CAP action that I need.

2. On click on one of the rows of the table I navigate to a custom page where I create some custom entry fields - let the user enter data - and on custom button click trigger the CAP action and pass the values to the CAP action (Not sure if the data of the sub entity's row can be acessed here?)

I would appreciate it a lot if you could guide me here and give me some tips whether I am taking the right approach here or if this sounds rather like a SAPUI5 Freestyle case to you and if it indeed a viable case for FE which of 1 or 2 would be preferable or even suggest a better approach to me.

Big thanks in advance and regards,

Oliver