Multiples validations in multiples inputs

Hi community, I am working in a shinyapp that is connecting with a MariaDB and analyzing data from there. As part of this I have a requirement to do a CRUD app that allow to manage some tables in the DB (I never did this with shiny).

I was reading some information and seeing some examples that I found (specially the example uploaded by @barbara in Building CRUD with Shiny - #10 by Anantadinath ) and my objectives to start was the following:

1 - A package to connect with DB and to have all queries types. (Here I have all required methods to add,update,delete,get).

2 - A shiny module with a table that allow to add news entries, update the current entries and delete entries.

3 - Other shiny module for the formulary that will be used for edit/add news entries. This module must to contains validations for each field to add/edit.

And this is looking (as I am a new user, system only allow me to upload 1 img):

But I would like to improve the multiples validations in the inputs (length of characters, required input,etc) . I thought these alternatives:

a) Use of validation() and need() when the "submit" button is clicked and show all errors in input validations in a output above of the form. (This was applied in the example)

b) Use validation() and need(), and show each error under each input. This would imply to add a outputHtml for each input in UI.

c) To add the input validations in js and show in some part of the UI.

Someone have some other idea? or Do you know about some module to simplify the form validation?
I would like to simplify the code when I have 4-5 validations for input (I am also checking if same shortname exists in DB as example).

Thanks in advance!