I have being working with on-premise sharepoint 2013. and a lot of functionalities i have been doing were implemented inside Event Receivers when item added/updated.
Where inside Visual Studio 2012 Professional, i create the event receivers and using server-side object model SSOM i update certain fields, send API requests to external system , send emails, etc.
Now we are going to work with office 365 sharepoint, and as i know event receivers + serve-side object model are not available inside sharepoint online.
So let say i want to implement a scenario such as:- an item Priority will be set to "high" if the user who create the item is within the "Company Manager" security group.
Now inside SharePoint 2013 on-premise, i would create an event receiver using VS 2012, and using server-side object model will allow me to access the item fields , security groups , and then updates the item Priority field.
so inside sharepoint online what will be the appraoch i need to follow? which mimic Event Receivers & SSOM ?? Thanks