I am new to SharePoint, need some guide on the choosing the API.
I being read a lot of info last few days by its still very confusion to me. https://dev.office.com/sharepoint/docs/general-development/choose-the-right-api-set-in-sharepoint
My requirement: Create a custom ribbon button on list ribbon menu, when the user click, it will allow the user to select a (CSV/excel) file, to import the data to the list. I am using Share Online.
My question: 1. What type of development model option can I use? 1a. Sharepoint hosted - run on client side only (HTML, js, CSS), which might be my last option because to dealing with excel file it will be best in server side code.
1b. Self-hosted - run on an external server. I can only use CSOM (with .NET, js) on another IIS web application. But i don't have an additional web application to host it.
1c. Provisioned Azure Web Application - No sure how it can be done.
Is it that possible for me to use SSOM on Sharepoint Online? And which development model i can use?