Prevent download from Document Library

[Shibu Mathew]

How do I prevent user form downloading document from document library ? Turning off the Allow items from this site to be downloaded to offline clients? still allows the user to download files from the site

[#2 · Accepted solution]

You will need to use the limited access policy with InTune and Azure Active Directory to prevent the download options based on conditions. At the moment this would cover all sites rather than particular site collections but you can have a policy for on network vs internet connected.
https://cloudblogs.microsoft.com/enterprisemobility/2017/03/09/conditional-access-limited-access-pol...

[#3]

Forgot about the new conditional access policies, was on top of my mind from ignite but couldn't find anything on search so figured it wasn't released.

[#4]

I would require this option to be enabled only for specific sites. I do not want to restrict user access to specific device or network. As long they are connected to internet they should not have the option to download files.

Is there any way thru Java script or REST API that can set permission to restrict user's from downloading files ?