Odoo13: How to assign followers to a record via Controller

In my webform controller, I am attempting to assign email addresses entered in a webform to a given record. This is the snippet of code in my controller responsible for that

if 'followers' in request.params:
            raw_emails = request.httprequest.form.get('followers').split(',')
            emails = [user.strip() for user in raw_emails] 
            #emails = ['[email protected]', '[email protected]',..]

            for email in emails:
                follower = request.env['res.users'].search(
                    [('email', '=', email)])
                if bool(follower):
                    reg = {
                        'res_id': new_ticket.id,
                        'res_model': 'helpdesk.ticket',
                        'partner_id': follower.id
                    }
                    request.env['mail.followers'].create(reg)
                else:
                    message = "TO DO: Add {} to the system and make the user a follower of this ticket".format(
                        email)
                    new_ticket.message_post(body=message)

With this I get strange results i.e after entering "user A" as a follower on the webform, "user B" gets added as a follower. I'm thinking the problem might be from the wrong user record being loaded into the follower variable but I'm not seeing why. Any feedback would be really appreciated.

Solution

You can use the message_subscribe method to add followers to a record set.

def message_subscribe(self, partner_ids=None, channel_ids=None, subtype_ids=None):
""" Main public API to add followers to a record set. Its main purpose is
to perform access rights checks before calling _message_subscribe. """

You have already an example in the account move, in message_new method that add a list of partners.

# Assign followers.
all_followers_ids = set(partner.id for partner in followers + senders + partners if is_internal_partner(partner))
move.message_subscribe(list(all_followers_ids))