Option for whether to notify users when added to channel

[alya]

When someone adds another user to a channel, we send the user that was added a Notification Bot message to let them know. We should add an option for whether or not this message is sent. In particular, when bulk-adding users, the notification is often not desirable; it can also cause technical problems if hundreds or thousands of users are added at once.

To address this, we should make sending Notification Bot DMs optional when adding users to channels.

New setting details

• Checkbox option
• Option label: "Send notification message to users who are added"
• Placement:
  • Just below "Add subscribers" field on the channel Subscribers panel.
  • Just below "Choose subscribers" field when creating a channel.
• Option state:
  • Checked by default.
  • If more than 100 users are being added at once, option becomes unchecked and disabled. Tooltip: "Notification message cannot be sent when adding more than 100 users."
  • If the number of users being added goes below 100 after being higher, the option becomes re-enabled, but remains unchecked.

Notes:

• The help center will need to be updated:
  • https://zulip.com/help/add-or-remove-users-from-a-channel
  • https://zulip.com/help/create-a-channel

CZO thread

[kuv2707]

I am working on it

[alya]

@kuv2707 Please claim issues via Zulipbot when you pick them up.

[kuv2707]

@alya That doesn't work since I have other issues claimed.

[alya]

Have you tried? That rule should only apply before you have any commits merged.

[osujipius]

@zulipbot claim

[zulipbot]

@osujipius This issue cannot be claimed, as someone else is already working on it. Please see our contributor guide for advice on finding an issue to work on. Thanks!