settings_org: Add frontend to change wildcard_mention_policy.

We add dropdown for wildcard_mention_policy in organization
permissions page.

static/js/admin.js

@@ -59,6 +59,7 @@ exports.build_page = function () {
         realm_user_group_edit_policy: page_params.realm_user_group_edit_policy,
         USER_GROUP_EDIT_POLICY_MEMBERS: 1,
         realm_private_message_policy: page_params.realm_private_message_policy,
+        realm_wildcard_mention_policy: page_params.realm_wildcard_mention_policy,
         realm_name_changes_disabled: page_params.realm_name_changes_disabled,
         realm_email_changes_disabled: page_params.realm_email_changes_disabled,
         realm_avatar_changes_disabled: page_params.realm_avatar_changes_disabled,

static/js/server_events_dispatch.js

@@ -143,6 +143,7 @@ exports.dispatch_normal_event = function dispatch_normal_event(event) {
                 emails_restricted_to_domains: noop,
                 video_chat_provider: compose.update_video_chat_button_display,
                 waiting_period_threshold: noop,
+                wildcard_mention_policy: noop,
             };
             if (
                 event.op === "update" &&

static/js/settings_config.js

@@ -137,6 +137,43 @@ exports.private_message_policy_values = {
     },
 };
 
+exports.wildcard_mention_policy_values = {
+    by_everyone: {
+        order: 1,
+        code: 1,
+        description: i18n.t("Admins, members and guests"),
+    },
+    by_members: {
+        order: 2,
+        code: 2,
+        description: i18n.t("Admins and members"),
+    },
+    by_full_members: {
+        order: 3,
+        code: 3,
+        description: i18n.t("Admins and full members"),
+    },
+    // Until we add stream administrators, we mislabel this choice
+    // (which we intend to be the long-term default) as "Admins only"
+    // and don't offer the long-term "Admins only" option.
+    by_stream_admins_only: {
+        order: 4,
+        code: 4,
+        //  description: i18n.t("Organization and stream admins"),
+        description: i18n.t("Admins only"),
+    },
+    // by_admins_only: {
+    //     order: 5,
+    //     code: 5,
+    //     description: i18n.t("Admins only"),
+    // },
+    nobody: {
+        order: 6,
+        code: 6,
+        description: i18n.t("Nobody"),
+    },
+};
+
 const time_limit_dropdown_values = new Map([
     [
         "any_time",

static/js/settings_org.js

@@ -87,6 +87,9 @@ exports.get_organization_settings_options = () => {
     options.private_message_policy_values = exports.get_sorted_options_list(
         settings_config.private_message_policy_values,
     );
+    options.wildcard_mention_policy_values = exports.get_sorted_options_list(
+        settings_config.wildcard_mention_policy_values,
+    );
     return options;
 };
 
@@ -203,6 +206,7 @@ const simple_dropdown_properties = [
     "realm_private_message_policy",
     "realm_add_emoji_by_admins_only",
     "realm_user_invite_restriction",
+    "realm_wildcard_mention_policy",
 ];
 
 function set_property_dropdown_value(property_name) {

static/styles/settings.css

@@ -1543,7 +1543,8 @@ body:not(.night-mode) #settings_page .custom_user_field .datepicker {
 #id_realm_invite_to_stream_policy,
 #id_realm_org_join_restrictions,
 #id_realm_bot_creation_policy,
-#id_realm_user_invite_restriction {
+#id_realm_user_invite_restriction,
+#id_realm_wildcard_mention_policy {
     width: 100%;
 }
 

static/templates/settings/organization_permissions_admin.hbs

@@ -150,6 +150,13 @@
                         {{> dropdown_options_widget option_values=private_message_policy_values}}
                     </select>
                 </div>
+
+                <div class="input-group">
+                    <label for="realm_wildcard_mention_policy" class="dropdown-title">{{t "Who can use wildcard mentions in large streams" }}</label>
+                    <select name="realm_wildcard_mention_policy" id="id_realm_wildcard_mention_policy" class="prop-element" data-setting-widget-type="number">
+                        {{> dropdown_options_widget option_values=wildcard_mention_policy_values}}
+                    </select>
+                </div>
             </div>
         </div>
     </form>

templates/zerver/help/mention-a-user-or-group.md

@@ -49,8 +49,38 @@ notification. Silent mentions start with `@_` instead of `@`.
 ## Mention everyone on a stream
 
 You can mention everyone on a stream with the `@**all**` mention. Use
-sparingly!  Note that this will not notify anyone who has muted the
-stream, and users can disable receiving email/push notifications for
-these wildcard mentions, either
+sparingly! Used improperly, wildcard mentions can be annoying.
+
+Note that this will not notify anyone who has muted the stream, and
+users can disable receiving email/push notifications for these
+wildcard mentions, either
 [globally](/help/pm-mention-alert-notifications) or for [individual
 streams](/help/stream-notifications).
+
+### Restrictions on wildcard mentions
+
+Organization administrators can set a policy for which users are
+allowed to use wildcard mentions.
+
+Zulip allows anyone to use wildcard mentions in streams with at most
+15 subscribers.
+
+Organizations administrators can configure a policy for which classes
+of users are allowed to use wildcard mentions in streams with more
+than 15 subscribers.  The default allows only organization
+administrators to use wildcard mentions in large streams.
+
+Users permitted to use wildcard mentions by the organization's policy
+are warned that wildcard mentions result in everyone receiving email
+and mobile push notifications.
+
+{start_tabs}
+
+{settings_tab|organization-permissions}
+
+2. Under **Organization permissions**, configure
+   **Who can use wildcard mentions in large streams**.
+
+{!save-changes.md!}
+
+{end_tabs}

templates/zerver/help/moderating-open-organizations.md

@@ -24,6 +24,8 @@ Zulip has many features designed to simplify moderation:
   new users can take disruptive actions.
 * [Restrict email visibility](/help/restrict-visibility-of-email-addresses)
   to reduce the likelihood of off-platform spam.
+* [Restrict wildcard mentions](/help/mention-a-user-or-group#restrictions-on-wildcard-mentions)
+  so only moderators can mention everyone in your organization.
 
 ## Response