stream_settings: Add 'Default stream' option in create stream UI.

In this commit, we introduce a new option in the stream creation
UI - a 'Default stream for new users' checkbox. By default, the
checkbox is set to 'off' and is only visible to admins. This
allow admins to easily designate a stream as the default stream
for new users during stream creation.

Fixes #24048.

api_docs/changelog.md

@@ -23,8 +23,11 @@ format used by the Zulip server that they are interacting with.
 **Feature level 200**
 
 * [`PATCH /streams/{stream_id}`](/api/update-stream): Added
-  `is_default_stream` parameter to add or remove the stream as a default
+  `is_default_stream` parameter to change whether the stream is a
-  stream for new users.
+  default stream for new users in the organization.
+* [`POST /users/me/subscriptions`](/api/subscribe): Added
+  `is_default_stream` parameter which determines whether any streams
+  created by this request will be default streams for new users.
 
 **Feature level 199**
 

version.py

@@ -33,7 +33,7 @@ DESKTOP_WARNING_VERSION = "5.9.3"
 # Changes should be accompanied by documentation explaining what the
 # new level means in api_docs/changelog.md, as well as "**Changes**"
 # entries in the endpoint's documentation in `zulip.yaml`.
-API_FEATURE_LEVEL = 199
+API_FEATURE_LEVEL = 200
 
 # Bump the minor PROVISION_VERSION to indicate that folks should provision
 # only when going from an old version of the code to a newer version. Bump

web/src/stream_create.js

@@ -217,6 +217,9 @@ function create_stream() {
     data.invite_only = JSON.stringify(invite_only);
     data.history_public_to_subscribers = JSON.stringify(history_public_to_subscribers);
 
+    const default_stream = $("#stream_creation_form .is_default_stream").prop("checked");
+    data.is_default_stream = JSON.stringify(default_stream);
+
     const stream_post_policy = Number.parseInt(
         $("#stream_creation_form select[name=stream-post-policy]").val(),
         10,
@@ -370,8 +373,10 @@ export function show_new_stream_modal() {
         true,
     );
 
-    // set default state for "announce stream" option.
+    // set default state for "announce stream" and "default stream" option.
+    $("#stream_creation_form .default-stream input").prop("checked", false);
     update_announce_stream_state();
+    stream_ui_updates.update_default_stream_and_stream_privacy_state($("#stream-creation"));
     clear_error_display();
 }
 
@@ -381,7 +386,14 @@ export function set_up_handlers() {
 
     const $container = $("#stream-creation").expectOne();
 
-    $container.on("change", ".stream-privacy-values input", update_announce_stream_state);
+    $container.on("change", ".stream-privacy-values input", () => {
+        update_announce_stream_state();
+        stream_ui_updates.update_default_stream_and_stream_privacy_state($container);
+    });
+
+    $container.on("change", ".default-stream input", () => {
+        stream_ui_updates.update_default_stream_and_stream_privacy_state($container);
+    });
 
     $container.on("click", ".finalize_create_stream", (e) => {
         e.preventDefault();

web/src/stream_settings_ui.js

@@ -717,6 +717,7 @@ export function setup_page(callback) {
             stream_privacy_policy_values: stream_data.stream_privacy_policy_values,
             stream_privacy_policy,
             stream_post_policy_values: stream_data.stream_post_policy_values,
+            check_default_stream: false,
             zulip_plan_is_not_limited: page_params.zulip_plan_is_not_limited,
             org_level_message_retention_setting:
                 stream_edit.get_display_text_for_realm_message_retention_setting(),

web/src/stream_ui_updates.js

@@ -115,6 +115,15 @@ export function update_regular_sub_settings(sub) {
 
 export function update_default_stream_and_stream_privacy_state($container) {
     const $default_stream = $container.find(".default-stream");
+    const is_stream_creation = $container.attr("id") === "stream-creation";
+
+    // In the stream creation UI, if the user is a non-admin hide the
+    // "Default stream for new users" widget
+    if (is_stream_creation && !page_params.is_admin) {
+        $default_stream.hide();
+        return;
+    }
+
     const privacy_type = $container.find("input[type=radio][name=privacy]:checked").val();
     const is_invite_only =
         privacy_type === "invite-only" || privacy_type === "invite-only-public-history";

web/templates/stream_settings/stream_types.hbs

@@ -16,17 +16,15 @@
     </div>
 </div>
 
-{{#if is_stream_edit}}
+<div class="default-stream">
-    <div class="default-stream">
+    {{> ../settings/settings_checkbox
-        {{> ../settings/settings_checkbox
+      prefix="id_"
-          prefix="id_"
+      setting_name="is_default_stream"
-          setting_name="is_default_stream"
+      is_checked=check_default_stream
-          is_checked=check_default_stream
+      label="Default stream for new users"
-          label="Default stream for new users"
+      help_link="/help/set-default-streams-for-new-users"
-          help_link="/help/set-default-streams-for-new-users"
+      }}
-          }}
+</div>
-    </div>
-{{/if}}
 
 <div class="input-group">
     <label class="dropdown-title">{{t 'Who can post to the stream?'}}

zerver/lib/streams.py

@@ -670,6 +670,7 @@ def list_to_streams(
     user_profile: UserProfile,
     autocreate: bool = False,
     unsubscribing_others: bool = False,
+    is_default_stream: bool = False,
 ) -> Tuple[List[Stream], List[Stream]]:
     """Converts list of dicts to a list of Streams, validating input in the process
 
@@ -736,6 +737,10 @@ def list_to_streams(
                 raise JsonableError(_("Insufficient permission"))
             if not invite_only and not user_profile.can_create_public_streams():
                 raise JsonableError(_("Insufficient permission"))
+            if is_default_stream and not user_profile.is_realm_admin:
+                raise JsonableError(_("Insufficient permission"))
+            if invite_only and is_default_stream:
+                raise JsonableError(_("A default stream cannot be private."))
 
         if not autocreate:
             raise JsonableError(

zerver/openapi/zulip.yaml

@@ -8657,6 +8657,21 @@ paths:
             type: boolean
             default: false
           example: true
+        - name: is_default_stream
+          in: query
+          description: |
+            This parameter determines whether any newly created streams will be
+            added as [default streams][default-streams] for new users joining
+            the organization.
+
+            [default-streams]: /help/set-default-streams-for-new-users
+
+            **Changes**: New in Zulip 8.0 (feature level 200). Previously, default stream status
+            could only be changed using the [dedicated API endpoint](/api/add-default-stream).
+          schema:
+            type: boolean
+            default: false
+          example: true
         - $ref: "#/components/parameters/HistoryPublicToSubscribers"
         - $ref: "#/components/parameters/StreamPostPolicy"
         - $ref: "#/components/parameters/MessageRetentionDays"

zerver/tests/test_subs.py

@@ -383,6 +383,47 @@ class TestCreateStreams(ZulipTestCase):
             if stream.name == "publictrywithouthistory":
                 self.assertTrue(stream.history_public_to_subscribers)
 
+    def test_add_stream_as_default_on_stream_creation(self) -> None:
+        user_profile = self.example_user("hamlet")
+        self.login_user(user_profile)
+        realm = user_profile.realm
+
+        post_data = {
+            "subscriptions": orjson.dumps(
+                [{"name": "default_stream", "description": "This stream is default for new users"}]
+            ).decode(),
+            "is_default_stream": orjson.dumps(True).decode(),
+        }
+        result = self.api_post(
+            user_profile, "/api/v1/users/me/subscriptions", post_data, subdomain="zulip"
+        )
+        self.assert_json_error(result, "Insufficient permission")
+
+        do_change_user_role(user_profile, UserProfile.ROLE_REALM_ADMINISTRATOR, acting_user=None)
+        result = self.api_post(
+            user_profile, "/api/v1/users/me/subscriptions", post_data, subdomain="zulip"
+        )
+        self.assert_json_success(result)
+        default_stream = get_stream("default_stream", realm)
+        self.assertTrue(default_stream.id in get_default_stream_ids_for_realm(realm.id))
+
+        post_data = {
+            "subscriptions": orjson.dumps(
+                [
+                    {
+                        "name": "private_default_stream",
+                        "description": "This stream is private and default for new users",
+                    }
+                ]
+            ).decode(),
+            "invite_only": orjson.dumps(True).decode(),
+            "is_default_stream": orjson.dumps(True).decode(),
+        }
+        result = self.api_post(
+            user_profile, "/api/v1/users/me/subscriptions", post_data, subdomain="zulip"
+        )
+        self.assert_json_error(result, "A default stream cannot be private.")
+
     def test_history_public_to_subscribers_zephyr_realm(self) -> None:
         realm = get_realm("zephyr")
 

zerver/views/streams.py

@@ -578,6 +578,7 @@ def add_subscriptions_backend(
     ),
     invite_only: bool = REQ(json_validator=check_bool, default=False),
     is_web_public: bool = REQ(json_validator=check_bool, default=False),
+    is_default_stream: bool = REQ(json_validator=check_bool, default=False),
     stream_post_policy: int = REQ(
         json_validator=check_int_in(Stream.STREAM_POST_POLICY_TYPES),
         default=Stream.STREAM_POST_POLICY_EVERYONE,
@@ -660,7 +661,9 @@ def add_subscriptions_backend(
     # Validation of the streams arguments, including enforcement of
     # can_create_streams policy and check_stream_name policy is inside
     # list_to_streams.
-    existing_streams, created_streams = list_to_streams(stream_dicts, user_profile, autocreate=True)
+    existing_streams, created_streams = list_to_streams(
+        stream_dicts, user_profile, autocreate=True, is_default_stream=is_default_stream
+    )
     authorized_streams, unauthorized_streams = filter_stream_authorization(
         user_profile, existing_streams
     )
@@ -682,6 +685,10 @@ def add_subscriptions_backend(
             _("You can only invite other Zephyr mirroring users to private streams.")
         )
 
+    if is_default_stream:
+        for stream in created_streams:
+            do_add_default_stream(stream)
+
     (subscribed, already_subscribed) = bulk_add_subscriptions(
         realm, streams, subscribers, acting_user=user_profile, color_map=color_map
     )