FEATURE: optional attached chat channel for event (#728)

This defines a feature where event creators can opt for an associated chat channel
creation.

This is a staff only feature for now.

Co-authored-by: Joffrey JAFFEUX <j.jaffeux@gmail.com>

app/models/discourse_post_event/event.rb

@@ -3,18 +3,39 @@
 module DiscoursePostEvent
   class Event < ActiveRecord::Base
     PUBLIC_GROUP = "trust_level_0"
-
+    MIN_NAME_LENGTH = 5
+    MAX_NAME_LENGTH = 255
     self.table_name = "discourse_post_event_events"
-
     self.ignored_columns = %w[starts_at ends_at]
 
     has_many :event_dates, dependent: :destroy
+    # this is a cross plugin dependency, only called if chat is enabled
+    belongs_to :chat_channel, class_name: "Chat::Channel"
+    has_many :invitees, foreign_key: :post_id, dependent: :delete_all
+    belongs_to :post, foreign_key: :id
+
+    scope :visible, -> { where(deleted_at: nil) }
+
+    after_commit :destroy_topic_custom_field, on: %i[destroy]
+    after_commit :create_or_update_event_date, on: %i[create update]
+    before_save :chat_channel_sync
+
+    validate :raw_invitees_are_groups
+    validates :original_starts_at, presence: true
+    validates :name,
+              length: {
+                in: MIN_NAME_LENGTH..MAX_NAME_LENGTH,
+              },
+              unless: ->(event) { event.name.blank? }
+
+    validate :raw_invitees_length
+    validate :ends_before_start
+    validate :allowed_custom_fields
 
     def self.attributes_protected_by_default
       super - %w[id]
     end
 
-    after_commit :destroy_topic_custom_field, on: %i[destroy]
     def destroy_topic_custom_field
       if self.post && self.post.is_first_post?
         TopicCustomField.where(
@@ -29,7 +50,6 @@ module DiscoursePostEvent
       end
     end
 
-    after_commit :create_or_update_event_date, on: %i[create update]
     def create_or_update_event_date
       starts_at_changed = saved_change_to_original_starts_at
       ends_at_changed = saved_change_to_original_ends_at
@@ -84,11 +104,6 @@ module DiscoursePostEvent
       ActiveSupport::Duration::PARTS.any? { |part| part.to_s == input }
     end
 
-    has_many :invitees, foreign_key: :post_id, dependent: :delete_all
-    belongs_to :post, foreign_key: :id
-
-    scope :visible, -> { where(deleted_at: nil) }
-
     def expired?
       (ends_at || starts_at.end_of_day) <= Time.now
     end
@@ -103,8 +118,6 @@ module DiscoursePostEvent
         event_dates.order(:updated_at, :id).last&.ends_at
     end
 
-    validates :original_starts_at, presence: true
-
     def on_going_event_invitees
       return [] if !self.ends_at && self.starts_at < Time.now
 
@@ -117,15 +130,6 @@ module DiscoursePostEvent
       invitees.where(status: DiscoursePostEvent::Invitee.statuses[:going])
     end
 
-    MIN_NAME_LENGTH = 5
-    MAX_NAME_LENGTH = 255
-    validates :name,
-              length: {
-                in: MIN_NAME_LENGTH..MAX_NAME_LENGTH,
-              },
-              unless: ->(event) { event.name.blank? }
-
-    validate :raw_invitees_length
     def raw_invitees_length
       if self.raw_invitees && self.raw_invitees.length > 10
         errors.add(
@@ -135,7 +139,6 @@ module DiscoursePostEvent
       end
     end
 
-    validate :raw_invitees_are_groups
     def raw_invitees_are_groups
       if self.raw_invitees && User.select(:id).where(username: self.raw_invitees).limit(1).count > 0
         errors.add(
@@ -145,7 +148,6 @@ module DiscoursePostEvent
       end
     end
 
-    validate :ends_before_start
     def ends_before_start
       if self.original_starts_at && self.original_ends_at &&
            self.original_starts_at >= self.original_ends_at
@@ -156,7 +158,6 @@ module DiscoursePostEvent
       end
     end
 
-    validate :allowed_custom_fields
     def allowed_custom_fields
       allowed_custom_fields = SiteSetting.discourse_post_event_allowed_custom_fields.split("|")
       self.custom_fields.each do |key, value|
@@ -174,8 +175,12 @@ module DiscoursePostEvent
       attrs.map! do |attr|
         { post_id: self.id, created_at: timestamp, updated_at: timestamp }.merge(attr)
       end
+      result = self.invitees.insert_all!(attrs)
 
-      self.invitees.insert_all!(attrs)
+      # batch event does not call calleback
+      ChatChannelSync.sync(self) if chat_enabled?
+
+      result
     end
 
     def notify_invitees!(predefined_attendance: false)
@@ -309,6 +314,7 @@ module DiscoursePostEvent
           raw_invitees: event_params[:"allowed-groups"]&.split(","),
           minimal: event_params[:minimal],
           closed: event_params[:closed] || false,
+          chat_enabled: event_params[:"chat-enabled"]&.downcase == "true",
         }
 
         params[:custom_fields] = {}
@@ -364,6 +370,15 @@ module DiscoursePostEvent
       self.publish_update!
     end
 
+    def chat_channel_sync
+      if self.chat_enabled && self.chat_channel_id.blank? && post.last_editor_id.present?
+        DiscoursePostEvent::ChatChannelSync.sync(
+          self,
+          guardian: Guardian.new(User.find_by(id: post.last_editor_id)),
+        )
+      end
+    end
+
     def calculate_next_date(start_date: nil)
       localized_start = start_date || original_starts_at.in_time_zone(timezone)
 
@@ -408,4 +423,6 @@ end
 #  timezone           :string
 #  minimal            :boolean
 #  closed             :boolean          default(FALSE), not null
+#  chat_enabled       :boolean          default(FALSE), not null
+#  chat_channel_id    :bigint
 #

app/models/discourse_post_event/invitee.rb

@@ -10,9 +10,10 @@ module DiscoursePostEvent
     belongs_to :user
 
     default_scope { joins(:user).includes(:user).where("users.id IS NOT NULL") }
-
     scope :with_status, ->(status) { where(status: Invitee.statuses[status]) }
 
+    after_commit :sync_chat_channel_members
+
     def self.statuses
       @statuses ||= Enum.new(going: 0, interested: 1, not_going: 2)
     end
@@ -45,6 +46,11 @@ module DiscoursePostEvent
       )
     end
 
+    def sync_chat_channel_members
+      return if !self.event.chat_enabled?
+      ChatChannelSync.sync(self.event)
+    end
+
     def update_topic_tracking!
       topic_id = self.event.post.topic.id
       user_id = self.user.id

app/serializers/discourse_post_event/event_serializer.rb

@@ -30,6 +30,16 @@ module DiscoursePostEvent
     attributes :timezone
     attributes :url
     attributes :watching_invitee
+    attributes :chat_enabled
+    attributes :channel
+
+    def channel
+      ::Chat::ChannelSerializer.new(object.chat_channel, root: false, scope:)
+    end
+
+    def include_channel?
+      object.chat_enabled && defined?(::Chat::ChannelSerializer) && object.chat_channel.present?
+    end
 
     def can_act_on_discourse_post_event
       scope.can_act_on_discourse_post_event?(object)

app/services/discourse_post_event/chat_channel_sync.rb

@@ -0,0 +1,69 @@
+# frozen_string_literal: true
+#
+module DiscoursePostEvent
+  class ChatChannelSync
+    def self.sync(event, guardian: nil)
+      return if !event.chat_enabled?
+      if !event.chat_channel_id && guardian&.can_create_chat_channel?
+        ensure_chat_channel!(event, guardian:)
+      end
+      sync_chat_channel_members!(event) if event.chat_channel_id
+    end
+
+    def self.sync_chat_channel_members!(event)
+      missing_members_sql = <<~SQL
+        SELECT user_id
+        FROM discourse_post_event_invitees
+        WHERE post_id = :post_id
+        AND status in (:statuses)
+        AND user_id NOT IN (
+          SELECT user_id
+          FROM user_chat_channel_memberships
+          WHERE chat_channel_id = :chat_channel_id
+        )
+      SQL
+
+      missing_user_ids =
+        DB.query_single(
+          missing_members_sql,
+          post_id: event.post.id,
+          statuses: [
+            DiscoursePostEvent::Invitee.statuses[:going],
+            DiscoursePostEvent::Invitee.statuses[:interested],
+          ],
+          chat_channel_id: event.chat_channel_id,
+        )
+
+      if missing_user_ids.present?
+        ActiveRecord::Base.transaction do
+          missing_user_ids.each do |user_id|
+            event.chat_channel.user_chat_channel_memberships.create!(
+              user_id:,
+              chat_channel_id: event.chat_channel_id,
+              following: true,
+            )
+          end
+        end
+      end
+    end
+
+    def self.ensure_chat_channel!(event, guardian:)
+      name = event.name
+
+      channel = nil
+      Chat::CreateCategoryChannel.call(
+        guardian:,
+        params: {
+          name:,
+          category_id: event.post.topic.category_id,
+        },
+      ) do |result|
+        on_success { channel = result.channel }
+        on_failure { raise StandardError, result.inspect_steps }
+      end
+
+      # event creator will be a member of the channel
+      event.chat_channel_id = channel.id
+    end
+  end
+end

assets/javascripts/discourse/components/discourse-post-event/chat-channel.gjs

@@ -0,0 +1,15 @@
+import { LinkTo } from "@ember/routing";
+import ChannelTitle from "discourse/plugins/chat/discourse/components/channel-title";
+
+const DiscoursePostEventChatChannel = <template>
+  {{#if @event.channel}}
+    <section class="event__section event-chat-channel">
+      <span></span>
+      <LinkTo @route="chat.channel" @models={{@event.channel.routeModels}}>
+        <ChannelTitle @channel={{@event.channel}} />
+      </LinkTo>
+    </section>
+  {{/if}}
+</template>;
+
+export default DiscoursePostEventChatChannel;

assets/javascripts/discourse/components/discourse-post-event/index.gjs

@@ -7,6 +7,7 @@ import concatClass from "discourse/helpers/concat-class";
 import icon from "discourse/helpers/d-icon";
 import replaceEmoji from "discourse/helpers/replace-emoji";
 import routeAction from "discourse/helpers/route-action";
+import ChatChannel from "./chat-channel";
 import Creator from "./creator";
 import Dates from "./dates";
 import EventStatus from "./event-status";
@@ -124,10 +125,12 @@ export default class DiscoursePostEvent extends Component {
               Dates=(component Dates event=@event)
               Invitees=(component Invitees event=@event)
               Status=(component Status event=@event)
+              ChatChannel=(component ChatChannel event=@event)
             }}
           >
             <Url @url={{@event.url}} />
             <Dates @event={{@event}} />
+            <ChatChannel @event={{@event}} />
             <Invitees @event={{@event}} />
             {{#if @event.canUpdateAttendance}}
               <Status @event={{@event}} />

assets/javascripts/discourse/components/modal/post-event-builder.hbs

@@ -17,12 +17,14 @@
           @outletArgs={{hash event=@model.event}}
           @connectorTagName="div"
         >
-          <DateTimeInputRange
+          <EventField>
-            @from={{this.startsAt}}
+            <DateTimeInputRange
-            @to={{this.endsAt}}
+              @from={{this.startsAt}}
-            @timezone={{@model.event.timezone}}
+              @to={{this.endsAt}}
-            @onChange={{this.onChangeDates}}
+              @timezone={{@model.event.timezone}}
-          />
+              @onChange={{this.onChangeDates}}
+            />
+          </EventField>
 
           <EventField
             class="name"
@@ -223,6 +225,22 @@
             </label>
           </EventField>
 
+          {{#if this.showChat}}
+            <EventField
+              class="allow-chat"
+              @label="discourse_post_event.builder_modal.allow_chat.label"
+            >
+              <label class="checkbox-label">
+                <Input @type="checkbox" @checked={{@model.event.chatEnabled}} />
+                <span class="message">
+                  {{i18n
+                    "discourse_post_event.builder_modal.allow_chat.checkbox_label"
+                  }}
+                </span>
+              </label>
+            </EventField>
+          {{/if}}
+
           {{#if this.allowedCustomFields.length}}
             <EventField
               @label="discourse_post_event.builder_modal.custom_fields.label"

assets/javascripts/discourse/components/modal/post-event-builder.js

@@ -12,6 +12,7 @@ export default class PostEventBuilder extends Component {
   @service dialog;
   @service siteSettings;
   @service store;
+  @service currentUser;
 
   @tracked flash = null;
   @tracked isSaving = false;
@@ -131,6 +132,14 @@ export default class PostEventBuilder extends Component {
     return this.event.reminders?.length >= 5;
   }
 
+  get showChat() {
+    // As of June 2025, chat channel creation is only available to admins and moderators
+    return (
+      this.siteSettings.chat_enabled &&
+      (this.currentUser.admin || this.currentUser.moderator)
+    );
+  }
+
   @action
   groupFinder(term) {
     return Group.findAll({ term, ignore_automatic: true });

assets/javascripts/discourse/lib/raw-event-helper.js

@@ -33,6 +33,10 @@ export function buildParams(startsAt, endsAt, event, siteSettings) {
     params.minimal = "true";
   }
 
+  if (event.chatEnabled) {
+    params.chatEnabled = "true";
+  }
+
   if (endsAt) {
     params.end = moment(endsAt).tz(eventTz).format("YYYY-MM-DD HH:mm");
   }

assets/javascripts/discourse/models/discourse-post-event-event.js

@@ -3,6 +3,7 @@ import EmberObject from "@ember/object";
 import { TrackedArray } from "@ember-compat/tracked-built-ins";
 import { bind } from "discourse/lib/decorators";
 import User from "discourse/models/user";
+import ChatChannel from "discourse/plugins/chat/discourse/models/chat-channel";
 import DiscoursePostEventEventStats from "./discourse-post-event-event-stats";
 import DiscoursePostEventInvitee from "./discourse-post-event-invitee";
 
@@ -29,6 +30,7 @@ export default class DiscoursePostEventEvent {
   @tracked status;
   @tracked post;
   @tracked minimal;
+  @tracked chatEnabled;
   @tracked canUpdateAttendance;
   @tracked canActOnDiscoursePostEvent;
   @tracked shouldDisplayInvitees;
@@ -38,6 +40,7 @@ export default class DiscoursePostEventEvent {
   @tracked recurrence;
   @tracked recurrenceRule;
   @tracked customFields;
+  @tracked channel;
 
   @tracked _watchingInvitee;
   @tracked _sampleInvitees;
@@ -63,6 +66,7 @@ export default class DiscoursePostEventEvent {
     this.isExpired = args.is_expired;
     this.isStandalone = args.is_standalone;
     this.minimal = args.minimal;
+    this.chatEnabled = args.chat_enabled;
     this.recurrenceRule = args.recurrence_rule;
     this.recurrence = args.recurrence;
     this.canUpdateAttendance = args.can_update_attendance;
@@ -72,6 +76,9 @@ export default class DiscoursePostEventEvent {
     this.stats = args.stats;
     this.reminders = args.reminders;
     this.customFields = EmberObject.create(args.custom_fields || {});
+    if (args.channel) {
+      this.channel = ChatChannel.create(args.channel);
+    }
   }
 
   get watchingInvitee() {
@@ -138,6 +145,7 @@ export default class DiscoursePostEventEvent {
     this.isExpired = event.isExpired;
     this.isStandalone = event.isStandalone;
     this.minimal = event.minimal;
+    this.chatEnabled = event.chatEnabled;
     this.recurrenceRule = event.recurrenceRule;
     this.recurrence = event.recurrence;
     this.canUpdateAttendance = event.canUpdateAttendance;

assets/javascripts/discourse/pre-initializers/rich-editor-extension.js

@@ -12,6 +12,8 @@ const EVENT_ATTRIBUTES = {
   status: { default: "public" },
   timezone: { default: "UTC" },
   allowedGroups: { default: null },
+  chatEnabled: { default: null },
+  chatChannelId: { default: null },
 };
 
 /** @type {RichEditorExtension} */

assets/stylesheets/common/discourse-post-event.scss

@@ -350,6 +350,7 @@ $show-interested: inherit;
 
   .event-url,
   .event-dates,
+  .event-chat-channel,
   .event-invitees-avatars-container {
     display: grid;
     grid-template-columns: 3em 1fr;
@@ -357,7 +358,7 @@ $show-interested: inherit;
     align-items: center;
     height: min-content;
 
-    .d-icon {
+    > .d-icon {
       color: var(--primary-high);
       margin: 0 auto;
       padding: 0;
@@ -398,12 +399,13 @@ $show-interested: inherit;
   .event-invitees-icon {
     position: relative;
     display: flex;
+    margin: 0 auto;
   }
 
   .event-invitees-icon .going {
     font-size: var(--font-down-3);
     position: absolute;
-    right: 4px;
+    right: -2px;
     bottom: -8px;
     background: var(--secondary);
     border-radius: 50%;

config/locales/client.en.yml

@@ -460,6 +460,9 @@ en:
         minimal:
           label: "Minimal event"
           checkbox_label: "Hide Going/Not going buttons and invitees status"
+        allow_chat:
+          label: "Chat integration"
+          checkbox_label: "Create and manage event specific chat channel"
         url:
           label: "URL"
           placeholder: "Optional"

db/migrate/20250520042223_add_chat_fields_to_events.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+class AddChatFieldsToEvents < ActiveRecord::Migration[7.2]
+  def change
+    add_column :discourse_post_event_events, :chat_enabled, :boolean, default: false, null: false
+    add_column :discourse_post_event_events, :chat_channel_id, :bigint
+  end
+end

lib/discourse_post_event/event_parser.rb

@@ -14,6 +14,7 @@ module DiscoursePostEvent
       :timezone,
       :minimal,
       :closed,
+      :"chat-enabled",
     ]
 
     def self.extract_events(post)

spec/services/discourse_post_event/chat_channel_sync_spec.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+return if !defined?(Chat)
+
+describe DiscoursePostEvent::ChatChannelSync do
+  fab!(:user)
+  fab!(:admin)
+  fab!(:admin_post) { Fabricate(:post, user: admin) }
+
+  it "is able to create a chat channel and sync members" do
+    event = Fabricate(:event, chat_enabled: true, post: admin_post)
+
+    expect(event.chat_channel_id).to be_present
+    expect(event.chat_channel.name).to eq(event.name)
+    expect(event.chat_channel.user_chat_channel_memberships.count).to eq(1)
+    expect(event.chat_channel.user_chat_channel_memberships.first.user_id).to eq(admin.id)
+
+    event.create_invitees([user_id: user.id, status: DiscoursePostEvent::Invitee.statuses[:going]])
+    event.save!
+
+    expect(event.chat_channel.user_chat_channel_memberships.count).to eq(2)
+  end
+
+  it "will simply do nothing if user has no permission to create channel" do
+    post = Fabricate(:post, user: user)
+    event = Fabricate(:event, chat_enabled: true, post: post)
+
+    expect(event.chat_channel_id).to be_nil
+  end
+end

spec/system/post_event_spec.rb

@@ -105,22 +105,25 @@ describe "Post event", type: :system do
   it "persists changes" do
     visit "/new-topic"
     composer.fill_title("Test event with updates")
-    page.find(".toolbar-popup-menu-options .dropdown-select-box-header").click
+    find(".toolbar-popup-menu-options .dropdown-select-box-header").click
-    page.find(
+    find(
       ".toolbar-popup-menu-options [data-name='#{I18n.t("js.discourse_post_event.builder_modal.attach")}']",
     ).click
-    page.find(".d-modal input[name=status][value=private]").click
+    find(".d-modal input[name=status][value=private]").click
-    page.find(".d-modal input.group-selector").send_keys("test_")
+    find(".d-modal input.group-selector").send_keys("test_")
-    page.find(".autocomplete.ac-group").click
+    find(".autocomplete.ac-group").click
-    page.find(".d-modal .custom-field-input").fill_in(with: "custom value")
+    find(".d-modal .custom-field-input").fill_in(with: "custom value")
-    page.find(".d-modal .btn-primary").click
+    find(".d-modal .btn-primary").click
-    composer.submit
-    page.find(".discourse-post-event-more-menu-trigger").click
-    page.find(".edit-event").click
 
-    expect(page.find(".d-modal input[name=status][value=private]").checked?).to eq(true)
+    expect(page).to have_no_css(".d-modal")
-    expect(page.find(".d-modal")).to have_text("test_group")
+
-    expect(page.find(".d-modal .custom-field-input").value).to eq("custom value")
+    composer.submit
+    find(".discourse-post-event-more-menu-trigger").click
+    find(".edit-event").click
+
+    expect(find(".d-modal input[name=status][value=private]").checked?).to eq(true)
+    expect(find(".d-modal")).to have_text("test_group")
+    expect(find(".d-modal .custom-field-input").value).to eq("custom value")
   end
 
   context "when using bulk inline invite" do