DEV: Refactor gjs topic-list (#29792)

Based on the initial review in #28934

app/assets/javascripts/discourse/app/components/topic-list/header.gjs

@@ -0,0 +1,26 @@
+const Header = <template>
+  <tr>
+    {{#each @columns as |entry|}}
+      <entry.value.header
+        @sortable={{@sortable}}
+        @activeOrder={{@order}}
+        @changeSort={{@changeSort}}
+        @ascending={{@ascending}}
+        @category={{@category}}
+        @name={{@listTitle}}
+        @bulkSelectEnabled={{@bulkSelectEnabled}}
+        @showBulkToggle={{@toggleInTitle}}
+        @canBulkSelect={{@canBulkSelect}}
+        @canDoBulkActions={{@canDoBulkActions}}
+        @showTopicsAndRepliesToggle={{@showTopicsAndRepliesToggle}}
+        @newListSubset={{@newListSubset}}
+        @newRepliesCount={{@newRepliesCount}}
+        @newTopicsCount={{@newTopicsCount}}
+        @bulkSelectHelper={{@bulkSelectHelper}}
+        @changeNewListSubset={{@changeNewListSubset}}
+      />
+    {{/each}}
+  </tr>
+</template>;
+
+export default Header;

app/assets/javascripts/discourse/app/components/topic-list/header/activity-cell.gjs

@@ -0,0 +1,15 @@
+import SortableColumn from "./sortable-column";
+
+const ActivityCell = <template>
+  <SortableColumn
+    @sortable={{@sortable}}
+    @number="true"
+    @order="activity"
+    @activeOrder={{@activeOrder}}
+    @changeSort={{@changeSort}}
+    @ascending={{@ascending}}
+    @name="activity"
+  />
+</template>;
+
+export default ActivityCell;

app/assets/javascripts/discourse/app/components/topic-list/header/bulk-select-cell.gjs

@@ -0,0 +1,19 @@
+import { on } from "@ember/modifier";
+import icon from "discourse-common/helpers/d-icon";
+import { i18n } from "discourse-i18n";
+
+const BulkSelectCell = <template>
+  <th class="bulk-select topic-list-data">
+    {{#if @canBulkSelect}}
+      <button
+        {{on "click" @bulkSelectHelper.toggleBulkSelect}}
+        title={{i18n "topics.bulk.toggle"}}
+        class="btn-flat bulk-select"
+      >
+        {{icon "list-check"}}
+      </button>
+    {{/if}}
+  </th>
+</template>;
+
+export default BulkSelectCell;

app/assets/javascripts/discourse/app/components/topic-list/header/likes-cell.gjs

@@ -0,0 +1,15 @@
+import SortableColumn from "./sortable-column";
+
+const LikesCell = <template>
+  <SortableColumn
+    @sortable={{@sortable}}
+    @number="true"
+    @order="likes"
+    @activeOrder={{@activeOrder}}
+    @changeSort={{@changeSort}}
+    @ascending={{@ascending}}
+    @name="likes"
+  />
+</template>;
+
+export default LikesCell;

app/assets/javascripts/discourse/app/components/topic-list/header/op-likes-cell.gjs

@@ -0,0 +1,15 @@
+import SortableColumn from "./sortable-column";
+
+const OpLikesCell = <template>
+  <SortableColumn
+    @sortable={{@sortable}}
+    @number="true"
+    @order="op_likes"
+    @activeOrder={{@activeOrder}}
+    @changeSort={{@changeSort}}
+    @ascending={{@ascending}}
+    @name="likes"
+  />
+</template>;
+
+export default OpLikesCell;

app/assets/javascripts/discourse/app/components/topic-list/header/posters-cell.gjs

@@ -0,0 +1,16 @@
+import { i18n } from "discourse-i18n";
+import SortableColumn from "./sortable-column";
+
+const PostersCell = <template>
+  <SortableColumn
+    @order="posters"
+    @activeOrder={{@activeOrder}}
+    @changeSort={{@changeSort}}
+    @ascending={{@ascending}}
+    @name="posters"
+    @screenreaderOnly={{true}}
+    aria-label={{i18n "category.sort_options.posters"}}
+  />
+</template>;
+
+export default PostersCell;

app/assets/javascripts/discourse/app/components/topic-list/header/replies-cell.gjs

@@ -0,0 +1,15 @@
+import SortableColumn from "./sortable-column";
+
+const RepliesCell = <template>
+  <SortableColumn
+    @sortable={{@sortable}}
+    @number="true"
+    @order="posts"
+    @activeOrder={{@activeOrder}}
+    @changeSort={{@changeSort}}
+    @ascending={{@ascending}}
+    @name="replies"
+  />
+</template>;
+
+export default RepliesCell;

app/assets/javascripts/discourse/app/components/topic-list/header/sortable-column.gjs

@@ -10,7 +10,7 @@ import concatClass from "discourse/helpers/concat-class";
 import icon from "discourse-common/helpers/d-icon";
 import { i18n } from "discourse-i18n";
 
-export default class TopicListHeaderColumn extends Component {
+export default class SortableColumn extends Component {
   @service router;
 
   get localizedName() {
@@ -49,7 +49,8 @@ export default class TopicListHeaderColumn extends Component {
   }
 
   @action
-  onClick() {
+  onClick(event) {
+    event.preventDefault();
     this.args.changeSort(this.args.order);
   }
 

app/assets/javascripts/discourse/app/components/topic-list/header/topic-cell.gjs

@@ -0,0 +1,24 @@
+import SortableColumn from "./sortable-column";
+
+const TopicCell = <template>
+  <SortableColumn
+    @order="default"
+    @category={{@category}}
+    @activeOrder={{@activeOrder}}
+    @changeSort={{@changeSort}}
+    @ascending={{@ascending}}
+    @name={{@name}}
+    @bulkSelectEnabled={{@bulkSelectEnabled}}
+    @showBulkToggle={{@showBulkToggle}}
+    @canBulkSelect={{@canBulkSelect}}
+    @canDoBulkActions={{@canDoBulkActions}}
+    @showTopicsAndRepliesToggle={{@showTopicsAndRepliesToggle}}
+    @newListSubset={{@newListSubset}}
+    @newRepliesCount={{@newRepliesCount}}
+    @newTopicsCount={{@newTopicsCount}}
+    @bulkSelectHelper={{@bulkSelectHelper}}
+    @changeNewListSubset={{@changeNewListSubset}}
+  />
+</template>;
+
+export default TopicCell;

app/assets/javascripts/discourse/app/components/topic-list/header/views-cell.gjs

@@ -0,0 +1,15 @@
+import SortableColumn from "./sortable-column";
+
+const ViewsCell = <template>
+  <SortableColumn
+    @sortable={{@sortable}}
+    @number="true"
+    @order="views"
+    @activeOrder={{@activeOrder}}
+    @changeSort={{@changeSort}}
+    @ascending={{@ascending}}
+    @name="views"
+  />
+</template>;
+
+export default ViewsCell;

app/assets/javascripts/discourse/app/components/topic-list/item.gjs

@@ -6,13 +6,9 @@ import didInsert from "@ember/render-modifiers/modifiers/did-insert";
 import { next } from "@ember/runloop";
 import { service } from "@ember/service";
 import { modifier } from "ember-modifier";
-import { eq, gt } from "truth-helpers";
+import { eq } from "truth-helpers";
 import PluginOutlet from "discourse/components/plugin-outlet";
-import ActivityColumn from "discourse/components/topic-list/activity-column";
 import PostCountOrBadges from "discourse/components/topic-list/post-count-or-badges";
-import PostersColumn from "discourse/components/topic-list/posters-column";
-import PostsCountColumn from "discourse/components/topic-list/posts-count-column";
-import TopicCell from "discourse/components/topic-list/topic-cell";
 import TopicExcerpt from "discourse/components/topic-list/topic-excerpt";
 import TopicLink from "discourse/components/topic-list/topic-link";
 import TopicStatus from "discourse/components/topic-status";
@@ -22,14 +18,12 @@ import categoryLink from "discourse/helpers/category-link";
 import concatClass from "discourse/helpers/concat-class";
 import discourseTags from "discourse/helpers/discourse-tags";
 import formatDate from "discourse/helpers/format-date";
-import number from "discourse/helpers/number";
 import topicFeaturedLink from "discourse/helpers/topic-featured-link";
 import { wantsNewWindow } from "discourse/lib/intercept-click";
 import DiscourseURL from "discourse/lib/url";
-import icon from "discourse-common/helpers/d-icon";
 import { i18n } from "discourse-i18n";
 
-export default class TopicListItem extends Component {
+export default class Item extends Component {
   @service historyStore;
   @service site;
   @service siteSettings;
@@ -119,13 +113,11 @@ export default class TopicListItem extends Component {
     if (e.target.checked) {
       this.args.selected.addObject(this.args.topic);
 
-      if (this.args.lastCheckedElementId && e.shiftKey) {
+      if (this.args.bulkSelectHelper.lastCheckedElementId && e.shiftKey) {
-        const bulkSelects = Array.from(
+        const bulkSelects = [...document.querySelectorAll("input.bulk-select")];
-          document.querySelectorAll("input.bulk-select")
-        );
         const from = bulkSelects.indexOf(e.target);
         const to = bulkSelects.findIndex(
-          (el) => el.id === this.args.lastCheckedElementId
+          (el) => el.id === this.args.bulkSelectHelper.lastCheckedElementId
         );
         const start = Math.min(from, to);
         const end = Math.max(from, to);
@@ -136,10 +128,10 @@ export default class TopicListItem extends Component {
           .forEach((checkbox) => checkbox.click());
       }
 
-      this.args.updateLastCheckedElementId(e.target.id);
+      this.args.bulkSelectHelper.lastCheckedElementId = e.target.id;
     } else {
       this.args.selected.removeObject(this.args.topic);
-      this.args.updateLastCheckedElementId(null);
+      this.args.bulkSelectHelper.lastCheckedElementId = null;
     }
   }
 
@@ -223,78 +215,20 @@ export default class TopicListItem extends Component {
         @outletArgs={{hash topic=@topic}}
       />
       {{#if this.site.desktopView}}
-        {{! TODO: column DAG "topic-list-before-columns" }}
+        {{#each @columns as |entry|}}
-
+          <entry.value.item
-        {{#if @bulkSelectEnabled}}
-          <td class="bulk-select topic-list-data">
-            <label for="bulk-select-{{@topic.id}}">
-              <input
-                {{on "click" this.onBulkSelectToggle}}
-                checked={{this.isSelected}}
-                type="checkbox"
-                id="bulk-select-{{@topic.id}}"
-                class="bulk-select"
-              />
-            </label>
-          </td>
-        {{/if}}
-
-        <TopicCell
             @topic={{@topic}}
+            @bulkSelectEnabled={{@bulkSelectEnabled}}
+            @onBulkSelectToggle={{this.onBulkSelectToggle}}
+            @isSelected={{this.isSelected}}
             @showTopicPostBadges={{@showTopicPostBadges}}
             @hideCategory={{@hideCategory}}
             @tagsForUser={{@tagsForUser}}
             @expandPinned={{this.expandPinned}}
           />
-
+        {{/each}}
-        <PluginOutlet
-          @name="topic-list-after-main-link"
-          @outletArgs={{hash topic=@topic}}
-        />
-
-        {{#if @showPosters}}
-          <PostersColumn @posters={{@topic.featuredUsers}} />
-        {{/if}}
-
-        <PostsCountColumn @topic={{@topic}} />
-
-        {{#if @showLikes}}
-          <td class="num likes topic-list-data">
-            {{#if (gt @topic.like_count 0)}}
-              <a href={{@topic.summaryUrl}}>
-                {{number @topic.like_count}}
-                {{icon "heart"}}
-              </a>
-            {{/if}}
-          </td>
-        {{/if}}
-
-        {{#if @showOpLikes}}
-          <td class="num likes">
-            {{#if (gt @topic.op_like_count 0)}}
-              <a href={{@topic.summaryUrl}}>
-                {{number @topic.op_like_count}}
-                {{icon "heart"}}
-              </a>
-            {{/if}}
-          </td>
-        {{/if}}
-
-        <td class={{concatClass "num views topic-list-data" @topic.viewsHeat}}>
-          <PluginOutlet
-            @name="topic-list-before-view-count"
-            @outletArgs={{hash topic=@topic}}
-          />
-          {{number @topic.views numberKey="views_long"}}
-        </td>
-
-        <ActivityColumn @topic={{@topic}} class="num topic-list-data" />
-
-        {{! TODO: column DAG "topic-list-after-columns" }}
       {{else}}
         <td class="topic-list-data">
-          {{! TODO: column DAG "topic-list-before-columns" }}
-
           <div class="pull-left">
             {{#if @bulkSelectEnabled}}
               <label for="bulk-select-{{@topic.id}}">

app/assets/javascripts/discourse/app/components/topic-list/item/activity-cell.gjs

@@ -5,20 +5,17 @@ import coldAgeClass from "discourse/helpers/cold-age-class";
 import concatClass from "discourse/helpers/concat-class";
 import formatDate from "discourse/helpers/format-date";
 
-const ActivityColumn = <template>
+const ActivityCell = <template>
   <td
     title={{htmlSafe @topic.bumpedAtTitle}}
     class={{concatClass
-      "activity"
+      "activity num topic-list-data"
       (coldAgeClass @topic.createdAt startDate=@topic.bumpedAt class="")
     }}
-    ...attributes
   >
-    <a
+    <a href={{@topic.lastPostUrl}} class="post-activity">
-      href={{@topic.lastPostUrl}}
+      {{~! no whitespace ~}}
-      class="post-activity"
+      <PluginOutlet
-    >{{! no whitespace
-        }}<PluginOutlet
         @name="topic-list-before-relative-date"
         @outletArgs={{hash topic=@topic}}
       />
@@ -26,4 +23,5 @@ const ActivityColumn = <template>
     </a>
   </td>
 </template>;
-export default ActivityColumn;
+
+export default ActivityCell;

app/assets/javascripts/discourse/app/components/topic-list/item/bulk-select-cell.gjs

@@ -0,0 +1,17 @@
+import { on } from "@ember/modifier";
+
+const BulkSelectCell = <template>
+  <td class="bulk-select topic-list-data">
+    <label for="bulk-select-{{@topic.id}}">
+      <input
+        {{on "click" @onBulkSelectToggle}}
+        checked={{@isSelected}}
+        type="checkbox"
+        id="bulk-select-{{@topic.id}}"
+        class="bulk-select"
+      />
+    </label>
+  </td>
+</template>;
+
+export default BulkSelectCell;

app/assets/javascripts/discourse/app/components/topic-list/item/likes-cell.gjs

@@ -0,0 +1,16 @@
+import { gt } from "truth-helpers";
+import number from "discourse/helpers/number";
+import icon from "discourse-common/helpers/d-icon";
+
+const LikesCell = <template>
+  <td class="num likes topic-list-data">
+    {{#if (gt @topic.like_count 0)}}
+      <a href={{@topic.summaryUrl}}>
+        {{number @topic.like_count}}
+        {{icon "heart"}}
+      </a>
+    {{/if}}
+  </td>
+</template>;
+
+export default LikesCell;

app/assets/javascripts/discourse/app/components/topic-list/item/op-likes-cell.gjs

@@ -0,0 +1,16 @@
+import { gt } from "truth-helpers";
+import number from "discourse/helpers/number";
+import icon from "discourse-common/helpers/d-icon";
+
+const OpLikesCell = <template>
+  <td class="num likes">
+    {{#if (gt @topic.op_like_count 0)}}
+      <a href={{@topic.summaryUrl}}>
+        {{number @topic.op_like_count}}
+        {{icon "heart"}}
+      </a>
+    {{/if}}
+  </td>
+</template>;
+
+export default OpLikesCell;

app/assets/javascripts/discourse/app/components/topic-list/item/posters-cell.gjs

@@ -1,8 +1,8 @@
 import avatar from "discourse/helpers/avatar";
 
-const PostersColumn = <template>
+const PostersCell = <template>
   <td class="posters topic-list-data">
-    {{#each @posters as |poster|}}
+    {{#each @topic.featuredUsers as |poster|}}
       {{#if poster.moreCount}}
         <a class="posters-more-count">{{poster.moreCount}}</a>
       {{else}}
@@ -22,4 +22,4 @@ const PostersColumn = <template>
   </td>
 </template>;
 
-export default PostersColumn;
+export default PostersCell;

app/assets/javascripts/discourse/app/components/topic-list/item/replies-cell.gjs

@@ -6,7 +6,7 @@ import element from "discourse/helpers/element";
 import number from "discourse/helpers/number";
 import I18n from "discourse-i18n";
 
-export default class PostsCountColumn extends Component {
+export default class RepliesCell extends Component {
   @service siteSettings;
 
   get ratio() {

app/assets/javascripts/discourse/app/components/topic-list/item/views-cell.gjs

@@ -0,0 +1,16 @@
+import { hash } from "@ember/helper";
+import PluginOutlet from "discourse/components/plugin-outlet";
+import concatClass from "discourse/helpers/concat-class";
+import number from "discourse/helpers/number";
+
+const ViewsCell = <template>
+  <td class={{concatClass "num views topic-list-data" @topic.viewsHeat}}>
+    <PluginOutlet
+      @name="topic-list-before-view-count"
+      @outletArgs={{hash topic=@topic}}
+    />
+    {{number @topic.views numberKey="views_long"}}
+  </td>
+</template>;
+
+export default ViewsCell;

app/assets/javascripts/discourse/app/components/topic-list/latest-topic-list-item.gjs

@@ -1,7 +1,7 @@
 import Component from "@glimmer/component";
 import { concat, hash } from "@ember/helper";
 import PluginOutlet from "discourse/components/plugin-outlet";
-import PostsCountColumn from "discourse/components/topic-list/posts-count-column";
+import ItemRepliesCell from "discourse/components/topic-list/item/replies-cell";
 import TopicPostBadges from "discourse/components/topic-post-badges";
 import TopicStatus from "discourse/components/topic-status";
 import UserAvatarFlair from "discourse/components/user-avatar-flair";
@@ -75,7 +75,7 @@ export default class LatestTopicListItem extends Component {
           @outletArgs={{hash topic=@topic}}
         />
 
-        <PostsCountColumn @topic={{@topic}} @tagName="div" />
+        <ItemRepliesCell @topic={{@topic}} @tagName="div" />
 
         <div class="topic-last-activity">
           <a

app/assets/javascripts/discourse/app/components/topic-list/list.gjs

@@ -1,18 +1,109 @@
 import Component from "@glimmer/component";
-import { tracked } from "@glimmer/tracking";
+import { cached } from "@glimmer/tracking";
-import { fn, hash } from "@ember/helper";
+import { hash } from "@ember/helper";
 import { service } from "@ember/service";
 import { eq, or } from "truth-helpers";
 import PluginOutlet from "discourse/components/plugin-outlet";
-import TopicListHeader from "discourse/components/topic-list/topic-list-header";
+import Header from "discourse/components/topic-list/header";
-import TopicListItem from "discourse/components/topic-list/topic-list-item";
+import Item from "discourse/components/topic-list/item";
 import concatClass from "discourse/helpers/concat-class";
+import DAG from "discourse/lib/dag";
+import { applyValueTransformer } from "discourse/lib/transformer";
 import { i18n } from "discourse-i18n";
+import HeaderActivityCell from "./header/activity-cell";
+import HeaderBulkSelectCell from "./header/bulk-select-cell";
+import HeaderLikesCell from "./header/likes-cell";
+import HeaderOpLikesCell from "./header/op-likes-cell";
+import HeaderPostersCell from "./header/posters-cell";
+import HeaderRepliesCell from "./header/replies-cell";
+import HeaderTopicCell from "./header/topic-cell";
+import HeaderViewsCell from "./header/views-cell";
+import ItemActivityCell from "./item/activity-cell";
+import ItemBulkSelectCell from "./item/bulk-select-cell";
+import ItemLikesCell from "./item/likes-cell";
+import ItemOpLikesCell from "./item/op-likes-cell";
+import ItemPostersCell from "./item/posters-cell";
+import ItemRepliesCell from "./item/replies-cell";
+import ItemTopicCell from "./item/topic-cell";
+import ItemViewsCell from "./item/views-cell";
 
 export default class TopicList extends Component {
   @service currentUser;
+  @service topicTrackingState;
 
-  @tracked lastCheckedElementId;
+  @cached
+  get columns() {
+    const defaultColumns = new DAG({
+      // Allow customizations to replace just a header cell or just an item cell
+      onReplaceItem(_, newValue, oldValue) {
+        newValue.header ??= oldValue.header;
+        newValue.item ??= oldValue.item;
+      },
+    });
+
+    if (this.bulkSelectEnabled) {
+      defaultColumns.add("bulk-select", {
+        header: HeaderBulkSelectCell,
+        item: ItemBulkSelectCell,
+      });
+    }
+
+    defaultColumns.add("topic", {
+      header: HeaderTopicCell,
+      item: ItemTopicCell,
+    });
+
+    if (this.args.showPosters) {
+      defaultColumns.add("posters", {
+        header: HeaderPostersCell,
+        item: ItemPostersCell,
+      });
+    }
+
+    defaultColumns.add("replies", {
+      header: HeaderRepliesCell,
+      item: ItemRepliesCell,
+    });
+
+    if (this.args.order === "likes") {
+      defaultColumns.add("likes", {
+        header: HeaderLikesCell,
+        item: ItemLikesCell,
+      });
+    } else if (this.args.order === "op_likes") {
+      defaultColumns.add("op-likes", {
+        header: HeaderOpLikesCell,
+        item: ItemOpLikesCell,
+      });
+    }
+
+    defaultColumns.add("views", {
+      header: HeaderViewsCell,
+      item: ItemViewsCell,
+    });
+
+    defaultColumns.add("activity", {
+      header: HeaderActivityCell,
+      item: ItemActivityCell,
+    });
+
+    const self = this;
+    const context = {
+      get category() {
+        return self.topicTrackingState.get("filterCategory");
+      },
+
+      get filter() {
+        return self.topicTrackingState.get("filter");
+      },
+    };
+
+    return applyValueTransformer(
+      "topic-list-columns",
+      defaultColumns,
+      context
+    ).resolve();
+  }
 
   get selected() {
     return this.args.bulkSelectHelper?.selected;
@@ -34,12 +125,8 @@ export default class TopicList extends Component {
     return !!this.args.changeSort;
   }
 
-  get showLikes() {
+  get showTopicPostBadges() {
-    return this.args.order === "likes";
+    return this.args.showTopicPostBadges ?? true;
-  }
-
-  get showOpLikes() {
-    return this.args.order === "op_likes";
   }
 
   get lastVisitedTopic() {
@@ -83,10 +170,6 @@ export default class TopicList extends Component {
     return lastVisitedTopic;
   }
 
-  get showTopicPostBadges() {
-    return this.args.showTopicPostBadges ?? true;
-  }
-
   <template>
     {{! template-lint-disable table-groups }}
     <table
@@ -97,21 +180,19 @@ export default class TopicList extends Component {
     >
       <caption class="sr-only">{{i18n "sr_topic_list_caption"}}</caption>
       <thead class="topic-list-header">
-        <TopicListHeader
+        <Header
+          @columns={{this.columns}}
           @canBulkSelect={{@canBulkSelect}}
           @toggleInTitle={{this.toggleInTitle}}
           @category={{@category}}
           @hideCategory={{@hideCategory}}
-          @showPosters={{@showPosters}}
-          @showLikes={{this.showLikes}}
-          @showOpLikes={{this.showOpLikes}}
           @order={{@order}}
           @changeSort={{@changeSort}}
           @ascending={{@ascending}}
           @sortable={{this.sortable}}
           @listTitle={{or @listTitle "topic.title"}}
-          @bulkSelectEnabled={{this.bulkSelectEnabled}}
           @bulkSelectHelper={{@bulkSelectHelper}}
+          @bulkSelectEnabled={{this.bulkSelectEnabled}}
           @canDoBulkActions={{this.canDoBulkActions}}
           @showTopicsAndRepliesToggle={{@showTopicsAndRepliesToggle}}
           @newListSubset={{@newListSubset}}
@@ -135,20 +216,17 @@ export default class TopicList extends Component {
 
       <tbody class="topic-list-body">
         {{#each @topics as |topic index|}}
-          <TopicListItem
+          <Item
+            @columns={{this.columns}}
             @topic={{topic}}
+            @bulkSelectHelper={{@bulkSelectHelper}}
             @bulkSelectEnabled={{this.bulkSelectEnabled}}
             @showTopicPostBadges={{this.showTopicPostBadges}}
             @hideCategory={{@hideCategory}}
-            @showPosters={{@showPosters}}
-            @showLikes={{this.showLikes}}
-            @showOpLikes={{this.showOpLikes}}
             @expandGloballyPinned={{@expandGloballyPinned}}
             @expandAllPinned={{@expandAllPinned}}
             @lastVisitedTopic={{this.lastVisitedTopic}}
             @selected={{this.selected}}
-            @lastCheckedElementId={{this.lastCheckedElementId}}
-            @updateLastCheckedElementId={{fn (mut this.lastCheckedElementId)}}
             @tagsForUser={{@tagsForUser}}
             @focusLastVisitedTopic={{@focusLastVisitedTopic}}
             @index={{index}}

app/assets/javascripts/discourse/app/components/topic-list/post-count-or-badges.gjs

@@ -1,5 +1,5 @@
 import { and } from "truth-helpers";
-import PostsCountColumn from "discourse/components/topic-list/posts-count-column";
+import ItemRepliesCell from "discourse/components/topic-list/item/replies-cell";
 import TopicPostBadges from "discourse/components/topic-post-badges";
 
 const PostCountOrBadges = <template>
@@ -10,7 +10,7 @@ const PostCountOrBadges = <template>
       @url={{@topic.lastUnreadUrl}}
     />
   {{else}}
-    <PostsCountColumn @topic={{@topic}} @tagName="div" />
+    <ItemRepliesCell @topic={{@topic}} @tagName="div" />
   {{/if}}
 </template>;
 

app/assets/javascripts/discourse/app/components/topic-list/topic-list-header.gjs

@@ -1,116 +0,0 @@
-import { on } from "@ember/modifier";
-import PluginOutlet from "discourse/components/plugin-outlet";
-import TopicListHeaderColumn from "discourse/components/topic-list/topic-list-header-column";
-import icon from "discourse-common/helpers/d-icon";
-import { i18n } from "discourse-i18n";
-
-const TopicListHeader = <template>
-  <tr>
-    <PluginOutlet @name="topic-list-header-before" />
-
-    {{#if @bulkSelectEnabled}}
-      <th class="bulk-select topic-list-data">
-        {{#if @canBulkSelect}}
-          <button
-            {{on "click" @bulkSelectHelper.toggleBulkSelect}}
-            title={{i18n "topics.bulk.toggle"}}
-            class="btn-flat bulk-select"
-          >
-            {{icon "list-check"}}
-          </button>
-        {{/if}}
-      </th>
-    {{/if}}
-
-    <TopicListHeaderColumn
-      @order="default"
-      @category={{@category}}
-      @activeOrder={{@order}}
-      @changeSort={{@changeSort}}
-      @ascending={{@ascending}}
-      @name={{@listTitle}}
-      @bulkSelectEnabled={{@bulkSelectEnabled}}
-      @showBulkToggle={{@toggleInTitle}}
-      @canBulkSelect={{@canBulkSelect}}
-      @canDoBulkActions={{@canDoBulkActions}}
-      @showTopicsAndRepliesToggle={{@showTopicsAndRepliesToggle}}
-      @newListSubset={{@newListSubset}}
-      @newRepliesCount={{@newRepliesCount}}
-      @newTopicsCount={{@newTopicsCount}}
-      @bulkSelectHelper={{@bulkSelectHelper}}
-      @changeNewListSubset={{@changeNewListSubset}}
-    />
-
-    <PluginOutlet @name="topic-list-header-after-main-link" />
-
-    {{#if @showPosters}}
-      <TopicListHeaderColumn
-        @order="posters"
-        @activeOrder={{@order}}
-        @changeSort={{@changeSort}}
-        @ascending={{@ascending}}
-        @name="posters"
-        @screenreaderOnly={{true}}
-        aria-label={{i18n "category.sort_options.posters"}}
-      />
-    {{/if}}
-
-    <TopicListHeaderColumn
-      @sortable={{@sortable}}
-      @number="true"
-      @order="posts"
-      @activeOrder={{@order}}
-      @changeSort={{@changeSort}}
-      @ascending={{@ascending}}
-      @name="replies"
-    />
-
-    {{#if @showLikes}}
-      <TopicListHeaderColumn
-        @sortable={{@sortable}}
-        @number="true"
-        @order="likes"
-        @activeOrder={{@order}}
-        @changeSort={{@changeSort}}
-        @ascending={{@ascending}}
-        @name="likes"
-      />
-    {{/if}}
-
-    {{#if @showOpLikes}}
-      <TopicListHeaderColumn
-        @sortable={{@sortable}}
-        @number="true"
-        @order="op_likes"
-        @activeOrder={{@order}}
-        @changeSort={{@changeSort}}
-        @ascending={{@ascending}}
-        @name="likes"
-      />
-    {{/if}}
-
-    <TopicListHeaderColumn
-      @sortable={{@sortable}}
-      @number="true"
-      @order="views"
-      @activeOrder={{@order}}
-      @changeSort={{@changeSort}}
-      @ascending={{@ascending}}
-      @name="views"
-    />
-
-    <TopicListHeaderColumn
-      @sortable={{@sortable}}
-      @number="true"
-      @order="activity"
-      @activeOrder={{@order}}
-      @changeSort={{@changeSort}}
-      @ascending={{@ascending}}
-      @name="activity"
-    />
-
-    <PluginOutlet @name="topic-list-header-after" />
-  </tr>
-</template>;
-
-export default TopicListHeader;

app/assets/javascripts/discourse/app/lib/bulk-select-helper.js

@@ -1,10 +1,10 @@
 import { tracked } from "@glimmer/tracking";
+import { action } from "@ember/object";
 import { getOwner, setOwner } from "@ember/owner";
 import { service } from "@ember/service";
 import { TrackedArray } from "@ember-compat/tracked-built-ins";
 import { NotificationLevels } from "discourse/lib/notification-levels";
 import Topic from "discourse/models/topic";
-import { bind } from "discourse-common/utils/decorators";
 
 export default class BulkSelectHelper {
   @service router;
@@ -15,6 +15,7 @@ export default class BulkSelectHelper {
   @tracked bulkSelectEnabled = false;
   @tracked autoAddTopicsToBulkSelect = false;
   @tracked autoAddBookmarksToBulkSelect = false;
+  @tracked lastCheckedElementId = null;
 
   selected = new TrackedArray();
 
@@ -24,6 +25,7 @@ export default class BulkSelectHelper {
 
   clear() {
     this.selected.length = 0;
+    this.lastCheckedElementId = null;
   }
 
   addTopics(topics) {
@@ -34,8 +36,9 @@ export default class BulkSelectHelper {
     return this.selected.mapBy("category_id").uniq();
   }
 
-  @bind
+  @action
-  toggleBulkSelect() {
+  toggleBulkSelect(event) {
+    event?.preventDefault();
     this.bulkSelectEnabled = !this.bulkSelectEnabled;
     this.clear();
   }

app/assets/javascripts/discourse/app/lib/dag.js

@@ -1,10 +1,7 @@
 import DAGMap from "dag-map";
+import { makeArray } from "discourse-common/lib/helpers";
 import { bind } from "discourse-common/utils/decorators";
 
-function ensureArray(val) {
-  return Array.isArray(val) ? val : [val];
-}
-
 export default class DAG {
   /**
    * Creates a new DAG instance from an iterable of entries.
@@ -75,10 +72,10 @@ export default class DAG {
    */
   #defaultPositionForKey(key) {
     const pos = { ...this.#defaultPosition };
-    if (ensureArray(pos.before).includes(key)) {
+    if (makeArray(pos.before).includes(key)) {
       delete pos.before;
     }
-    if (ensureArray(pos.after).includes(key)) {
+    if (makeArray(pos.after).includes(key)) {
       delete pos.after;
     }
     return pos;

app/assets/javascripts/discourse/app/lib/transformer/registry.js

@@ -15,4 +15,5 @@ export const VALUE_TRANSFORMERS = Object.freeze([
   "more-topics-tabs",
   "post-menu-buttons",
   "small-user-attrs",
+  "topic-list-columns",
 ]);