refactor(materials): streamline loading of default material folder

app/controllers/course/material/materials_controller.rb

@@ -1,6 +1,15 @@
 # frozen_string_literal: true
 class Course::Material::MaterialsController < Course::Material::Controller
-  load_and_authorize_resource :material, through: :folder, class: 'Course::Material'
+  load_and_authorize_resource :material, through: :folder, class: 'Course::Material', except: :load_default
+
+  def load_default
+    @folder = Course::Material::Folder.where(course_id: current_course.id, parent_id: nil).order(:created_at).first
+    if @folder
+      render json: @folder, status: :ok
+    else
+      render json: { error: 'No folders available' }, status: :not_found
+    end
+  end
 
   def show
     authorize!(:read_owner, @material.folder)

client/app/api/course/Materials.ts

@@ -3,6 +3,8 @@ import { FileListData } from 'types/course/material/files';
 
 import { APIResponse } from 'api/types';
 
+import {FolderMiniEntity} from '../../types/course/material/folders';
+
 import BaseCourseAPI from './Base';
 
 const getShouldDownloadFromContentDisposition = (
@@ -15,8 +17,12 @@ const getShouldDownloadFromContentDisposition = (
 };
 
 export default class MaterialsAPI extends BaseCourseAPI {
+  get #materialPrefix(): string {
+    return `/courses/${this.courseId}/materials`;
+  }
+
   get #urlPrefix(): string {
-    return `/courses/${this.courseId}/materials/folders`;
+    return `${this.#materialPrefix}/folders`;
   }
 
   fetch(folderId: number, materialId: number): APIResponse<FileListData> {
@@ -25,6 +31,10 @@ export default class MaterialsAPI extends BaseCourseAPI {
     );
   }
 
+  fetchDefault(): APIResponse<FolderMiniEntity> {
+    return this.client.get(`${this.#materialPrefix}`);
+  }
+
   /**
    * Attempts to download the file at the given `url` as a `Blob` and returns
    * its URL and disposition. Remember to `revoke` the URL when no longer needed.

client/app/bundles/course/material/folders/handles.ts

@@ -3,52 +3,35 @@ import { getIdFromUnknown } from 'utilities';
 import CourseAPI from 'api/course';
 import { CrumbPath, DataHandle } from 'lib/hooks/router/dynamicNest';
 
-const extractMaterial = (
-  sidebar: { label: string; key: string; path: string }[],
-): { label: string; key: string; path: string } | undefined =>
-  sidebar.find((item) => item.key === 'materials');
-
-export const loadDefaultMaterial = async (
-  courseId: number,
-): Promise<{
-  label: string;
-  key: string;
-  path: string;
-} | null> => {
+export const loadDefaultMaterialId = async (): Promise<number> => {
   const {
-    data: { sidebar },
-  } = await CourseAPI.courses.fetchLayout(courseId);
-  return sidebar ? extractMaterial(sidebar) || null : null;
+    data: { id },
+  } = await CourseAPI.materials.fetchDefault();
+  return id;
 };
 
 const getFolderTitle = async (
   courseId: string,
   folderId: number,
 ): Promise<CrumbPath> => {
   const courseUrl = `/courses/${courseId}`;
+  let data;
   try {
-    const { data } = await CourseAPI.folders.fetch(folderId);
-    const workbinUrl = `${courseUrl}/materials/folders/${data.breadcrumbs[0].id}`;
-
-    return {
-      activePath: workbinUrl,
-      content: data.breadcrumbs.map((crumb) => ({
-        title: crumb.name,
-        url: `materials/folders/${crumb.id}`,
-      })),
-    };
+    ({ data } = await CourseAPI.folders.fetch(folderId));
   } catch (error) {
-    const defaultMaterial = await loadDefaultMaterial(+courseId);
-    const title = defaultMaterial ? defaultMaterial.label : 'Materials';
-
-    return {
-      activePath: courseUrl,
-      content: {
-        title,
-        url: courseUrl,
-      },
-    };
+    const defaultMaterialId = await loadDefaultMaterialId();
+    ({ data } = await CourseAPI.folders.fetch(defaultMaterialId));
   }
+
+  const workbinUrl = `${courseUrl}/materials/folders/${data.breadcrumbs[0].id}`;
+
+  return {
+    activePath: workbinUrl,
+    content: data.breadcrumbs.map((crumb) => ({
+      title: crumb.name,
+      url: `materials/folders/${crumb.id}`,
+    })),
+  };
 };
 
 /**

client/app/bundles/course/material/folders/pages/ErrorRetrievingFolderPage.tsx

@@ -3,7 +3,7 @@ import { defineMessages } from 'react-intl';
 import { useParams } from 'react-router-dom';
 import { Cancel, FolderOutlined } from '@mui/icons-material';
 
-import { loadDefaultMaterial } from 'course/material/folders/handles';
+import { loadDefaultMaterialId } from 'course/material/folders/handles';
 import Link from 'lib/components/core/Link';
 import useTranslation from 'lib/hooks/useTranslation';
 
@@ -40,10 +40,10 @@ const useWorkbinURL = (courseId: string | undefined): string => {
 
   useEffect(() => {
     if (courseId) {
-      loadDefaultMaterial(+courseId).then((materialsItem) => {
-        if (materialsItem?.path) {
-          setWorkbinURL(materialsItem.path);
-        }
+      loadDefaultMaterialId().then((defaultMaterialId) => {
+        setWorkbinURL(
+          `/courses/${courseId}/materials/folders/${defaultMaterialId}`,
+        );
       });
     }
   }, [courseId]);

config/routes.rb

@@ -410,6 +410,7 @@
       end
 
       namespace :material, path: 'materials' do
+        get '/', to: 'materials#load_default'
         resources :folders, except: [:index, :new, :create] do
           post 'create/subfolder', on: :member, as: 'create_subfolder', action: 'create_subfolder'
           put 'upload_materials', on: :member