Development: Prevent IDE settings from being loaded multiple times on…

… the scores page

src/main/webapp/app/core/auth/account.service.ts

@@ -41,6 +41,7 @@ export class AccountService implements IAccountService {
     private websocketService = inject(JhiWebsocketService);
     private featureToggleService = inject(FeatureToggleService);
 
+    // cached value of the user to avoid unnecessary requests to the server
     private userIdentityValue?: User;
     private authenticated = false;
     private authenticationState = new BehaviorSubject<User | undefined>(undefined);

src/main/webapp/app/shared/components/code-button/code-button.component.ts

@@ -26,20 +26,13 @@ export class CodeButtonComponent implements OnInit, OnChanges {
     readonly FeatureToggle = FeatureToggle;
     readonly ProgrammingLanguage = ProgrammingLanguage;
 
-    @Input()
-    loading = false;
-    @Input()
-    useParticipationVcsAccessToken = false;
-    @Input()
-    smallButtons: boolean;
-    @Input()
-    repositoryUri?: string;
-    @Input()
-    routerLinkForRepositoryView?: string | (string | number)[];
-    @Input()
-    participations?: ProgrammingExerciseStudentParticipation[];
-    @Input()
-    exercise?: ProgrammingExercise;
+    @Input() loading = false;
+    @Input() useParticipationVcsAccessToken = false;
+    @Input() smallButtons: boolean;
+    @Input() repositoryUri?: string;
+    @Input() routerLinkForRepositoryView?: string | (string | number)[];
+    @Input() participations?: ProgrammingExerciseStudentParticipation[];
+    @Input() exercise?: ProgrammingExercise;
 
     useSsh = false;
     useToken = false;
@@ -133,7 +126,7 @@ export class CodeButtonComponent implements OnInit, OnChanges {
             this.sshKeyMissingTip = this.formatTip('artemisApp.exerciseActions.sshKeyTip', this.sshSettingsUrl);
         });
 
-        this.ideSettingsService.loadIdePreferences().subscribe((programmingLanguageToIde) => {
+        this.ideSettingsService.loadIdePreferences().then((programmingLanguageToIde) => {
             if (programmingLanguageToIde.size) {
                 this.programmingLanguageToIde = programmingLanguageToIde;
             }

src/main/webapp/app/shared/user-settings/ide-preferences/ide-settings.component.ts

@@ -29,7 +29,7 @@ export class IdeSettingsComponent implements OnInit {
             this.PREDEFINED_IDE = predefinedIde;
         });
 
-        this.ideSettingsService.loadIdePreferences().subscribe((programmingLanguageToIdeMap) => {
+        this.ideSettingsService.loadIdePreferences(true).then((programmingLanguageToIdeMap) => {
             if (!programmingLanguageToIdeMap.has(ProgrammingLanguage.EMPTY)) {
                 programmingLanguageToIdeMap.set(ProgrammingLanguage.EMPTY, this.PREDEFINED_IDE[0]);
             }

src/main/webapp/app/shared/user-settings/ide-preferences/ide-settings.service.ts

@@ -1,14 +1,16 @@
 import { Injectable } from '@angular/core';
 import { map } from 'rxjs/operators';
-import { Observable } from 'rxjs';
+import { Observable, lastValueFrom } from 'rxjs';
 import { HttpClient, HttpParams, HttpResponse } from '@angular/common/http';
 import { Ide, IdeMappingDTO } from 'app/shared/user-settings/ide-preferences/ide.model';
 import { ProgrammingLanguage } from 'app/entities/programming/programming-exercise.model';
 
 @Injectable({ providedIn: 'root' })
 export class IdeSettingsService {
-    public ideSettingsUrl = 'api/ide-settings';
-    error?: string;
+    public readonly ideSettingsUrl = 'api/ide-settings';
+
+    // cached value of the ide preferences to avoid unnecessary requests to the server
+    private idePreferences?: Map<ProgrammingLanguage, Ide>;
 
     constructor(private http: HttpClient) {}
 
@@ -20,12 +22,45 @@ export class IdeSettingsService {
         return this.http.get<Ide[]>(this.ideSettingsUrl + '/predefined');
     }
 
+    private ongoingRequest: Promise<Map<ProgrammingLanguage, Ide>> | undefined = undefined;
+    private cacheTimestamp: number | undefined = undefined; // To store the timestamp when the preferences were loaded
+    private readonly cacheDuration = 60 * 1000; // 1 minute in milliseconds
+
     /**
      * GET call to the server to receive the stored ide preferences of the current user
+     * Prevent concurrent requests by caching the ongoing request and the timestamp when the preferences were loaded
+     * Load the settings again after 1min in case they have changed
+     * @param force if true, the cache will be ignored and a new request will be made
      * @return the saved ide preference which were found in the database or error
      */
-    public loadIdePreferences(): Observable<Map<ProgrammingLanguage, Ide>> {
-        return this.http.get<IdeMappingDTO[]>(this.ideSettingsUrl).pipe(map((data) => new Map<ProgrammingLanguage, Ide>(data.map((x) => [x.programmingLanguage, x.ide]))));
+    public loadIdePreferences(force?: boolean): Promise<Map<ProgrammingLanguage, Ide>> {
+        const currentTime = new Date().getTime();
+
+        // If preferences are already loaded and the cache is valid, return them immediately
+        if (this.idePreferences && !force && this.cacheTimestamp && currentTime - this.cacheTimestamp < this.cacheDuration) {
+            return Promise.resolve(this.idePreferences);
+        }
+
+        // If there's already an ongoing request, return that promise to prevent multiple calls
+        if (this.ongoingRequest) {
+            return this.ongoingRequest;
+        }
+
+        // Make the REST call and cache the ongoing request
+        this.ongoingRequest = lastValueFrom(
+            this.http.get<IdeMappingDTO[]>(this.ideSettingsUrl).pipe(
+                map((data) => {
+                    this.idePreferences = new Map<ProgrammingLanguage, Ide>(data.map((x) => [x.programmingLanguage, x.ide]));
+                    this.cacheTimestamp = new Date().getTime(); // Update the timestamp when the data is cached
+                    return this.idePreferences;
+                }),
+            ),
+        ).finally(() => {
+            // Clear the ongoingRequest once the promise resolves
+            this.ongoingRequest = undefined;
+        });
+
+        return this.ongoingRequest;
     }
 
     /**

src/test/javascript/spec/component/settings/ide/ide-settings.component.spec.ts

@@ -1,4 +1,4 @@
-import { ComponentFixture, TestBed } from '@angular/core/testing';
+import { ComponentFixture, TestBed, fakeAsync, tick } from '@angular/core/testing';
 import { CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
 import { of } from 'rxjs';
 import { IdeSettingsComponent } from 'app/shared/user-settings/ide-preferences/ide-settings.component';
@@ -34,27 +34,33 @@ describe('IdeSettingsComponent', () => {
         jest.resetAllMocks();
     });
 
-    it('should load predefined IDEs and IDE preferences on init', () => {
+    it('should load predefined IDEs and IDE preferences on init', fakeAsync(() => {
         const predefinedIdes = [
             { name: 'VS Code', deepLink: 'vscode://vscode.git/clone?url={cloneUrl}' },
             { name: 'IntelliJ', deepLink: 'jetbrains://idea/checkout/git?idea.required.plugins.id=Git4Idea&checkout.repo={cloneUrl}' },
         ];
         const idePreferences = new Map([[ProgrammingLanguage.JAVA, predefinedIdes[0]]]);
+        const loadedIdePreferences = new Map([
+            [ProgrammingLanguage.JAVA, predefinedIdes[0]],
+            [ProgrammingLanguage.EMPTY, predefinedIdes[0]],
+        ]);
 
         mockIdeSettingsService.loadPredefinedIdes.mockReturnValue(of(predefinedIdes));
-        mockIdeSettingsService.loadIdePreferences.mockReturnValue(of(idePreferences));
+        mockIdeSettingsService.loadIdePreferences.mockReturnValue(Promise.resolve(idePreferences));
 
         component.ngOnInit();
 
+        tick();
+
         expect(mockIdeSettingsService.loadPredefinedIdes).toHaveBeenCalledOnce();
         expect(mockIdeSettingsService.loadIdePreferences).toHaveBeenCalledOnce();
         expect(component.PREDEFINED_IDE).toEqual(predefinedIdes);
-        expect(component.programmingLanguageToIde()).toEqual(idePreferences);
+        expect(component.programmingLanguageToIde()).toEqual(loadedIdePreferences);
         expect(component.assignedProgrammingLanguages).toEqual([ProgrammingLanguage.JAVA]);
         expect(component.remainingProgrammingLanguages).toEqual(
             Object.values(ProgrammingLanguage).filter((x) => x !== ProgrammingLanguage.JAVA && x !== ProgrammingLanguage.EMPTY),
         );
-    });
+    }));
 
     it('should add a programming language and update the lists', () => {
         const programmingLanguage = ProgrammingLanguage.JAVA;

src/test/javascript/spec/service/settings/ide-settings.service.spec.ts

@@ -1,4 +1,4 @@
-import { TestBed } from '@angular/core/testing';
+import { TestBed, fakeAsync, tick } from '@angular/core/testing';
 import { HttpTestingController, provideHttpClientTesting } from '@angular/common/http/testing';
 import { IdeSettingsService } from 'app/shared/user-settings/ide-preferences/ide-settings.service';
 import { Ide, IdeMappingDTO } from 'app/shared/user-settings/ide-preferences/ide.model';
@@ -34,20 +34,22 @@ describe('IdeSettingsService', () => {
         req.flush(mockIdes);
     });
 
-    it('should load IDE preferences', () => {
+    it('should load IDE preferences', fakeAsync(() => {
         const mockIdeMappingDTO: IdeMappingDTO[] = [
             { programmingLanguage: ProgrammingLanguage.JAVA, ide: { name: 'VS Code', deepLink: 'vscode://vscode.git/clone?url={cloneUrl}' } },
         ];
         const expectedMap = new Map<ProgrammingLanguage, Ide>([[ProgrammingLanguage.JAVA, { name: 'VS Code', deepLink: 'vscode://vscode.git/clone?url={cloneUrl}' }]]);
 
-        service.loadIdePreferences().subscribe((ideMap) => {
+        service.loadIdePreferences().then((ideMap) => {
             expect(ideMap).toEqual(expectedMap);
         });
 
+        tick();
+
         const req = httpMock.expectOne(service.ideSettingsUrl);
         expect(req.request.method).toBe('GET');
         req.flush(mockIdeMappingDTO);
-    });
+    }));
 
     it('should save IDE preference', () => {
         const programmingLanguage = ProgrammingLanguage.JAVA;