MOBILE-3890 course: Add cache for modules

Author: crazyserver

src/core/features/course/services/course.ts

@@ -140,10 +140,14 @@ export class CoreCourseProvider {
     protected lastNavigationCheck: {
         courseId: number;
         courseLang: string | undefined;
+        cmId: number;
+        cmLang: string | undefined;
         timestamp: number;
     }= {
         courseId: 0,
         courseLang: undefined,
+        cmId: 0,
+        cmLang: undefined,
         timestamp: 0,
     };
 
@@ -201,16 +205,27 @@ export class CoreCourseProvider {
     protected async getCourseLanguageFromRoute(): Promise<string | undefined> {
         let course = CoreNavigator.getRouteParam<CoreCourseSearchedData>('course');
         const courseId = course?.id ?? CoreNavigator.getRouteNumberParam('courseId');
+
         if (!courseId) {
             // Not in a course/module, empty the cache and return.
             this.lastNavigationCheck.courseId = 0;
             this.lastNavigationCheck.courseLang = undefined;
+            this.lastNavigationCheck.cmId = 0;
+            this.lastNavigationCheck.cmLang = undefined;
 
             return;
         }
 
         const cmId = CoreNavigator.getRouteNumberParam('cmId');
         if (cmId) {
+            if (this.lastNavigationCheck.cmId === cmId) {
+                console.error('Using cached cm language', this.lastNavigationCheck.cmLang);
+
+                return this.lastNavigationCheck.cmLang;
+            }
+            this.lastNavigationCheck.cmId = cmId;
+            this.lastNavigationCheck.cmLang = undefined;
+
             // TODO: In the future this should directly return the module language instead of checking the delegate.
             const module = await CorePromiseUtils.ignoreErrors(
                 CoreCourse.getModule(cmId, courseId, undefined, true),
@@ -221,12 +236,19 @@ export class CoreCourseProvider {
                     CoreCourseModuleDelegate.getModuleForcedLang(module),
                 );
                 if (lang) {
+                    this.lastNavigationCheck.cmLang = lang;
+
                     return lang;
                 }
             }
+        } else {
+            this.lastNavigationCheck.cmId = 0;
+            this.lastNavigationCheck.cmLang = undefined;
         }
 
         if (this.lastNavigationCheck.courseId === courseId) {
+            console.error('Using cached course language', this.lastNavigationCheck.courseLang);
+
             return this.lastNavigationCheck.courseLang;
         }
         this.lastNavigationCheck.courseId = courseId;