MOBILE-3890 course: Add cache for modules

Author: crazyserver

src/core/features/course/services/course-force-language.ts

@@ -37,10 +37,14 @@ export class CoreCourseForceLanguageService {
     protected lastNavigationCheck: {
         courseId: number;
         courseLang: string | undefined;
+        cmId: number;
+        cmLang: string | undefined;
         timestamp: number;
     }= {
         courseId: 0,
         courseLang: undefined,
+        cmId: 0,
+        cmLang: undefined,
         timestamp: 0,
     };
 
@@ -81,37 +85,46 @@ export class CoreCourseForceLanguageService {
     protected async getForcedLanguageFromRoute(origin: string): 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 modLang = await this.getModuleForcedLangFromRoute(courseId);
-        if (modLang) {
-            return modLang;
+        if (origin === 'module') {
+            const modLang = await this.getModuleForcedLangFromRoute(courseId);
+            if (modLang) {
+                return modLang;
+            }
+        } else {
+            this.lastNavigationCheck.cmId = 0;
+            this.lastNavigationCheck.cmLang = undefined;
         }
 
+        let lang: string | undefined = undefined;
         if (this.lastNavigationCheck.courseId === courseId) {
-            return this.lastNavigationCheck.courseLang;
-        }
-        this.lastNavigationCheck.courseId = courseId;
-
-        if (course?.lang !== undefined) {
-            this.lastNavigationCheck.courseLang = course.lang;
+            console.error('Using cached course language', this.lastNavigationCheck.courseLang);
+
+            lang = this.lastNavigationCheck.courseLang;
+        } else if (course?.lang !== undefined) {
+                lang = course.lang;
+        } else {
+            course = await CorePromiseUtils.ignoreErrors(
+                CoreCourses.getCourseByField('id', courseId, { readingStrategy: CoreSitesReadingStrategy.PREFER_CACHE }),
+            );
 
-            return course.lang;
+            lang = course?.lang;
         }
 
-        course = await CorePromiseUtils.ignoreErrors(
-            CoreCourses.getCourseByField('id', courseId, { readingStrategy: CoreSitesReadingStrategy.PREFER_CACHE }),
-        );
-
-        this.lastNavigationCheck.courseLang = course?.lang;
+        this.lastNavigationCheck.courseId = courseId;
+        this.lastNavigationCheck.courseLang = lang;
 
-        return course?.lang;
+        return lang;
     }
 
     /**
@@ -122,21 +135,30 @@ export class CoreCourseForceLanguageService {
      */
     protected async getModuleForcedLangFromRoute(courseId: number): Promise<string | undefined> {
         const cmId = CoreNavigator.getRouteNumberParam('cmId');
+        let lang: string | undefined = undefined;
         if (cmId) {
-            // 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),
-            );
-
-            if (module) {
-                const lang = await CorePromiseUtils.ignoreErrors(
-                    CoreCourseModuleDelegate.getModuleForcedLang(module),
+            if (this.lastNavigationCheck.cmId === cmId) {
+                console.error('Using cached cm language', this.lastNavigationCheck.cmLang);
+
+                lang = this.lastNavigationCheck.cmLang;
+            } else {
+                // 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),
                 );
-                if (lang) {
-                    return lang;
+
+                if (module) {
+                    lang = await CorePromiseUtils.ignoreErrors(
+                        CoreCourseModuleDelegate.getModuleForcedLang(module),
+                    );
                 }
             }
         }
+
+        this.lastNavigationCheck.cmId = cmId ?? 0;
+        this.lastNavigationCheck.cmLang = lang;
+
+        return lang;
     }
 
 }