MOBILE-2655 course: Decrease WS calls to get course completion

src/addon/coursecompletion/providers/coursecompletion.ts

@@ -165,7 +165,19 @@ export class AddonCourseCompletionProvider {
         }
 
         return this.coursesProvider.getUserCourse(courseId, preferCache).then((course) => {
-            return !(course && typeof course.enablecompletion != 'undefined' && course.enablecompletion == 0);
+            if (course) {
+                if (typeof course.enablecompletion != 'undefined' && course.enablecompletion == 0) {
+                    // Completion not enabled for the course.
+                    return false;
+                }
+
+                if (typeof course.completionhascriteria != 'undefined' && course.completionhascriteria == 0) {
+                    // No criteria, cannot view completion.
+                    return false;
+                }
+            }
+
+            return true;
         });
     }
 
@@ -177,6 +189,28 @@ export class AddonCourseCompletionProvider {
      * @return {Promise<boolean>} Promise resolved with true if plugin is enabled, rejected or resolved with false otherwise.
      */
     isPluginViewEnabledForUser(courseId: number, userId?: number): Promise<boolean> {
+        // Check if user wants to view his own completion.
+        const currentUserId = this.sitesProvider.getCurrentSiteUserId();
+        let promise;
+
+        if (!userId || userId == currentUserId) {
+            // Viewing own completion. Get the course to check if it has completion criteria.
+            promise = this.coursesProvider.getUserCourse(courseId, true).then((course): any => {
+                // If the site is returning the completionhascriteria then the user can view his own completion.
+                // We already checked the value in isPluginViewEnabledForCourse.
+                if (course && typeof course.completionhascriteria != 'undefined') {
+                    return true;
+                }
+
+                return Promise.reject(null);
+            });
+        } else {
+            promise = Promise.reject(null);
+        }
+
+        return promise.catch(() => {
+            // User not viewing own completion or the site doesn't tell us if the course has criteria.
+            // The only way to know if completion can be viewed is to call the WS.
             // Disable emergency cache to be able to detect that the plugin has been disabled (WS will fail).
             const preSets: any = {
                 emergencyCache: 0
@@ -199,6 +233,7 @@ export class AddonCourseCompletionProvider {
                     });
                 }
             });
+        });
     }
 
     /**

src/core/courses/providers/helper.ts

@@ -133,8 +133,13 @@ export class CoreCoursesHelperProvider {
                 }
                 courses = slice > 0 ? courses.slice(0, slice) : courses;
 
-                // Fetch course completion status.
+                // Fetch course completion status if needed.
                 return Promise.all(courses.map((course) => {
+                    if (typeof course.completed != 'undefined') {
+                        // The WebService already returns the completed status, no need to fetch it.
+                        return Promise.resolve(course);
+                    }
+
                     if (typeof course.enablecompletion != 'undefined' && course.enablecompletion == 0) {
                         // Completion is disabled for this course, there is no need to fetch the completion status.
                         return Promise.resolve(course);