constructor(mainMenuDelegate: CoreMainMenuDelegate, gradesMenuHandler: CoreGradesMainMenuHandler,
            courseOptionHandler: CoreGradesCourseOptionHandler, courseOptionsDelegate: CoreCourseOptionsDelegate,
            contentLinksDelegate: CoreContentLinksDelegate, userLinkHandler: CoreGradesUserLinkHandler,
            overviewLinkHandler: CoreGradesOverviewLinkHandler, userHandler: CoreGradesUserHandler,
            userDelegate: CoreUserDelegate, eventsProvider: CoreEventsProvider, sitesProvider: CoreSitesProvider) {

        // Register handlers.
        mainMenuDelegate.registerHandler(gradesMenuHandler);
        courseOptionsDelegate.registerHandler(courseOptionHandler);
        contentLinksDelegate.registerHandler(userLinkHandler);
        contentLinksDelegate.registerHandler(overviewLinkHandler);
        userDelegate.registerHandler(userHandler);

        // Clear user profile handler cache.
        eventsProvider.on(CoreUserProvider.PROFILE_REFRESHED, (data) => {
            userHandler.clearViewGradesCache(data.courseId, data.userId);
        }, sitesProvider.getCurrentSiteId());

        eventsProvider.on(CoreEventsProvider.LOGOUT, () => {
            userHandler.clearViewGradesCache();
        }, sitesProvider.getCurrentSiteId());
    }

    /**
     * Convenient helper to get the user profile image.
     *
     * @param  {number} userId User Id
     * @return {Promise<any>}  User profile Image URL or true if default icon.
     */
    getProfile(userId: number): Promise<any> {
        if (!userId || userId == this.sitesProvider.getCurrentSiteUserId()) {
            return Promise.resolve(false);
        }

        // Get the user profile to retrieve the user image.
        return this.userProvider.getProfile(userId, null, true).then((user) => {
            user.profileimageurl = user.profileimageurl || true;

            return user;
        });
    }

            messagesProvider.isMessagingEnabledForSite(notification.site).then(() => {
                sitesProvider.isFeatureDisabled('CoreMainMenuDelegate_AddonMessages', notification.site).then((disabled) => {
                    if (disabled) {
                        // Messages are disabled, stop.
                        return;
                    }

                    messagesProvider.invalidateDiscussionsCache(notification.site).finally(() => {
                        linkHelper.goInSite(undefined, 'AddonMessagesIndexPage', undefined, notification.site);
                    });
                });
            });

 /**
  * Load the right page.
  *
  * @return {Promise<any>} Promise resolved when done.
  */
 protected loadPage(): Promise<any> {
     if (this.sitesProvider.isLoggedIn()) {
         if (!this.loginHelper.isSiteLoggedOut()) {
             // User is logged in, go to site initial page.
             return this.loginHelper.goToSiteInitialPage();
         } else {
             // The site is marked as logged out. Logout and try again.
             return this.sitesProvider.logout().then(() => {
                 return this.loadPage();
             });
         }
     } else {
         return this.sitesProvider.hasSites().then((hasSites) => {
             if (hasSites) {
                 return this.navCtrl.setRoot('CoreLoginSitesPage');
             } else {
                 return this.loginHelper.goToAddSite(true);
             }
         });
     }
 }

    /**
     * Retrieve the entered data in the edit form.
     * We don't use ng-model because it doesn't detect changes done by JavaScript.
     *
     * @param  {any}     inputData    Array with the entered form values.
     * @param  {Array}   fields       Fields that defines every content in the entry.
     * @param  {number}  [dataId]     Database Id. If set, files will be uploaded and itemId set.
     * @param  {number}  entryId      Entry Id.
     * @param  {any}  entryContents   Original entry contents indexed by field id.
     * @param  {boolean} offline      True to prepare the data for an offline uploading, false otherwise.
     * @param  {string}  [siteId]     Site ID. If not defined, current site.
     * @return {Promise<any>}         That contains object with the answers.
     */
    getEditDataFromForm(inputData: any, fields: any, dataId: number, entryId: number, entryContents: any, offline: boolean = false,
            siteId?: string): Promise<any> {
        if (!inputData) {
            return Promise.resolve({});
        }

        siteId = siteId || this.sitesProvider.getCurrentSiteId();

        // Filter and translate fields to each field plugin.
        const edit = [],
            promises = [];
        fields.forEach((field) => {
            promises.push(Promise.resolve(this.fieldsDelegate.getFieldEditData(field, inputData, entryContents[field.id]))
                    .then((fieldData) => {
                if (fieldData) {
                    const proms = [];

                    fieldData.forEach((data) => {
                        let dataProm;

                        // Upload Files if asked.
                        if (dataId && data.files) {
                            dataProm = this.uploadOrStoreFiles(dataId, 0, entryId, data.fieldid, data.files, offline, siteId)
                                    .then((filesResult) => {
                                delete data.files;
                                data.value = filesResult;
                            });
                        } else {
                            dataProm = Promise.resolve();
                        }

                        proms.push(dataProm.then(() => {
                            if (data.value) {
                                data.value = JSON.stringify(data.value);
                            }
                            if (typeof data.subfield == 'undefined') {
                                data.subfield = '';
                            }

                            // WS wants values in Json format.
                            edit.push(data);
                        }));
                    });

                    return Promise.all(proms);
                }
            }));
        });

        return Promise.all(promises).then(() => {
            return edit;
        });
    }

        const notificationClicked = (notification: any): void => {
            sitesProvider.isFeatureDisabled('CoreMainMenuDelegate_AddonNotifications', notification.site).then((disabled) => {
                if (disabled) {
                    // Notifications are disabled, stop.
                    return;
                }

                notificationsProvider.invalidateNotificationsList().finally(() => {
                    linkHelper.goInSite(undefined, 'AddonNotificationsListPage', undefined, notification.site);
                });
            });
        };

    ngOnInit(): void {
        this.selectedSite = this.initialSite || this.sitesProvider.getCurrentSiteId();

        // Load the sites.
        this.sitesProvider.getSites().then((sites) => {
            const promises = [];

            sites.forEach((site: any) => {
                // Format the site name.
                promises.push(this.textUtils.formatText(site.siteName, true, true).catch(() => {
                    return site.siteName;
                }).then((formatted) => {
                    site.fullNameAndSiteName = this.translate.instant('core.fullnameandsitename',
                        { fullname: site.fullName, sitename: formatted });
                }));
            });

            return Promise.all(promises).then(() => {
                this.sites = sites;
            });
        });
    }

    /**
     * Tries to authenticate the user.
     *
     * @param {Event} e Event.
     */
    login(e: Event): void {
        e.preventDefault();
        e.stopPropagation();

        this.appProvider.closeKeyboard();

        // Get input data.
        const siteUrl = this.siteUrl,
            username = this.username,
            password = this.credForm.value.password;

        if (!password) {
            this.domUtils.showErrorModal('core.login.passwordrequired', true);

            return;
        }

        if (!this.appProvider.isOnline()) {
            this.domUtils.showErrorModal('core.networkerrormsg', true);

            return;
        }

        const modal = this.domUtils.showModalLoading();

        // Start the authentication process.
        this.sitesProvider.getUserToken(siteUrl, username, password).then((data) => {
            return this.sitesProvider.updateSiteToken(this.infoSiteUrl, username, data.token, data.privateToken).then(() => {
                // Update site info too because functions might have changed (e.g. unisntall local_mobile).
                return this.sitesProvider.updateSiteInfoByUrl(this.infoSiteUrl, username).then(() => {
                    // Reset fields so the data is not in the view anymore.
                    this.credForm.controls['password'].reset();

                    if (this.pageName) {
                        // Page defined, go to that page instead of site initial page.
                        return this.navCtrl.setRoot(this.pageName, this.pageParams);
                    } else {
                        return this.loginHelper.goToSiteInitialPage();
                    }
                }).catch((error) => {
                    // Error, go back to login page.
                    this.domUtils.showErrorModalDefault(error, 'core.login.errorupdatesite', true);
                    this.cancel();
                });
            });
        }).catch((error) => {
            this.loginHelper.treatUserTokenError(siteUrl, error, username, password);
        }).finally(() => {
            modal.dismiss();
        });
    }

            return this.sitesProvider.updateSiteToken(this.infoSiteUrl, username, data.token, data.privateToken).then(() => {
                // Update site info too because functions might have changed (e.g. unisntall local_mobile).
                return this.sitesProvider.updateSiteInfoByUrl(this.infoSiteUrl, username).then(() => {
                    // Reset fields so the data is not in the view anymore.
                    this.credForm.controls['password'].reset();

                    // Go to the site initial page.
                    return this.loginHelper.goToSiteInitialPage(this.navCtrl, this.pageName, this.pageParams);
                }).catch((error) => {
                    // Error, go back to login page.
                    this.domUtils.showErrorModalDefault(error, 'core.login.errorupdatesite', true);
                    this.cancel();
                });
            });

    /**
     * Component being initialized.
     */
    ngOnInit(): void {
        super.ngOnInit();

        this.hasOffline = false;
        this.syncIcon = 'spinner';
        this.siteId = this.sitesProvider.getCurrentSiteId();
        this.moduleName = this.courseProvider.translateModuleName(this.moduleName);

        if (this.syncEventName) {
            // Refresh data if this discussion is synchronized automatically.
            this.syncObserver = this.eventsProvider.on(this.syncEventName, (data) => {
                this.autoSyncEventReceived(data);
            }, this.siteId);
        }
    }