MOBILE-2992 forum: Sort discussions

scripts/langindex.json

@@ -483,6 +483,12 @@
   "addon.mod_forum.addanewtopic": "forum",
   "addon.mod_forum.addtofavourites": "forum",
   "addon.mod_forum.advanced": "forum",
+  "addon.mod_forum.bycreateddesc": "local_moodlemobileapp",
+  "addon.mod_forum.bycreatedasc": "local_moodlemobileapp",
+  "addon.mod_forum.bylastpostdesc": "local_moodlemobileapp",
+  "addon.mod_forum.bylastpostasc": "local_moodlemobileapp",
+  "addon.mod_forum.byrepliesdesc": "local_moodlemobileapp",
+  "addon.mod_forum.byrepliesasc": "local_moodlemobileapp",
   "addon.mod_forum.cannotadddiscussion": "forum",
   "addon.mod_forum.cannotadddiscussionall": "forum",
   "addon.mod_forum.cannotcreatediscussion": "forum",
@@ -1734,6 +1740,7 @@
   "core.sizemb": "moodle",
   "core.sizetb": "local_moodlemobileapp",
   "core.sorry": "local_moodlemobileapp",
+  "core.sort": "moodle",
   "core.sortby": "moodle",
   "core.start": "grouptool",
   "core.strftimedate": "langconfig",

src/addon/mod/forum/components/index/addon-mod-forum-index.html

@@ -8,6 +8,7 @@
         <core-context-menu-item *ngIf="loaded && (hasOffline || hasOfflineRatings) && isOnline"  [priority]="600" [content]="'core.settings.synchronizenow' | translate" (action)="doRefresh(null, $event, true)" [iconAction]="syncIcon" [closeOnClick]="false"></core-context-menu-item>
         <core-context-menu-item *ngIf="prefetchStatusIcon" [priority]="500" [content]="prefetchText" (action)="prefetch()" [iconAction]="prefetchStatusIcon" [closeOnClick]="false"></core-context-menu-item>
         <core-context-menu-item *ngIf="size" [priority]="400" [content]="size" [iconDescription]="'cube'" (action)="removeFiles()" [iconAction]="'trash'"></core-context-menu-item>
+        <core-context-menu-item *ngIf="sortingAvailable" [priority]="300" [content]="'core.sort' | translate" (action)="showSortOrderSelector($event)" iconAction="fa-sort"></core-context-menu-item>
     </core-context-menu>
 </core-navbar-buttons>
 
@@ -30,6 +31,21 @@
                 <ion-icon name="information-circle"></ion-icon> {{ availabilityMessage }}
             </ion-card>
 
+            <core-empty-box *ngIf="forum && discussions.length == 0" icon="chatbubbles" [message]="'addon.mod_forum.forumnodiscussionsyet' | translate" class="core-empty-box-clickable">
+                <div padding *ngIf="forum.cancreatediscussions">
+                    <button ion-button block (click)="openNewDiscussion()">
+                        {{ 'addon.mod_forum.addanewdiscussion' | translate }}
+                    </button>
+                </div>
+            </core-empty-box>
+
+            <div text-wrap *ngIf="sortingAvailable && selectedSortOrder" ion-row padding-horizontal padding-top margin-bottom>
+                <button *ngIf="sortingAvailable" ion-button padding-horizontal icon-end ion-col (click)="showSortOrderSelector($event)" color="light" class="core-button-select button-no-uppercase" [attr.aria-label]="('core.sort' | translate)" aria-haspopup="true" [attr.aria-expanded]="sortOrderSelectorExpanded" aria-controls="addon-mod-forum-sort-order-selector" id="addon-mod-forum-sort-order-button">
+                    <span class="core-section-selector-text">{{ selectedSortOrder.label | translate }}</span>
+                    <ion-icon name="arrow-dropdown" ios="md-arrow-dropdown"></ion-icon>
+                </button>
+            </div>
+
             <ng-container *ngIf="forum && discussions.length > 0">
                 <ion-card *ngFor="let discussion of offlineDiscussions" (click)="openNewDiscussion(discussion.timecreated)" [class.addon-forum-discussion-selected]="discussion.timecreated == -selectedDiscussion">
                     <ion-item text-wrap>
@@ -86,14 +102,6 @@
                 </ion-card>
             </ng-container>
 
-            <core-empty-box *ngIf="forum && discussions.length == 0" icon="chatbubbles" [message]="'addon.mod_forum.forumnodiscussionsyet' | translate" class="core-empty-box-clickable">
-                <div padding *ngIf="forum.cancreatediscussions">
-                    <button ion-button block (click)="openNewDiscussion()">
-                        {{ 'addon.mod_forum.addanewdiscussion' | translate }}
-                    </button>
-                </div>
-            </core-empty-box>
-
             <core-infinite-loading [enabled]="canLoadMore" (action)="fetchMoreDiscussions($event)" [error]="loadMoreError"></core-infinite-loading>
         </core-loading>
 

src/addon/mod/forum/components/index/index.scss

@@ -2,7 +2,15 @@ ion-app.app-root addon-mod-forum-index {
     .addon-forum-discussion-selected {
         border-top: 5px solid $core-splitview-selected;
     }
+
     .addon-forum-star {
         color: $core-star-color;
     }
+
+    button.core-button-select .core-section-selector-text {
+        overflow: hidden;
+        text-overflow: ellipsis;
+        line-height: 2em;
+        white-space: nowrap;
+    }
 }

src/addon/mod/forum/components/index/index.ts

@@ -13,7 +13,7 @@
 // limitations under the License.
 
 import { Component, Optional, Injector, ViewChild } from '@angular/core';
-import { Content, NavController } from 'ionic-angular';
+import { Content, ModalController, NavController } from 'ionic-angular';
 import { CoreSplitViewComponent } from '@components/split-view/split-view';
 import { CoreCourseModuleMainActivityComponent } from '@core/course/classes/main-activity-component';
 import { CoreCourseModulePrefetchDelegate } from '@core/course/providers/module-prefetch-delegate';
@@ -52,6 +52,11 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
     addDiscussionText = this.translate.instant('addon.mod_forum.addanewdiscussion');
     availabilityMessage: string;
 
+    sortingAvailable: boolean;
+    sortOrders = [];
+    selectedSortOrder = null;
+    sortOrderSelectorExpanded = false;
+
     protected syncEventName = AddonModForumSyncProvider.AUTO_SYNCED;
     protected page = 0;
     protected trackPosts = false;
@@ -69,6 +74,7 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
     constructor(injector: Injector,
             @Optional() protected content: Content,
             protected navCtrl: NavController,
+            protected modalCtrl: ModalController,
             protected groupsProvider: CoreGroupsProvider,
             protected userProvider: CoreUserProvider,
             protected forumProvider: AddonModForumProvider,
@@ -79,6 +85,9 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
             protected prefetchHandler: AddonModForumPrefetchHandler,
             protected ratingOffline: CoreRatingOfflineProvider) {
         super(injector);
+
+        this.sortingAvailable = this.forumProvider.isDiscussionListSortingAvailable();
+        this.sortOrders = this.forumProvider.getAvailableSortOrders();
     }
 
     /**
@@ -162,7 +171,9 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
     protected fetchContent(refresh: boolean = false, sync: boolean = false, showErrors: boolean = false): Promise<any> {
         this.loadMoreError = false;
 
-        return this.forumProvider.getForum(this.courseId, this.module.id).then((forum) => {
+        const promises = [];
+
+        promises.push(this.forumProvider.getForum(this.courseId, this.module.id).then((forum) => {
             this.forum = forum;
 
             this.description = forum.intro || this.description;
@@ -212,7 +223,11 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
                     this.canAddDiscussion = this.forum.cancreatediscussions && !cutoffDateReached;
                 }),
             ]);
-        }).then(() => {
+        }));
+
+        promises.push(this.fetchSortOrderPreference());
+
+        return Promise.all(promises).then(() => {
             return Promise.all([
                 this.fetchOfflineDiscussion(),
                 this.fetchDiscussions(refresh),
@@ -291,7 +306,7 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
             this.page = 0;
         }
 
-        return this.forumProvider.getDiscussions(this.forum.id, this.page).then((response) => {
+        return this.forumProvider.getDiscussions(this.forum.id, this.selectedSortOrder.value, this.page).then((response) => {
             let promise;
             if (this.usesGroups) {
                 promise = this.forumProvider.formatDiscussionsGroups(this.forum.cmid, response.discussions);
@@ -366,6 +381,27 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
         });
     }
 
+    /**
+     * Convenience function to fetch the sort order preference.
+     *
+     * @return {Promise<any>} Promise resolved when done.
+     */
+    protected fetchSortOrderPreference(): Promise<any> {
+        let promise;
+        if (this.sortingAvailable) {
+            promise = this.userProvider.getUserPreference(AddonModForumProvider.PREFERENCE_SORTORDER).then((value) => {
+                return value ? parseInt(value, 10) : null;
+            });
+        } else {
+            // Use default.
+            promise = Promise.resolve(null);
+        }
+
+        return promise.then((value) => {
+           this.selectedSortOrder = this.sortOrders.find((sortOrder) => sortOrder.value === value) || this.sortOrders[0];
+        });
+    }
+
     /**
      * Perform the invalidate content function.
      *
@@ -382,6 +418,10 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
             promises.push(this.forumProvider.invalidateAccessInformation(this.forum.id));
         }
 
+        if (this.sortingAvailable) {
+            promises.push(this.userProvider.invalidateUserPreference(AddonModForumProvider.PREFERENCE_SORTORDER));
+        }
+
         return Promise.all(promises);
     }
 
@@ -484,6 +524,37 @@ export class AddonModForumIndexComponent extends CoreCourseModuleMainActivityCom
         this.selectedDiscussion = 0;
     }
 
+    /**
+     * Display the sort order selector modal.
+     *
+     * @param {MouseEvent} event Event.
+     */
+    showSortOrderSelector(event: MouseEvent): void {
+        if (!this.sortingAvailable) {
+            return;
+        }
+
+        const params = { sortOrders: this.sortOrders, selected: this.selectedSortOrder.value };
+        const modal = this.modalCtrl.create('AddonModForumSortOrderSelectorPage', params);
+        modal.onDidDismiss((sortOrder) => {
+            this.sortOrderSelectorExpanded = false;
+
+            if (sortOrder && sortOrder.value != this.selectedSortOrder.value) {
+                this.selectedSortOrder = sortOrder;
+                this.page = 0;
+                this.userProvider.setUserPreference(AddonModForumProvider.PREFERENCE_SORTORDER, sortOrder.value.toFixed(0))
+                        .then(() => {
+                    this.showLoadingAndFetch();
+                }).catch((error) => {
+                    this.domUtils.showErrorModalDefault(error, 'Error updating preference.');
+                });
+            }
+        });
+
+        modal.present({ev: event});
+        this.sortOrderSelectorExpanded = true;
+    }
+
     /**
      * Component being destroyed.
      */

src/addon/mod/forum/lang/en.json

@@ -4,6 +4,12 @@
     "addanewtopic": "Add a new topic",
     "addtofavourites": "Star this discussion",
     "advanced": "Advanced",
+    "bycreateddesc": "By creation date in descending order",
+    "bycreatedasc": "By creation date in ascending order",
+    "bylastpostdesc": "By last post in descending order",
+    "bylastpostasc": "By last post in ascending order",
+    "byrepliesdesc": "By number of replies in descending order",
+    "byrepliesasc": "By number of replies in ascending order",
     "cannotadddiscussion": "Adding discussions to this forum requires group membership.",
     "cannotadddiscussionall": "You do not have permission to add a new discussion topic for all participants.",
     "cannotcreatediscussion": "Could not create new discussion",

src/addon/mod/forum/pages/sort-order-selector/sort-order-selector.html

@@ -0,0 +1,19 @@
+<ion-header>
+    <ion-navbar core-back-button>
+        <ion-title>{{ 'core.sort' | translate }}</ion-title>
+        <ion-buttons end>
+            <button ion-button icon-only (click)="closeModal()" [attr.aria-label]="'core.close' | translate">
+                <ion-icon name="close"></ion-icon>
+            </button>
+        </ion-buttons>
+    </ion-navbar>
+</ion-header>
+<ion-content>
+    <ion-list id="addon-mod-forum-sort-selector" role="menu" aria-labelledby="addon-mod-forum-sort-order-button">
+        <ng-container *ngFor="let sortOrder of sortOrders">
+            <a ion-item text-wrap (click)="selectSortOrder(sortOrder)" [class.core-primary-selected-item]="selected == sortOrder.value" detail-none role="menuitem" [attr.aria-label]="sortOrder.label | translate">
+                <h2><core-format-text [text]="sortOrder.label | translate"></core-format-text></h2>
+            </a>
+        </ng-container>
+    </ion-list>
+</ion-content>

src/addon/mod/forum/pages/sort-order-selector/sort-order-selector.module.ts

@@ -0,0 +1,33 @@
+// (C) Copyright 2015 Martin Dougiamas
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { NgModule } from '@angular/core';
+import { IonicPageModule } from 'ionic-angular';
+import { TranslateModule } from '@ngx-translate/core';
+import { CoreComponentsModule } from '@components/components.module';
+import { CoreDirectivesModule } from '@directives/directives.module';
+import { AddonModForumSortOrderSelectorPage } from './sort-order-selector';
+
+@NgModule({
+    declarations: [
+        AddonModForumSortOrderSelectorPage,
+    ],
+    imports: [
+        CoreComponentsModule,
+        CoreDirectivesModule,
+        IonicPageModule.forChild(AddonModForumSortOrderSelectorPage),
+        TranslateModule.forChild()
+    ],
+})
+export class AddonModForumSortOrderSelectorPagePageModule {}

src/addon/mod/forum/pages/sort-order-selector/sort-order-selector.ts

@@ -0,0 +1,51 @@
+// (C) Copyright 2015 Martin Dougiamas
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Component } from '@angular/core';
+import { IonicPage, NavParams, ViewController } from 'ionic-angular';
+
+/**
+ * Page that displays the sort selector.
+ */
+@IonicPage({ segment: 'addon-mod-forum-sort-order-selector' })
+@Component({
+    selector: 'page-addon-mod-forum-sort-order-selector',
+    templateUrl: 'sort-order-selector.html',
+})
+export class AddonModForumSortOrderSelectorPage {
+
+    sortOrders = [];
+    selected: number;
+
+    constructor(navParams: NavParams, private viewCtrl: ViewController) {
+        this.sortOrders = navParams.get('sortOrders');
+        this.selected = navParams.get('selected');
+    }
+
+    /**
+     * Close the modal.
+     */
+    closeModal(): void {
+        this.viewCtrl.dismiss();
+    }
+
+    /**
+     * Select a sort order.
+     *
+     * @param {any} sortOrder Selected sort order.
+     */
+    selectSortOrder(sortOrder: any): void {
+        this.viewCtrl.dismiss(sortOrder);
+    }
+}

src/addon/mod/forum/providers/forum.ts

@@ -14,7 +14,7 @@
 
 import { Injectable } from '@angular/core';
 import { TranslateService } from '@ngx-translate/core';
-import { CoreSite } from '@classes/site';
+import { CoreSite, CoreSiteWSPreSets } from '@classes/site';
 import { CoreAppProvider } from '@providers/app';
 import { CoreFilepoolProvider } from '@providers/filepool';
 import { CoreGroupsProvider } from '@providers/groups';
@@ -38,6 +38,14 @@ export class AddonModForumProvider {
     static CHANGE_DISCUSSION_EVENT = 'addon_mod_forum_lock_discussion';
     static MARK_READ_EVENT = 'addon_mod_forum_mark_read';
 
+    static PREFERENCE_SORTORDER = 'forum_discussionlistsortorder';
+    static SORTORDER_LASTPOST_DESC = 1;
+    static SORTORDER_LASTPOST_ASC = 2;
+    static SORTORDER_CREATED_DESC = 3;
+    static SORTORDER_CREATED_ASC = 4;
+    static SORTORDER_REPLIES_DESC = 5;
+    static SORTORDER_REPLIES_ASC = 6;
+
     protected ROOT_CACHE_KEY = 'mmaModForum:';
 
     constructor(private appProvider: CoreAppProvider,
@@ -105,10 +113,17 @@ export class AddonModForumProvider {
      * Get cache key for forum discussions list WS calls.
      *
      * @param  {number} forumId Forum ID.
-     * @return {string}         Cache key.
+     * @param  {number} sortOrder Sort order.
+     * @return {string} Cache key.
      */
-    protected getDiscussionsListCacheKey(forumId: number): string {
+    protected getDiscussionsListCacheKey(forumId: number, sortOrder: number): string {
-        return this.ROOT_CACHE_KEY + 'discussions:' + forumId;
+        let key = this.ROOT_CACHE_KEY + 'discussions:' + forumId;
+
+        if (sortOrder != AddonModForumProvider.SORTORDER_LASTPOST_DESC) {
+            key += ':' + sortOrder;
+        }
+
+        return key;
     }
 
     /**
@@ -452,10 +467,64 @@ export class AddonModForumProvider {
         });
     }
 
+    /**
+     * Return whether discussion lists can be sorted.
+     *
+     * @param {CoreSite} [site] Site. If not defined, current site.
+     * @return {boolean} True if discussion lists can be sorted.
+     */
+    isDiscussionListSortingAvailable(site?: CoreSite): boolean {
+        site = site || this.sitesProvider.getCurrentSite();
+
+        return site.isVersionGreaterEqualThan('3.7');
+    }
+
+    /**
+     * Return the list of available sort orders.
+     *
+     * @return {{label: string, value: number}[]} List of sort orders.
+     */
+    getAvailableSortOrders(): {label: string, value: number}[] {
+        const sortOrders = [
+            {
+                label: 'addon.mod_forum.bylastpostdesc',
+                value: AddonModForumProvider.SORTORDER_LASTPOST_DESC
+            },
+        ];
+
+        if (this.isDiscussionListSortingAvailable()) {
+            sortOrders.push(
+                {
+                    label: 'addon.mod_forum.bylastpostasc',
+                    value: AddonModForumProvider.SORTORDER_LASTPOST_ASC
+                },
+                {
+                    label: 'addon.mod_forum.bycreateddesc',
+                    value: AddonModForumProvider.SORTORDER_CREATED_DESC
+                },
+                {
+                    label: 'addon.mod_forum.bycreatedasc',
+                    value: AddonModForumProvider.SORTORDER_CREATED_ASC
+                },
+                {
+                    label: 'addon.mod_forum.byrepliesdesc',
+                    value: AddonModForumProvider.SORTORDER_REPLIES_DESC
+                },
+                {
+                    label: 'addon.mod_forum.byrepliesasc',
+                    value: AddonModForumProvider.SORTORDER_REPLIES_ASC
+                }
+            );
+        }
+
+        return sortOrders;
+    }
+
     /**
      * Get forum discussions.
      *
      * @param  {number}  forumId      Forum ID.
+     * @param  {number}  [sortOrder]  Sort order.
      * @param  {number}  [page=0]     Page.
      * @param  {boolean} [forceCache] True to always get the value from cache. false otherwise.
      * @param  {string}  [siteId]     Site ID. If not defined, current site.
@@ -463,23 +532,59 @@ export class AddonModForumProvider {
      *                                 - discussions: List of discussions.
      *                                 - canLoadMore: True if there may be more discussions to load.
      */
-    getDiscussions(forumId: number, page: number = 0, forceCache?: boolean, siteId?: string): Promise<any> {
+    getDiscussions(forumId: number, sortOrder?: number, page: number = 0, forceCache?: boolean, siteId?: string): Promise<any> {
+        sortOrder = sortOrder || AddonModForumProvider.SORTORDER_LASTPOST_DESC;
+
         return this.sitesProvider.getSite(siteId).then((site) => {
-            const params = {
+            let method = 'mod_forum_get_forum_discussions_paginated';
+            const params: any = {
                 forumid: forumId,
-                sortby:  'timemodified',
-                sortdirection:  'DESC',
                 page: page,
                 perpage: AddonModForumProvider.DISCUSSIONS_PER_PAGE
             };
-            const preSets: any = {
+
-                cacheKey: this.getDiscussionsListCacheKey(forumId)
+            if (site.wsAvailable('mod_forum_get_forum_discussions')) {
+                // Since Moodle 3.7.
+                method = 'mod_forum_get_forum_discussions';
+                params.sortorder = sortOrder;
+            } else {
+                if (sortOrder == AddonModForumProvider.SORTORDER_LASTPOST_DESC) {
+                    params.sortby = 'timemodified';
+                    params.sortdirection = 'DESC';
+                } else {
+                    // Sorting not supported with the old WS method.
+                    return Promise.reject(null);
+                }
+            }
+            const preSets: CoreSiteWSPreSets = {
+                cacheKey: this.getDiscussionsListCacheKey(forumId, sortOrder)
             };
             if (forceCache) {
                 preSets.omitExpires = true;
             }
 
-            return site.read('mod_forum_get_forum_discussions_paginated', params, preSets).then((response) => {
+            return site.read(method, params, preSets).catch((error) => {
+                // Try to get the data from cache stored with the old WS method.
+                if (!this.appProvider.isOnline() && method == 'mod_forum_get_forum_discussion' &&
+                        sortOrder == AddonModForumProvider.SORTORDER_LASTPOST_DESC) {
+
+                    const params = {
+                        forumid: forumId,
+                        page: page,
+                        perpage: AddonModForumProvider.DISCUSSIONS_PER_PAGE,
+                        sortby: 'timemodified',
+                        sortdirection: 'DESC'
+                    };
+                    const preSets: CoreSiteWSPreSets = {
+                        cacheKey: this.getDiscussionsListCacheKey(forumId, sortOrder),
+                        omitExpires: true
+                    };
+
+                    return site.read('mod_forum_get_forum_discussions_paginated', params, preSets);
+                }
+
+                return Promise.reject(error);
+            }).then((response) => {
                 if (response) {
                     this.storeUserData(response.discussions);
 
@@ -499,7 +604,8 @@ export class AddonModForumProvider {
      * If a page fails, the discussions until that page will be returned along with a flag indicating an error occurred.
      *
      * @param  {number}  forumId     Forum ID.
-     * @param  {boolean} forceCache  True to always get the value from cache, false otherwise.
+     * @param  {number}  [sortOrder] Sort order.
+     * @param  {boolean} [forceCache] True to always get the value from cache, false otherwise.
      * @param  {number}  [numPages]  Number of pages to get. If not defined, all pages.
      * @param  {number}  [startPage] Page to start. If not defined, first page.
      * @param  {string}  [siteId]    Site ID. If not defined, current site.
@@ -507,8 +613,8 @@ export class AddonModForumProvider {
      *                                - discussions: List of discussions.
      *                                - error: True if an error occurred, false otherwise.
      */
-    getDiscussionsInPages(forumId: number, forceCache?: boolean, numPages?: number, startPage?: number, siteId?: string)
+    getDiscussionsInPages(forumId: number, sortOrder?: number, forceCache?: boolean, numPages?: number, startPage?: number,
-            : Promise<any> {
+            siteId?: string): Promise<any> {
         if (typeof numPages == 'undefined') {
             numPages = -1;
         }
@@ -525,7 +631,7 @@ export class AddonModForumProvider {
 
         const getPage = (page: number): Promise<any> => {
             // Get page discussions.
-            return this.getDiscussions(forumId, page, forceCache, siteId).then((response) => {
+            return this.getDiscussions(forumId, sortOrder, page, forceCache, siteId).then((response) => {
                 result.discussions = result.discussions.concat(response.discussions);
                 numPages--;
 
@@ -569,22 +675,32 @@ export class AddonModForumProvider {
     invalidateContent(moduleId: number, courseId: number): Promise<any> {
         // Get the forum first, we need the forum ID.
         return this.getForum(courseId, moduleId).then((forum) => {
-            // We need to get the list of discussions to be able to invalidate their posts.
+            const promises = [];
-            return this.getDiscussionsInPages(forum.id, true).then((response) => {
-                // Now invalidate the WS calls.
-                const promises = [];
 
-                promises.push(this.invalidateForumData(courseId));
+            promises.push(this.invalidateForumData(courseId));
-                promises.push(this.invalidateDiscussionsList(forum.id));
+            promises.push(this.invalidateDiscussionsList(forum.id));
-                promises.push(this.invalidateCanAddDiscussion(forum.id));
+            promises.push(this.invalidateCanAddDiscussion(forum.id));
-                promises.push(this.invalidateAccessInformation(forum.id));
+            promises.push(this.invalidateAccessInformation(forum.id));
 
-                response.discussions.forEach((discussion) => {
+            this.getAvailableSortOrders().forEach((sortOrder) => {
-                    promises.push(this.invalidateDiscussionPosts(discussion.discussion));
+                // We need to get the list of discussions to be able to invalidate their posts.
-                });
+                promises.push(this.getDiscussionsInPages(forum.id, sortOrder.value, true).then((response) => {
+                    // Now invalidate the WS calls.
+                    const promises = [];
 
-                return this.utils.allPromises(promises);
+                    response.discussions.forEach((discussion) => {
+                        promises.push(this.invalidateDiscussionPosts(discussion.discussion));
+                    });
+
+                    return this.utils.allPromises(promises);
+                }));
             });
+
+            if (this.isDiscussionListSortingAvailable()) {
+                promises.push(this.userProvider.invalidateUserPreference(AddonModForumProvider.PREFERENCE_SORTORDER));
+            }
+
+            return this.utils.allPromises(promises);
         });
     }
 
@@ -623,7 +739,9 @@ export class AddonModForumProvider {
      */
     invalidateDiscussionsList(forumId: number, siteId?: string): Promise<any> {
         return this.sitesProvider.getSite(siteId).then((site) => {
-            return site.invalidateWsCacheForKey(this.getDiscussionsListCacheKey(forumId));
+            return this.utils.allPromises(this.getAvailableSortOrders().map((sortOrder) => {
+                return site.invalidateWsCacheForKey(this.getDiscussionsListCacheKey(forumId, sortOrder.value));
+            }));
         });
     }
 

src/addon/mod/forum/providers/helper.ts

@@ -162,7 +162,7 @@ export class AddonModForumHelperProvider {
         siteId = siteId || this.sitesProvider.getCurrentSiteId();
 
         const findDiscussion = (page: number): Promise<any> => {
-            return this.forumProvider.getDiscussions(forumId, page, false, siteId).then((response) => {
+            return this.forumProvider.getDiscussions(forumId, undefined, page, false, siteId).then((response) => {
                 if (response.discussions && response.discussions.length > 0) {
                     const discussion = response.discussions.find((discussion) => discussion.id == discussionId);
                     if (discussion) {

src/addon/mod/forum/providers/prefetch-handler.ts

@@ -25,7 +25,7 @@ import { CoreGroupsProvider } from '@providers/groups';
 import { CoreUserProvider } from '@core/user/providers/user';
 import { AddonModForumProvider } from './forum';
 import { AddonModForumSyncProvider } from './sync';
-import { CoreRatingProvider } from '@core/rating/providers/rating';
+import { CoreRatingProvider, CoreRatingInfo } from '@core/rating/providers/rating';
 
 /**
  * Handler to prefetch forums.
@@ -107,26 +107,36 @@ export class AddonModForumPrefetchHandler extends CoreCourseActivityPrefetchHand
      * @return {Promise<any[]>} Promise resolved with array of posts.
      */
     protected getPostsForPrefetch(forum: any): Promise<any[]> {
-        // Get discussions in first 2 pages.
+        const posts = {};
-        return this.forumProvider.getDiscussionsInPages(forum.id, false, 2).then((response) => {
+        const ratingInfos: CoreRatingInfo[] = [];
-            if (response.error) {
-                return Promise.reject(null);
-            }
 
-            const promises = [];
+        const promises = this.forumProvider.getAvailableSortOrders().map((sortOrder) => {
-            let posts = [];
+            // Get discussions in first 2 pages.
+            return this.forumProvider.getDiscussionsInPages(forum.id, sortOrder.value, false, 2).then((response) => {
+                if (response.error) {
+                    return Promise.reject(null);
+                }
 
-            response.discussions.forEach((discussion) => {
+                const promises = [];
-                promises.push(this.forumProvider.getDiscussionPosts(discussion.discussion).then((response) => {
-                    posts = posts.concat(response.posts);
 
-                    return this.ratingProvider.prefetchRatings('module', forum.cmid, forum.scale, forum.course,
+                response.discussions.forEach((discussion) => {
-                            response.ratinginfo);
+                    promises.push(this.forumProvider.getDiscussionPosts(discussion.discussion).then((response) => {
-                }));
+                        response.posts.forEach((post) => {
+                            posts[post.id] = post;
+                        });
+                        ratingInfos.push(response.ratinginfo);
+                    }));
+                });
+
+              return Promise.all(promises);
             });
+        });
 
-            return Promise.all(promises).then(() => {
+        return Promise.all(promises).then(() => {
-                return posts;
+            const ratingInfo = this.ratingProvider.mergeRatingInfos(ratingInfos);
+
+            return this.ratingProvider.prefetchRatings('module', forum.cmid, forum.scale, forum.course, ratingInfo).then(() => {
+                return this.utils.objectToArray(posts);
             });
         });
     }
@@ -210,6 +220,11 @@ export class AddonModForumPrefetchHandler extends CoreCourseActivityPrefetchHand
             // Prefetch access information.
             promises.push(this.forumProvider.getAccessInformation(forum.id));
 
+            // Prefetch sort order preference.
+            if (this.forumProvider.isDiscussionListSortingAvailable()) {
+               promises.push(this.userProvider.getUserPreference(AddonModForumProvider.PREFERENCE_SORTORDER));
+            }
+
             return Promise.all(promises);
         });
     }

src/assets/lang/en.json

@@ -483,6 +483,12 @@
     "addon.mod_forum.addanewtopic": "Add a new topic",
     "addon.mod_forum.addtofavourites": "Star this discussion",
     "addon.mod_forum.advanced": "Advanced",
+    "addon.mod_forum.bycreatedasc": "By creation date in ascending order",
+    "addon.mod_forum.bycreateddesc": "By creation date in descending order",
+    "addon.mod_forum.bylastpostasc": "By last post in ascending order",
+    "addon.mod_forum.bylastpostdesc": "By last post in descending order",
+    "addon.mod_forum.byrepliesasc": "By number of replies in ascending order",
+    "addon.mod_forum.byrepliesdesc": "By number of replies in descending order",
     "addon.mod_forum.cannotadddiscussion": "Adding discussions to this forum requires group membership.",
     "addon.mod_forum.cannotadddiscussionall": "You do not have permission to add a new discussion topic for all participants.",
     "addon.mod_forum.cannotcreatediscussion": "Could not create new discussion",
@@ -1734,6 +1740,7 @@
     "core.sizemb": "MB",
     "core.sizetb": "TB",
     "core.sorry": "Sorry...",
+    "core.sort": "Sort",
     "core.sortby": "Sort by",
     "core.start": "Start",
     "core.strftimedate": "%d %B %Y",

src/lang/en.json

@@ -223,6 +223,7 @@
     "sizemb": "MB",
     "sizetb": "TB",
     "sorry": "Sorry...",
+    "sort": "Sort",
     "sortby": "Sort by",
     "start": "Start",
     "strftimedate": "%d %B %Y",