Merge pull request #4994 from vector-im/gil/4893_support_pagination_in_the_space_summary_api

Support pagination in the Space Summary API

Riot/Modules/Spaces/SpaceRoomList/ExploreRoom/PaginationLoadingViewCell.swift

@@ -0,0 +1,32 @@
+// 
+// Copyright 2021 New Vector Ltd
+//
+// 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 UIKit
+import Reusable
+
+class PaginationLoadingViewCell: UITableViewCell, NibReusable, Themable {
+    
+    // MARK: - Properties
+    
+    @IBOutlet var activityIndicator: UIActivityIndicatorView!
+    
+    // MARK: - Public
+    
+    func update(theme: Theme) {
+        self.activityIndicator.tintColor = theme.colors.tertiaryContent
+        self.activityIndicator.startAnimating()
+    }
+}

Riot/Modules/Spaces/SpaceRoomList/ExploreRoom/PaginationLoadingViewCell.xib

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="18122" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES">
+    <device id="retina6_1" orientation="portrait" appearance="light"/>
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="18093"/>
+        <capability name="Safe area layout guides" minToolsVersion="9.0"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <objects>
+        <placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner"/>
+        <placeholder placeholderIdentifier="IBFirstResponder" id="-2" customClass="UIResponder"/>
+        <tableViewCell contentMode="scaleToFill" selectionStyle="default" indentationWidth="10" rowHeight="68" id="gUf-SL-Ia7" customClass="PaginationLoadingViewCell" customModule="Riot" customModuleProvider="target">
+            <rect key="frame" x="0.0" y="0.0" width="320" height="68"/>
+            <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
+            <tableViewCellContentView key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" tableViewCell="gUf-SL-Ia7" id="YoL-49-1Hj">
+                <rect key="frame" x="0.0" y="0.0" width="320" height="68"/>
+                <autoresizingMask key="autoresizingMask"/>
+                <subviews>
+                    <activityIndicatorView opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" animating="YES" style="large" translatesAutoresizingMaskIntoConstraints="NO" id="Tld-uY-uDU">
+                        <rect key="frame" x="141.5" y="17" width="37" height="34"/>
+                    </activityIndicatorView>
+                </subviews>
+                <constraints>
+                    <constraint firstAttribute="bottom" secondItem="Tld-uY-uDU" secondAttribute="bottom" constant="17" id="cib-oa-sGv"/>
+                    <constraint firstItem="Tld-uY-uDU" firstAttribute="top" secondItem="YoL-49-1Hj" secondAttribute="top" constant="17" id="fuX-uS-ylN"/>
+                    <constraint firstItem="Tld-uY-uDU" firstAttribute="centerX" secondItem="YoL-49-1Hj" secondAttribute="centerX" id="ots-Sg-fHU"/>
+                </constraints>
+            </tableViewCellContentView>
+            <viewLayoutGuide key="safeArea" id="wBe-er-msB"/>
+            <connections>
+                <outlet property="activityIndicator" destination="Tld-uY-uDU" id="mq3-lG-y9D"/>
+            </connections>
+            <point key="canvasLocation" x="137.68115942028987" y="107.14285714285714"/>
+        </tableViewCell>
+    </objects>
+</document>

Riot/Modules/Spaces/SpaceRoomList/ExploreRoom/SpaceExploreRoomViewController.swift

@@ -41,10 +41,11 @@ final class SpaceExploreRoomViewController: UIViewController {
     private var titleView: MainTitleView!
     private var emptyView: RootTabEmptyView!
     private var plusButtonImageView: UIImageView!
+    private var hasMore: Bool = false
     
     private var itemDataList: [SpaceExploreRoomListItemViewData] = [] {
         didSet {
-            tableView.reloadData()
+            self.tableView.reloadData()
         }
     }
     
@@ -168,6 +169,7 @@ final class SpaceExploreRoomViewController: UIViewController {
         self.tableView.allowsSelection = true
         self.tableView.register(cellType: SpaceChildViewCell.self)
         self.tableView.register(cellType: SpaceChildSpaceViewCell.self)
+        self.tableView.register(cellType: PaginationLoadingViewCell.self)
         self.tableView.tableFooterView = UIView()
     }
 
@@ -177,7 +179,8 @@ final class SpaceExploreRoomViewController: UIViewController {
             self.renderLoading()
         case .spaceNameFound(let spaceName):
             self.titleView.subtitleLabel.text = spaceName
-        case .loaded(let children):
+        case .loaded(let children, let hasMore):
+            self.hasMore = hasMore
             self.renderLoaded(children: children)
         case .emptySpace:
             self.renderEmptySpace()
@@ -240,10 +243,16 @@ extension SpaceExploreRoomViewController: UITableViewDataSource {
     }
     
     func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        return self.itemDataList.count
+        return self.itemDataList.count + (self.hasMore ? 1 : 0)
     }
     
     func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+        guard indexPath.row < self.itemDataList.count else {
+            let cell = tableView.dequeueReusableCell(for: indexPath, cellType: PaginationLoadingViewCell.self)
+            cell.update(theme: self.theme)
+            return cell
+        }
+        
         let viewData = self.itemDataList[indexPath.row]
         
         let cell = viewData.childInfo.roomType == .space ? tableView.dequeueReusableCell(for: indexPath, cellType: SpaceChildSpaceViewCell.self) : tableView.dequeueReusableCell(for: indexPath, cellType: SpaceChildViewCell.self)
@@ -262,6 +271,12 @@ extension SpaceExploreRoomViewController: UITableViewDelegate {
         tableView.deselectRow(at: indexPath, animated: true)
         self.viewModel.process(viewAction: .complete(self.itemDataList[indexPath.row], tableView.cellForRow(at: indexPath)))
     }
+    
+    func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
+        if self.hasMore && indexPath.row >= self.itemDataList.count {
+            self.viewModel.process(viewAction: .loadData)
+        }
+    }
 }
 
 // MARK: - SpaceExploreRoomViewModelViewDelegate

Riot/Modules/Spaces/SpaceRoomList/ExploreRoom/SpaceExploreRoomViewModel.swift

@@ -29,13 +29,15 @@ final class SpaceExploreRoomViewModel: SpaceExploreRoomViewModelType {
     private let spaceName: String?
 
     private var currentOperation: MXHTTPOperation?
+    private var nextBatch: String?
+    private var rootSpaceChildInfo: MXSpaceChildInfo?
     
     private var itemDataList: [SpaceExploreRoomListItemViewData] = [] {
         didSet {
             self.updateFilteredItemList()
         }
     }
-    private var searchKeyword: String? = nil {
+    private var searchKeyword: String? {
         didSet {
             self.updateFilteredItemList()
         }
@@ -49,7 +51,7 @@ final class SpaceExploreRoomViewModel: SpaceExploreRoomViewModelType {
                     self.update(viewState: .emptyFilterResult)
                 }
             } else {
-                self.update(viewState: .loaded(self.filteredItemDataList))
+                self.update(viewState: .loaded(self.filteredItemDataList, self.nextBatch != nil && (self.searchKeyword ?? "").isEmpty))
             }
         }
     }
@@ -90,32 +92,51 @@ final class SpaceExploreRoomViewModel: SpaceExploreRoomViewModelType {
     // MARK: - Private
     
     private func loadData() {
+        guard self.currentOperation == nil else {
+            return
+        }
+        
         if let spaceName = self.spaceName {
             self.update(viewState: .spaceNameFound(spaceName))
         }
 
-        self.update(viewState: .loading)
+        if self.nextBatch == nil {
+            self.update(viewState: .loading)
+        }
         
-        self.currentOperation = self.session.spaceService.getSpaceChildrenForSpace(withId: self.spaceId, suggestedOnly: false, limit: nil, completion: { [weak self] response in
+        self.currentOperation = self.session.spaceService.getSpaceChildrenForSpace(withId: self.spaceId, suggestedOnly: false, limit: nil, maxDepth: 1, paginationToken: self.nextBatch, completion: { [weak self] response in
             guard let self = self else {
                 return
             }
             
             switch response {
             case .success(let spaceSummary):
-                self.itemDataList = spaceSummary.childInfos.compactMap({ childInfo in
-                    guard childInfo.parentIds.contains(self.spaceId) else {
+                self.nextBatch = spaceSummary.nextBatch
+                // The MXSpaceChildInfo of the root space is available only in the first batch
+                if let rootSpaceInfo = spaceSummary.spaceInfo {
+                    self.rootSpaceChildInfo = rootSpaceInfo
+                }
+                
+                let batchedItemDataList: [SpaceExploreRoomListItemViewData] = spaceSummary.childInfos.compactMap({ childInfo in
+                    guard let rootSpaceInfo = self.rootSpaceChildInfo, rootSpaceInfo.childrenIds.contains(childInfo.childRoomId) else {
                         return nil
                     }
                     
-                    let avatarViewData = AvatarViewData(matrixItemId: childInfo.childRoomId, displayName: childInfo.displayName, avatarUrl: childInfo.avatarUrl, mediaManager: self.session.mediaManager, fallbackImage: .matrixItem(childInfo.childRoomId, childInfo.name))
+                    let avatarViewData = AvatarViewData(matrixItemId: childInfo.childRoomId,
+                                                        displayName: childInfo.displayName,
+                                                        avatarUrl: childInfo.avatarUrl,
+                                                        mediaManager: self.session.mediaManager,
+                                                        fallbackImage: .matrixItem(childInfo.childRoomId, childInfo.name))
                     return SpaceExploreRoomListItemViewData(childInfo: childInfo, avatarViewData: avatarViewData)
                 }).sorted(by: { item1, item2 in
                     return !item2.childInfo.suggested || item1.childInfo.suggested
                 })
+                self.itemDataList.append(contentsOf: batchedItemDataList)
             case .failure(let error):
                 self.update(viewState: .error(error))
             }
+            
+            self.currentOperation = nil
         })
     }
     

Riot/Modules/Spaces/SpaceRoomList/ExploreRoom/SpaceExploreRoomViewState.swift

@@ -22,7 +22,7 @@ import Foundation
 enum SpaceExploreRoomViewState {
     case loading
     case spaceNameFound(_ spaceName: String)
-    case loaded(_ children: [SpaceExploreRoomListItemViewData])
+    case loaded(_ children: [SpaceExploreRoomListItemViewData], _ hasMore: Bool)
     case emptySpace
     case emptyFilterResult
     case error(Error)