WIP

src/domain/session/room/timeline/ReactionsViewModel.js

@@ -254,8 +254,16 @@ export function tests() {
             // 2. setup queue & timeline
             const queue = new SendQueue({roomId, storage, hsApi: new MockHomeServer().api});
             const powerLevelsObservable = new ObservableValue(new PowerLevels({ ownUserId: alice, membership: "join" }));
-            const timeline = new Timeline({roomId, storage, fragmentIdComparer,
-                clock: new MockClock(), pendingEvents: queue.pendingEvents, powerLevelsObservable});
+            const timeline = new Timeline({
+                roomId,
+                storage,
+                fragmentIdComparer,
+                clock: new MockClock(),
+                pendingEvents: queue.pendingEvents,
+                powerLevelsObservable,
+                fetchEventFromHomeserver: () => {},
+                fetchEventFromStorage: () => {}
+            });
             // 3. load the timeline, which will load the message with the reaction
             await timeline.load(new User(alice), "join", new NullLogItem());
             const tiles = mapMessageEntriesToBaseMessageTile(timeline, queue);

src/matrix/net/HomeServerApi.ts

@@ -128,6 +128,10 @@ export class HomeServerApi {
         return this._get("/sync", {since, timeout, filter}, undefined, options);
     }
 
+    event(roomId, eventId) {
+        return this._get(`/rooms/${encodeURIComponent(roomId)}/event/${encodeURIComponent(eventId)}`);
+    }
+
     // params is from, dir and optionally to, limit, filter.
     messages(roomId: string, params: Record<string, any>, options?: IRequestOptions): IHomeServerRequest {
         return this._get(`/rooms/${encodeURIComponent(roomId)}/messages`, params, undefined, options);

src/matrix/room/BaseRoom.js

@@ -501,7 +501,9 @@ export class BaseRoom extends EventEmitter {
                 },
                 clock: this._platform.clock,
                 logger: this._platform.logger,
-                powerLevelsObservable: await this.observePowerLevels()
+                powerLevelsObservable: await this.observePowerLevels(),
+                fetchEventFromStorage: eventId => this._readEventById(eventId),
+                fetchEventFromHomeserver: eventId => this._getEventFromHomeserver(eventId)
             });
             try {
                 if (this._roomEncryption) {
@@ -559,6 +561,12 @@ export class BaseRoom extends EventEmitter {
         }
     }
 
+    async _getEventFromHomeserver(eventId) {
+        const response = await this._hsApi.event(this._roomId, eventId).response();
+        const entry = new EventEntry({ event: response }, this._fragmentIdComparer);
+        return entry;
+    }
+
 
     dispose() {
         this._roomEncryption?.dispose();

src/matrix/room/timeline/Timeline.js

@@ -25,8 +25,10 @@ import {getRelation, ANNOTATION_RELATION_TYPE} from "./relations.js";
 import {REDACTION_TYPE} from "../common.js";
 
 export class Timeline {
-    constructor({roomId, storage, closeCallback, fragmentIdComparer, pendingEvents, clock, powerLevelsObservable}) {
+    constructor({roomId, storage, closeCallback, fragmentIdComparer, pendingEvents, clock, powerLevelsObservable, fetchEventFromStorage, fetchEventFromHomeserver}) {
         this._roomId = roomId;
+        this._fetchEventFromStorage = fetchEventFromStorage;
+        this._fetchEventFromHomeserver = fetchEventFromHomeserver;
         this._storage = storage;
         this._closeCallback = closeCallback;
         this._fragmentIdComparer = fragmentIdComparer;
@@ -78,6 +80,7 @@ export class Timeline {
         const readerRequest = this._disposables.track(this._timelineReader.readFromEnd(20, txn, log));
         try {
             const entries = await readerRequest.complete();
+            await this._loadRelatedEvents(entries);
             this._setupEntries(entries);
         } finally {
             this._disposables.disposeTracked(readerRequest);
@@ -213,6 +216,7 @@ export class Timeline {
     /** @package */
      replaceEntries(entries) {
         this._addLocalRelationsToNewRemoteEntries(entries);
+        this._loadRelatedEvents(entries);
         for (const entry of entries) {
             try {
                 this._remoteEntries.getAndUpdate(entry, Timeline._entryUpdater);
@@ -236,9 +240,31 @@ export class Timeline {
     /** @package */
     addEntries(newEntries) {
         this._addLocalRelationsToNewRemoteEntries(newEntries);
+        this._loadRelatedEvents(newEntries);
         this._remoteEntries.setManySorted(newEntries);
     }
 
+    async _loadRelatedEvents(entries) {
+        const filteredEntries = entries.filter(e => !!e.relation);
+        for (const entry of filteredEntries) {
+            const id = entry.relatedEventId;
+            let relatedEvent;
+            // find in remote events
+            relatedEvent = this.getByEventId(id);
+            // find in storage
+            if (!relatedEvent) {
+                relatedEvent = await this._fetchEventFromStorage(id);
+            }
+            // fetch from hs
+            if (!relatedEvent) {
+                relatedEvent = await this._fetchEventFromHomeserver(id);
+            }
+            if (relatedEvent) {
+                entry.setRelatedEntry(relatedEvent);
+            }
+        }
+    }
+    
     // tries to prepend `amount` entries to the `entries` list.
     /**
      * [loadAtTop description]

src/matrix/room/timeline/entries/EventEntry.js

@@ -24,6 +24,7 @@ export class EventEntry extends BaseEventEntry {
         this._eventEntry = eventEntry;
         this._decryptionError = null;
         this._decryptionResult = null;
+        this._relatedEntry = null;
     }
 
     clone() {
@@ -41,6 +42,10 @@ export class EventEntry extends BaseEventEntry {
         }
     }
 
+    setRelatedEntry(entry) {
+        this._relatedEntry = entry;
+    }
+
     get event() {
         return this._eventEntry.event;
     }
@@ -122,6 +127,10 @@ export class EventEntry extends BaseEventEntry {
         return getRelatedEventId(this.event);
     }
 
+    get relatedEntry() {
+        return this._relatedEntry;
+    }
+
     get isRedacted() {
         return super.isRedacted || isRedacted(this._eventEntry.event);
     }