function applySyncResponse(data, roomResponse, membership) { if (roomResponse.summary) { data = updateSummary(data, roomResponse.summary); } if (membership !== data.membership) { data = data.cloneIfNeeded(); data.membership = membership; } // state comes before timeline if (roomResponse.state) { data = roomResponse.state.events.reduce(processEvent, data); } if (roomResponse.timeline) { data = roomResponse.timeline.events.reduce(processEvent, data); } return data; } function processEvent(data, event) { if (event.type === "m.room.encryption") { if (!data.isEncrypted) { data = data.cloneIfNeeded(); data.isEncrypted = true; } } if (event.type === "m.room.name") { const newName = event.content && event.content.name; if (newName !== data.name) { data = data.cloneIfNeeded(); data.name = newName; } } else if (event.type === "m.room.message") { const content = event.content; const body = content && content.body; const msgtype = content && content.msgtype; if (msgtype === "m.text") { data = data.cloneIfNeeded(); data.lastMessageBody = body; } } else if (event.type === "m.room.canonical_alias") { const content = event.content; data = data.cloneIfNeeded(); data.canonicalAlias = content.alias; data.altAliases = content.alt_aliases; } return data; } function updateSummary(data, summary) { const heroes = summary["m.heroes"]; const inviteCount = summary["m.joined_member_count"]; const joinCount = summary["m.invited_member_count"]; if (heroes) { data = data.cloneIfNeeded(); data.heroes = heroes; } if (Number.isInteger(inviteCount)) { data = data.cloneIfNeeded(); data.inviteCount = inviteCount; } if (Number.isInteger(joinCount)) { data = data.cloneIfNeeded(); data.joinCount = joinCount; } return data; } class SummaryData { constructor(copy, roomId) { this.roomId = copy ? copy.roomId : roomId; this.name = copy ? copy.name : null; this.lastMessageBody = copy ? copy.lastMessageBody : null; this.unreadCount = copy ? copy.unreadCount : null; this.mentionCount = copy ? copy.mentionCount : null; this.isEncrypted = copy ? copy.isEncrypted : null; this.isDirectMessage = copy ? copy.isDirectMessage : null; this.membership = copy ? copy.membership : null; this.inviteCount = copy ? copy.inviteCount : 0; this.joinCount = copy ? copy.joinCount : 0; this.heroes = copy ? copy.heroes : null; this.canonicalAlias = copy ? copy.canonicalAlias : null; this.altAliases = copy ? copy.altAliases : null; this.cloned = copy ? true : false; } cloneIfNeeded() { if (this.cloned) { return this; } else { return new SummaryData(this); } } serialize() { const {cloned, ...serializedProps} = this; return serializedProps; } } export default class RoomSummary { constructor(roomId) { this._data = new SummaryData(null, roomId); } get name() { if (this._data.name) { return this._data.name; } if (this._data.canonicalAlias) { return this._data.canonicalAlias; } if (Array.isArray(this._data.altAliases) && this._data.altAliases.length !== 0) { return this._data.altAliases[0]; } if (Array.isArray(this._data.heroes) && this._data.heroes.length !== 0) { return this._data.heroes.join(", "); } return this._data.roomId; } get lastMessage() { return this._data.lastMessageBody; } get inviteCount() { return this._data.inviteCount; } get joinCount() { return this._data.joinCount; } writeSync(roomResponse, membership, txn) { // clear cloned flag, so cloneIfNeeded makes a copy and // this._data is not modified if any field is changed. this._data.cloned = false; const data = applySyncResponse(this._data, roomResponse, membership); if (data !== this._data) { // need to think here how we want to persist // things like unread status (as read marker, or unread count)? // we could very well load additional things in the load method // ... the trade-off is between constantly writing the summary // on every sync, or doing a bit of extra reading on load // and have in-memory only variables for visualization txn.roomSummary.set(data.serialize()); return data; } } afterSync(data) { this._data = data; } async load(summary) { this._data = new SummaryData(summary); } } export function tests() { return { "membership trigger change": function(assert) { const summary = new RoomSummary("id"); let written = false; const changes = summary.writeSync({}, "join", {roomSummary: {set: () => { written = true; }}}); assert(changes); assert(written); assert.equal(changes.membership, "join"); } } }