Fixes #1270 - Parse the latest room message instead of directly using the body. Add an app wide attributed string caching layer.

ElementX/Sources/Other/HTMLParsing/AttributedStringBuilder.swift

@@ -16,6 +16,7 @@
 
 import DTCoreText
 import Foundation
+import LRUCache
 
 struct AttributedStringBuilder: AttributedStringBuilderProtocol {
     private let temporaryBlockquoteMarkingColor = UIColor.magenta
@@ -23,6 +24,8 @@ struct AttributedStringBuilder: AttributedStringBuilderProtocol {
     private let linkColor = UIColor.blue
     private let permalinkBaseURL: URL
     
+    private static var cache = LRUCache<String, AttributedString>(countLimit: 1000)
+    
     init(permalinkBaseURL: URL) {
         self.permalinkBaseURL = permalinkBaseURL
     }
@@ -31,12 +34,18 @@ struct AttributedStringBuilder: AttributedStringBuilderProtocol {
         guard let string else {
             return nil
         }
+        
+        if let cached = Self.cache.value(forKey: string) {
+            return cached
+        }
 
         let mutableAttributedString = NSMutableAttributedString(string: string)
         addLinks(mutableAttributedString)
         removeLinkColors(mutableAttributedString)
         
-        return try? AttributedString(mutableAttributedString, including: \.elementX)
+        let result = try? AttributedString(mutableAttributedString, including: \.elementX)
+        Self.cache.setValue(result, forKey: string)
+        return result
     }
         
     // Do not use the default HTML renderer of NSAttributedString because this method
@@ -52,6 +61,10 @@ struct AttributedStringBuilder: AttributedStringBuilderProtocol {
             return nil
         }
         
+        if let cached = Self.cache.value(forKey: htmlString) {
+            return cached
+        }
+        
         let defaultFont = UIFont.preferredFont(forTextStyle: .body)
         
         let parsingOptions: [String: Any] = [
@@ -83,7 +96,9 @@ struct AttributedStringBuilder: AttributedStringBuilderProtocol {
         replaceMarkedCodeBlocks(mutableAttributedString)
         removeDTCoreTextArtifacts(mutableAttributedString)
         
-        return try? AttributedString(mutableAttributedString, including: \.elementX)
+        let result = try? AttributedString(mutableAttributedString, including: \.elementX)
+        Self.cache.setValue(result, forKey: htmlString)
+        return result
     }
     
     // MARK: - Private

ElementX/Sources/Services/Room/RoomSummary/RoomEventStringBuilder.swift

@@ -15,6 +15,7 @@
 //
 
 import Foundation
+import MatrixRustSDK
 
 struct RoomEventStringBuilder {
     private let stateEventStringBuilder: RoomStateEventStringBuilder
@@ -37,15 +38,28 @@ struct RoomEventStringBuilder {
         case .failedToParseMessageLike, .failedToParseState:
             return prefix(L10n.commonUnsupportedEvent, with: sender)
         case .message:
-            guard let messageContent = eventItemProxy.content.asMessage() else { fatalError("Invalid message timeline item: \(eventItemProxy)") }
+            guard let messageContent = eventItemProxy.content.asMessage() else {
+                fatalError("Invalid message timeline item: \(eventItemProxy)")
+            }
+            
+            guard let messageType = messageContent.msgtype() else {
+                return prefix(messageContent.body(), with: sender)
+            }
             
             let message: String
-            switch messageContent.msgtype() {
+            switch messageType {
             // Message types that don't need a prefix.
             case .emote(content: let content):
                 let senderDisplayName = sender.displayName ?? sender.id
-                return AttributedString(L10n.commonEmote(senderDisplayName, content.body))
+                
+                if let attributedMessage = attributedMessageFrom(formattedBody: content.formatted) {
+                    return AttributedString(L10n.commonEmote(senderDisplayName, String(attributedMessage.characters)))
+                } else {
+                    return AttributedString(L10n.commonEmote(senderDisplayName, content.body))
+                }
             // Message types that should be prefixed with the sender's name.
+            case .audio:
+                message = L10n.commonAudio
             case .image:
                 message = L10n.commonImage
             case .video:
@@ -54,8 +68,19 @@ struct RoomEventStringBuilder {
                 message = L10n.commonFile
             case .location:
                 message = L10n.commonSharedLocation
-            default:
-                message = messageContent.body()
+            case .notice(content: let content):
+                if let attributedMessage = attributedMessageFrom(formattedBody: content.formatted) {
+                    message = String(attributedMessage.characters)
+                } else {
+                    message = content.body
+                }
+            case .text(content: let content):
+                
+                if let attributedMessage = attributedMessageFrom(formattedBody: content.formatted) {
+                    message = String(attributedMessage.characters)
+                } else {
+                    message = content.body
+                }
             }
             return prefix(message, with: sender)
         case .state(let stateKey, let state):
@@ -81,7 +106,7 @@ struct RoomEventStringBuilder {
         }
     }
     
-    func prefix(_ eventSummary: String, with sender: TimelineItemSender) -> AttributedString {
+    private func prefix(_ eventSummary: String, with sender: TimelineItemSender) -> AttributedString {
         let attributedEventSummary = AttributedString(eventSummary.trimmingCharacters(in: .whitespacesAndNewlines))
         if let senderDisplayName = sender.displayName,
            let attributedSenderDisplayName = try? AttributedString(markdown: "**\(senderDisplayName)**") {
@@ -91,4 +116,8 @@ struct RoomEventStringBuilder {
             return attributedEventSummary
         }
     }
+    
+    private func attributedMessageFrom(formattedBody: FormattedBody?) -> AttributedString? {
+        formattedBody.flatMap { AttributedStringBuilder(permalinkBaseURL: .homeDirectory).fromHTML($0.body) }
+    }
 }