Open markdown formatter (#978)

* Open markdown formatter (#974)

* Refactor markdownFormatter to use DefaultMarkdownFormatter and update MarkdownFormatter protocol for improved formatting capabilities

* Update Utils to allow custom markdownFormatter initialization

* feat(Formatter): make format method open for better accessibility

* Update CHANGELOG.md

---------

Co-authored-by: Hossam Youssof <eng.hossam.youssof@gmail.com>

Author: nuno-vieira

CHANGELOG.md

@@ -4,7 +4,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 # Upcoming
 
 ### ✅ Added
-- Make the commandsHandler and the mention methods public to allow customization of the mention command handler [#979](https://github.com/GetStream/stream-chat-swiftui/pull/979)
+- Opens the `commandsHandler` and makes the mention methods public [#979](https://github.com/GetStream/stream-chat-swiftui/pull/979)
+- Opens `MarkdownFormatter` so that it can be customised [#978](https://github.com/GetStream/stream-chat-swiftui/pull/978)
 
 ### 🐞 Fixed
 - Fix openChannel not working when searching or another chat shown [#975](https://github.com/GetStream/stream-chat-swiftui/pull/975)

Sources/StreamChatSwiftUI/Utils.swift

@@ -8,7 +8,7 @@ import StreamChat
 /// Class providing implementations of several utilities used in the SDK.
 /// The default implementations can be replaced in the init method, or directly via the variables.
 public class Utils {
-    var markdownFormatter = MarkdownFormatter()
+    public var markdownFormatter: MarkdownFormatter
 
     public var dateFormatter: DateFormatter
 
@@ -76,6 +76,7 @@ public class Utils {
     internal var pollsDateFormatter = PollsDateFormatter()
 
     public init(
+        markdownFormatter: MarkdownFormatter = DefaultMarkdownFormatter(),
         dateFormatter: DateFormatter = .makeDefault(),
         messageRelativeDateFormatter: DateFormatter = MessageRelativeDateFormatter(),
         galleryHeaderViewDateFormatter: DateFormatter = GalleryHeaderViewDateFormatter(),
@@ -104,6 +105,7 @@ public class Utils {
         sortReactions: @escaping (MessageReactionType, MessageReactionType) -> Bool = Utils.defaultSortReactions,
         shouldSyncChannelControllerOnAppear: @escaping (ChatChannelController) -> Bool = { _ in true }
     ) {
+        self.markdownFormatter = markdownFormatter
         self.dateFormatter = dateFormatter
         self.messageRelativeDateFormatter = messageRelativeDateFormatter
         self.galleryHeaderViewDateFormatter = galleryHeaderViewDateFormatter

Sources/StreamChatSwiftUI/Utils/MarkdownFormatter.swift

@@ -6,15 +6,34 @@ import Foundation
 import StreamChat
 import SwiftUI
 
+public protocol MarkdownFormatter {
+    /// Formats a Markdown string into an `AttributedString`, merging Markdown styles with the provided base attributes and honoring the given layout direction.
+    /// - Parameters:
+    ///   - string: The Markdown-formatted source string to render.
+    ///   - attributes: Base attributes applied to the entire string; Markdown-specific styling is merged on top of these defaults.
+    ///   - layoutDirection: The text layout direction (left-to-right or right-to-left) used when interpreting and rendering Markdown blocks (for example, lists, block quotes, and headings).
+    /// - Returns: An `AttributedString` containing the rendered Markdown with the resolved attributes.
+    @available(iOS 15, *)
+    func format(
+        _ string: String,
+        attributes: AttributeContainer,
+        layoutDirection: LayoutDirection
+    ) -> AttributedString
+}
+
 /// Converts markdown string to AttributedString with styling attributes.
-final class MarkdownFormatter {
+open class DefaultMarkdownFormatter: MarkdownFormatter {
     @Injected(\.colors) private var colors
     @Injected(\.fonts) private var fonts
 
-    private let markdownParser = MarkdownParser()
+    private let markdownParser: MarkdownParser
+    
+    public init() {
+        markdownParser = MarkdownParser()
+    }
 
     @available(iOS 15, *)
-    func format(
+    open func format(
         _ string: String,
         attributes: AttributeContainer,
         layoutDirection: LayoutDirection