add attribute for spoilers

ElementX/Sources/Other/HTMLParsing/AttributedStringBuilder.swift

@@ -32,6 +32,7 @@ extension NSAttributedString.Key {
     static let MatrixEventOnRoomAlias: NSAttributedString.Key = .init(rawValue: EventOnRoomAliasAttribute.name)
     static let MatrixAllUsersMention: NSAttributedString.Key = .init(rawValue: AllUsersMentionAttribute.name)
     static let CodeBlock: NSAttributedString.Key = .init(rawValue: CodeBlockAttribute.name)
+    static let MatrixSpoiler: NSAttributedString.Key = .init(rawValue: SpoilerAttribute.name)
 }
 
 struct AttributedStringBuilder: AttributedStringBuilderProtocol {

ElementX/Sources/Other/HTMLParsing/AttributedStringBuilderV2.swift

@@ -16,6 +16,7 @@ struct AttributedStringBuilderV2: AttributedStringBuilderProtocol {
     private let mentionBuilder: MentionBuilderProtocol
 
     private static let attributeMSC4286 = "data-msc4286-external-payment-details"
+    private static let attributeMSC2010 = "mx-spoiler"
     private static let cacheDispatchQueue = DispatchQueue(label: "io.element.elementx.attributed_string_builder_v2_cache")
     private static var caches: [String: LRUCache<String, AttributedString>] = [:]
 
@@ -203,6 +204,10 @@ struct AttributedStringBuilderV2: AttributedStringBuilderProtocol {
                 if childElement.dataset()[Self.attributeMSC4286] != nil {
                     content = attributedString(element: childElement, documentBody: documentBody, preserveFormatting: preserveFormatting, listTag: listTag, listIndex: &childIndex, indentLevel: indentLevel)
                 }
+                if childElement.dataset()[Self.attributeMSC2010] != nil {
+                    content = attributedString(element: childElement, documentBody: documentBody, preserveFormatting: preserveFormatting, listTag: listTag, listIndex: &childIndex, indentLevel: indentLevel)
+                    content.addAttribute(.MatrixSpoiler, value: true, range: NSRange(location: 0, length: content.length))
+                }
 
             case "ul", "ol":
                 var listIndex = 1

ElementX/Sources/Other/HTMLParsing/ElementXAttributeScope.swift

@@ -67,6 +67,11 @@ enum CodeBlockAttribute: AttributedStringKey {
     static let name = "MXCodeBlockAttribute"
 }
 
+enum SpoilerAttribute: AttributedStringKey {
+    typealias Value = Bool
+    static let name = "MXSpoilerAttribute"
+}
+
 // periphery: ignore - required to make NSAttributedString to AttributedString conversion even if not used directly
 extension AttributeScopes {
     struct ElementXAttributes: AttributeScope {

ElementX/Sources/Other/HTMLParsing/HTMLFixtures.swift

@@ -17,6 +17,8 @@ enum HTMLFixtures: String, CaseIterable {
     case codeBlocks
     case unorderedList
     case orderedList
+    case entirelySpoilered
+    case partiallySpoilered
 
     var rawValue: String {
         switch self {
@@ -111,6 +113,14 @@ enum HTMLFixtures: String, CaseIterable {
             <li>Skittles</li>
             </ol>
             """
+        case .partiallySpoilered:
+            """
+            partially <span data-mx-spoiler>spoilered</span>
+            """
+        case .entirelySpoilered:
+            """
+            <span data-mx-spoiler>entirely spoilered</span>
+            """
         }
     }
 }

ElementX/Sources/Other/Pills/MessageText.swift

@@ -203,6 +203,8 @@ struct MessageText_Previews: PreviewProvider, TestablePreview {
         """
 
     private static let htmlStringWithList = "<p>This is a list</p>\n<ul>\n<li>One</li>\n<li>Two</li>\n<li>And number 3</li>\n</ul>\n"
+
+    private static let htmlStringWithSpoiler = "partially <span data-mx-spoiler>spoilered</span>"
 
     private static let attributedStringBuilder = AttributedStringBuilder(mentionBuilder: MentionBuilder())
 
@@ -232,5 +234,10 @@ struct MessageText_Previews: PreviewProvider, TestablePreview {
                 .border(Color.purple)
                 .previewDisplayName("With list")
         }
+        if let attributedString = attributedStringBuilder.fromHTML(htmlStringWithSpoiler) {
+            MessageText(attributedString: attributedString)
+                .border(Color.purple)
+                .previewDisplayName("With spoiler")
+        }
     }
 }