InstantPage blockQuote: nested-blocks payload

Upgrade InstantPageBlock.blockQuote from (text, caption) to
(blocks: [InstantPageBlock], caption). Legacy inbound shapes (API
pageBlockBlockquote, Postbox "t", FlatBuffers text) lift into
[.paragraph(text)]; outbound stays on the legacy wire constructor for
empty/single-paragraph quotes and uses pageBlockBlockquoteBlocks
otherwise. V1/V2 renderers recurse into child blocks with a fixed 10pt
inter-child gap; markdown forward/reverse, entity-expressibility, and
preview text updated. pullQuote is unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

submodules/BrowserUI/Sources/BrowserMarkdown.swift

@@ -1116,8 +1116,14 @@ private func blockIsEntityExpressible(_ block: InstantPageBlock) -> Bool {
         return richTextIsEntityExpressible(text)
     case .preformatted(let text, _):
         return richTextIsEntityExpressible(text)
-    case .blockQuote(let text, let caption):
-        return isEmptyRichText(caption) && richTextIsEntityExpressible(text)
+    case .blockQuote(let blocks, let caption):
+        guard isEmptyRichText(caption) else { return false }
+        return blocks.allSatisfy { child in
+            if case let .paragraph(text) = child {
+                return richTextIsEntityExpressible(text)
+            }
+            return false
+        }
     case .anchor, .unsupported:
         return true
     case .divider:
@@ -1392,24 +1398,17 @@ private func markdownBlocks(from node: MarkdownIntentNode, context: MarkdownConv
     case .thematicBreak:
         return [.divider]
     case .blockQuote:
-        var result: [InstantPageBlock] = []
+        var childBlocks: [InstantPageBlock] = []
         for child in node.children {
-            guard let childBlocks = markdownBlocks(from: child, context: context, depth: depth + 1) else {
+            guard let parsed = markdownBlocks(from: child, context: context, depth: depth + 1) else {
                 return nil
             }
-            for childBlock in childBlocks {
-                switch childBlock {
-                case let .paragraph(text):
-                    result.append(.blockQuote(text: text, caption: .empty))
-                default:
-                    let plainText = markdownPlainText(from: childBlock, depth: depth + 1)
-                    if !plainText.isEmpty {
-                        result.append(.blockQuote(text: .plain(plainText), caption: .empty))
-                    }
-                }
-            }
+            childBlocks.append(contentsOf: parsed)
         }
-        return result
+        guard !childBlocks.isEmpty else {
+            return []
+        }
+        return [.blockQuote(blocks: childBlocks, caption: .empty)]
     case .orderedList:
         guard let items = markdownListItems(from: node.children, ordered: true, context: context, depth: depth + 1) else {
             return nil
@@ -2213,8 +2212,9 @@ private func markdownPlainText(from block: InstantPageBlock, depth: Int = 0) ->
         return text.plainText
     case let .footer(text):
         return text.plainText
-    case let .blockQuote(text, caption):
-        return text.plainText.isEmpty ? caption.plainText : text.plainText
+    case let .blockQuote(blocks, caption):
+        let blocksText = blocks.map { markdownPlainText(from: $0, depth: depth + 1) }.joined(separator: "\n")
+        return blocksText.isEmpty ? caption.plainText : blocksText
     case let .pullQuote(text, caption):
         return text.plainText.isEmpty ? caption.plainText : text.plainText
     case let .kicker(text):

submodules/BrowserUI/Sources/BrowserReadability.swift

@@ -781,7 +781,7 @@ private func parsePageBlocks(_ input: [Any], _ url: String, _ media: inout [Engi
             case "pre":
                 result.append(.preformatted(text: .fixed(trim(parseRichText(item, &media))), language: nil))
             case "blockquote":
-                result.append(.blockQuote(text: .italic(trim(parseRichText(item, &media))), caption: .empty))
+                result.append(.blockQuote(blocks: [.paragraph(.italic(trim(parseRichText(item, &media))))], caption: .empty))
             case "img":
                 if let image = parseImage(item, &media) {
                     result.append(image)

submodules/BrowserUI/Sources/InstantPageToMarkdown.swift

@@ -39,8 +39,8 @@ private func markdownString(from block: InstantPageBlock) -> String? {
     case let .preformatted(text, language):
         let language = language ?? ""
         return "```\(language)\n\(markdownInline(from: text))\n```"
-    case let .blockQuote(text, _):
-        return markdownBlockQuote(text)
+    case let .blockQuote(blocks, _):
+        return markdownBlockQuoteBlocks(blocks)
     case let .pullQuote(text, _):
         return markdownBlockQuote(text)
     case let .list(items, ordered):
@@ -69,6 +69,19 @@ private func markdownBlockQuote(_ text: RichText) -> String {
     return lines.map { "> \($0)" }.joined(separator: "\n")
 }
 
+private func markdownBlockQuoteBlocks(_ blocks: [InstantPageBlock]) -> String {
+    var lines: [String] = []
+    for block in blocks {
+        guard let body = markdownString(from: block) else {
+            continue
+        }
+        for line in body.split(separator: "\n", omittingEmptySubsequences: false) {
+            lines.append("> \(String(line))")
+        }
+    }
+    return lines.joined(separator: "\n")
+}
+
 private func markdownInline(from richText: RichText) -> String {
     switch richText {
     case .empty:

submodules/InstantPageUI/Sources/InstantPageLayout.swift

@@ -501,40 +501,65 @@ public func layoutInstantPageBlock(webpage: TelegramMediaWebpage, userLocation:
                 }
             }
             return InstantPageLayout(origin: CGPoint(), contentSize: contentSize, items: listItems)
-        case let .blockQuote(text, caption):
+        case let .blockQuote(blocks, caption):
             let lineInset: CGFloat = 20.0
             let verticalInset: CGFloat = 4.0
             var contentSize = CGSize(width: boundingWidth, height: verticalInset)
-            
+
             var items: [InstantPageItem] = []
-            
-            let styleStack = InstantPageTextStyleStack()
-            setupStyleStack(styleStack, theme: theme, category: .paragraph, link: false)
-            styleStack.push(.italic)
-            
-            let (_, textItems, textContentSize) = layoutTextItemWithString(attributedStringForRichText(text, styleStack: styleStack), boundingWidth: boundingWidth - horizontalInset * 2.0 - lineInset, offset: CGPoint(x: horizontalInset + lineInset, y: contentSize.height), media: media, webpage: webpage, fitToWidth: fitToWidth)
-            
-            contentSize.height += textContentSize.height
-            items.append(contentsOf: textItems)
-            
+
+            let innerBoundingWidth = boundingWidth - horizontalInset * 2.0 - lineInset
+            let innerHorizontalInset = horizontalInset + lineInset
+
+            if blocks.count == 1, case let .paragraph(text) = blocks[0] {
+                // Legacy single-paragraph fast path: italicized body (unchanged from prior behavior).
+                let styleStack = InstantPageTextStyleStack()
+                setupStyleStack(styleStack, theme: theme, category: .paragraph, link: false)
+                styleStack.push(.italic)
+
+                let (_, textItems, textContentSize) = layoutTextItemWithString(attributedStringForRichText(text, styleStack: styleStack), boundingWidth: innerBoundingWidth, offset: CGPoint(x: innerHorizontalInset, y: contentSize.height), media: media, webpage: webpage, fitToWidth: fitToWidth)
+
+                contentSize.height += textContentSize.height
+                items.append(contentsOf: textItems)
+            } else {
+                var previousChildItems: [InstantPageItem] = []
+                // Fixed, compact gap between a quote's child blocks (the full page-flow
+                // spacing around quotes is too airy when nested); the first child hugs
+                // the top (only verticalInset above it).
+                let childSpacing: CGFloat = 10.0
+                for (i, child) in blocks.enumerated() {
+                    let childLayout = layoutInstantPageBlock(webpage: webpage, userLocation: userLocation, rtl: rtl, block: child, boundingWidth: innerBoundingWidth, horizontalInset: innerHorizontalInset, safeInset: safeInset, isCover: false, previousItems: previousChildItems, fillToSize: nil, media: media, mediaIndexCounter: &mediaIndexCounter, embedIndexCounter: &embedIndexCounter, detailsIndexCounter: &detailsIndexCounter, theme: theme, strings: strings, dateTimeFormat: dateTimeFormat, webEmbedHeights: webEmbedHeights, cachedMessageSyntaxHighlight: cachedMessageSyntaxHighlight, excludeCaptions: excludeCaptions, isLast: i == blocks.count - 1 && isLast, fitToWidth: fitToWidth)
+                    let spacing: CGFloat = i == 0 ? 0.0 : childSpacing
+                    contentSize.height += spacing
+                    var childItems: [InstantPageItem] = []
+                    for var item in childLayout.items {
+                        item.frame = item.frame.offsetBy(dx: 0.0, dy: contentSize.height)
+                        childItems.append(item)
+                    }
+                    items.append(contentsOf: childItems)
+                    previousChildItems = childItems
+                    contentSize.height += childLayout.contentSize.height
+                }
+            }
+
             if case .empty = caption {
             } else {
                 contentSize.height += 14.0
-                
+
                 let styleStack = InstantPageTextStyleStack()
                 setupStyleStack(styleStack, theme: theme, category: .caption, link: false)
-                
-                let (_, captionItems, captionContentSize) = layoutTextItemWithString(attributedStringForRichText(caption, styleStack: styleStack), boundingWidth: boundingWidth - horizontalInset * 2.0 - lineInset, offset: CGPoint(x: horizontalInset + lineInset, y: contentSize.height), media: media, webpage: webpage)
-                
+
+                let (_, captionItems, captionContentSize) = layoutTextItemWithString(attributedStringForRichText(caption, styleStack: styleStack), boundingWidth: innerBoundingWidth, offset: CGPoint(x: innerHorizontalInset, y: contentSize.height), media: media, webpage: webpage)
+
                 contentSize.height += captionContentSize.height
                 items.append(contentsOf: captionItems)
             }
             contentSize.height += verticalInset
-            
+
             let shapeItem = InstantPageShapeItem(frame: CGRect(origin: CGPoint(x: horizontalInset, y: 0.0), size: CGSize(width: 3.0, height: contentSize.height)), shapeFrame: CGRect(origin: CGPoint(x: 0.0, y: 0.0), size: CGSize(width: 3.0, height: contentSize.height)), shape: .roundLine, color: theme.textCategories.paragraph.color)
-            
+
             items.append(shapeItem)
-            
+
             return InstantPageLayout(origin: CGPoint(), contentSize: contentSize, items: items)
         case let .pullQuote(text, caption):
             let verticalInset: CGFloat = 4.0

submodules/InstantPageUI/Sources/InstantPageV2Layout.swift

@@ -594,14 +594,14 @@ private func layoutBlock(
         return layoutCodeBlock(text, language: language, boundingWidth: boundingWidth,
                                horizontalInset: horizontalInset, context: &context)
 
-    case let .blockQuote(text, caption):
-        return layoutBlockQuote(text: text, caption: caption, isPull: false,
+    case let .blockQuote(blocks, caption):
+        return layoutBlockQuote(blocks: blocks, caption: caption,
                                 boundingWidth: boundingWidth, horizontalInset: horizontalInset,
-                                context: &context)
+                                isLast: isLast, context: &context)
     case let .pullQuote(text, caption):
-        return layoutBlockQuote(text: text, caption: caption, isPull: true,
-                                boundingWidth: boundingWidth, horizontalInset: horizontalInset,
-                                context: &context)
+        return layoutQuoteText(text: text, caption: caption, isPull: true,
+                               boundingWidth: boundingWidth, horizontalInset: horizontalInset,
+                               context: &context)
 
     case let .image(id, caption, url, webpageId):
         if case let .image(image) = context.media[id], let largest = largestImageRepresentation(image.representations) {
@@ -1901,6 +1901,86 @@ private func layoutCodeBlock(
 // MARK: - Block quote / pull quote layout (ported from V1 InstantPageLayout.swift lines 517–586)
 
 private func layoutBlockQuote(
+    blocks: [InstantPageBlock],
+    caption: RichText,
+    boundingWidth: CGFloat,
+    horizontalInset: CGFloat,
+    isLast: Bool,
+    context: inout LayoutContext
+) -> [InstantPageV2LaidOutItem] {
+    // Legacy single-paragraph fast path: preserve today's italicized body styling.
+    if blocks.count == 1, case let .paragraph(text) = blocks[0] {
+        return layoutQuoteText(text: text, caption: caption, isPull: false,
+                               boundingWidth: boundingWidth, horizontalInset: horizontalInset,
+                               context: &context)
+    }
+
+    let verticalInset: CGFloat = 4.0
+    let lineInset: CGFloat = 20.0
+    let barWidth: CGFloat = 3.0
+
+    let innerBoundingWidth = boundingWidth - horizontalInset * 2.0 - lineInset
+    let innerHorizontalInset = horizontalInset + lineInset
+
+    var result: [InstantPageV2LaidOutItem] = []
+    var contentHeight: CGFloat = verticalInset
+
+    // Fixed, compact gap between a quote's child blocks. The full page-flow spacing
+    // (spacingBetweenBlocks ~27pt around quotes) is too airy when nested; the first
+    // child hugs the top (only verticalInset above it).
+    let childSpacing: CGFloat = 10.0
+    for (i, child) in blocks.enumerated() {
+        let spacing: CGFloat = i == 0 ? 0.0 : childSpacing
+        let childItems = layoutBlock(
+            child,
+            boundingWidth: innerBoundingWidth,
+            horizontalInset: innerHorizontalInset,
+            isCover: false,
+            previousItems: result,
+            isLast: i == blocks.count - 1 && isLast,
+            context: &context
+        )
+        let dy = contentHeight + spacing
+        let offsetItems = childItems.map { $0.offsetBy(CGPoint(x: 0.0, y: dy)) }
+        let childMaxY = offsetItems.map { $0.frame.maxY }.max() ?? dy
+        contentHeight = max(contentHeight, childMaxY)
+        result.append(contentsOf: offsetItems)
+    }
+
+    // Optional caption (mirrors layoutQuoteText's caption branch).
+    if case .empty = caption {
+        // no caption
+    } else {
+        contentHeight += 14.0
+        let captionStyleStack = InstantPageTextStyleStack()
+        setupStyleStack(captionStyleStack, theme: context.theme, category: .caption, link: false)
+        let attributedCaption = attributedStringForRichText(caption, styleStack: captionStyleStack)
+        let (_, captionItems, captionSize) = layoutTextItem(
+            attributedCaption,
+            boundingWidth: innerBoundingWidth,
+            alignment: .natural,
+            offset: CGPoint(x: innerHorizontalInset, y: contentHeight),
+            fitToWidth: context.fitToWidth,
+            computeRevealCharacterRects: context.computeRevealCharacterRects
+        )
+        result.append(contentsOf: captionItems)
+        contentHeight += captionSize.height
+    }
+
+    contentHeight += verticalInset
+
+    // Vertical bar on the leading edge (matches the blockQuote branch of layoutQuoteText).
+    let bar = InstantPageV2BarItem(
+        frame: CGRect(x: horizontalInset, y: 0.0, width: barWidth, height: contentHeight),
+        color: context.theme.textCategories.paragraph.color,
+        cornerRadius: barWidth / 2.0
+    )
+    result.append(.blockQuoteBar(bar))
+
+    return result
+}
+
+private func layoutQuoteText(
     text: RichText,
     caption: RichText,
     isPull: Bool,

submodules/TelegramCore/FlatSerialization/Models/InstantPageBlock.fbs

@@ -91,8 +91,9 @@ table InstantPageBlock_List {
 }
 
 table InstantPageBlock_BlockQuote {
-    text:RichText (id: 0, required);
+    text:RichText (id: 0);
     caption:RichText (id: 1, required);
+    blocks:[InstantPageBlock] (id: 2);
 }
 
 table InstantPageBlock_PullQuote {

submodules/TelegramCore/Sources/ApiUtils/InstantPage.swift

@@ -246,7 +246,9 @@ extension InstantPageBlock {
                 self = .anchor(name)
             case let .pageBlockBlockquote(pageBlockBlockquoteData):
                 let (text, caption) = (pageBlockBlockquoteData.text, pageBlockBlockquoteData.caption)
-                self = .blockQuote(text: RichText(apiText: text), caption: RichText(apiText: caption))
+                self = .blockQuote(blocks: [.paragraph(RichText(apiText: text))], caption: RichText(apiText: caption))
+            case let .pageBlockBlockquoteBlocks(pageBlockBlockquoteBlocksData):
+                self = .blockQuote(blocks: pageBlockBlockquoteBlocksData.blocks.map { InstantPageBlock(apiBlock: $0) }, caption: RichText(apiText: pageBlockBlockquoteBlocksData.caption))
             case let .pageBlockPullquote(pageBlockPullquoteData):
                 let (text, caption) = (pageBlockPullquoteData.text, pageBlockPullquoteData.caption)
                 self = .pullQuote(text: RichText(apiText: text), caption: RichText(apiText: caption))
@@ -370,8 +372,14 @@ extension InstantPageBlock {
             } else {
                 return .pageBlockList(Api.PageBlock.Cons_pageBlockList(items: items.map { $0.apiInputPageListItem() }))
             }
-        case let .blockQuote(text, caption):
-            return .pageBlockBlockquote(Api.PageBlock.Cons_pageBlockBlockquote(text: text.apiRichText(), caption: caption.apiRichText()))
+        case let .blockQuote(blocks, caption):
+            if blocks.isEmpty {
+                return .pageBlockBlockquote(Api.PageBlock.Cons_pageBlockBlockquote(text: RichText.empty.apiRichText(), caption: caption.apiRichText()))
+            }
+            if blocks.count == 1, case let .paragraph(text) = blocks[0] {
+                return .pageBlockBlockquote(Api.PageBlock.Cons_pageBlockBlockquote(text: text.apiRichText(), caption: caption.apiRichText()))
+            }
+            return .pageBlockBlockquoteBlocks(Api.PageBlock.Cons_pageBlockBlockquoteBlocks(blocks: blocks.compactMap { $0.apiInputBlock() }, caption: caption.apiRichText()))
         case let .pullQuote(text, caption):
             return .pageBlockPullquote(Api.PageBlock.Cons_pageBlockPullquote(text: text.apiRichText(), caption: caption.apiRichText()))
         case let .image(id, caption, url, webpageId):

submodules/TelegramCore/Sources/SyncCore/SyncCore_InstantPage.swift

@@ -70,7 +70,7 @@ public indirect enum InstantPageBlock: PostboxCoding, Equatable {
     case divider
     case anchor(String)
     case list(items: [InstantPageListItem], ordered: Bool)
-    case blockQuote(text: RichText, caption: RichText)
+    case blockQuote(blocks: [InstantPageBlock], caption: RichText)
     case pullQuote(text: RichText, caption: RichText)
     case image(id: MediaId, caption: InstantPageCaption, url: String?, webpageId: MediaId?)
     case video(id: MediaId, caption: InstantPageCaption, autoplay: Bool, loop: Bool)
@@ -121,7 +121,13 @@ public indirect enum InstantPageBlock: PostboxCoding, Equatable {
             case InstantPageBlockType.list.rawValue:
                 self = .list(items: decodeListItems(decoder), ordered: decoder.decodeOptionalInt32ForKey("o") != 0)
             case InstantPageBlockType.blockQuote.rawValue:
-                self = .blockQuote(text: decoder.decodeObjectForKey("t", decoder: { RichText(decoder: $0) }) as! RichText, caption: decoder.decodeObjectForKey("c", decoder: { RichText(decoder: $0) }) as! RichText)
+                let caption = decoder.decodeObjectForKey("c", decoder: { RichText(decoder: $0) }) as! RichText
+                if let legacyText = decoder.decodeObjectForKey("t", decoder: { RichText(decoder: $0) }) as? RichText {
+                    self = .blockQuote(blocks: [.paragraph(legacyText)], caption: caption)
+                } else {
+                    let blocks: [InstantPageBlock] = decoder.decodeObjectArrayWithDecoderForKey("b")
+                    self = .blockQuote(blocks: blocks, caption: caption)
+                }
             case InstantPageBlockType.pullQuote.rawValue:
                 self = .pullQuote(text: decoder.decodeObjectForKey("t", decoder: { RichText(decoder: $0) }) as! RichText, caption: decoder.decodeObjectForKey("c", decoder: { RichText(decoder: $0) }) as! RichText)
             case InstantPageBlockType.image.rawValue:
@@ -225,9 +231,9 @@ public indirect enum InstantPageBlock: PostboxCoding, Equatable {
                 encoder.encodeInt32(InstantPageBlockType.list.rawValue, forKey: "r")
                 encoder.encodeObjectArray(items, forKey: "ml")
                 encoder.encodeInt32(ordered ? 1 : 0, forKey: "o")
-            case let .blockQuote(text, caption):
+            case let .blockQuote(blocks, caption):
                 encoder.encodeInt32(InstantPageBlockType.blockQuote.rawValue, forKey: "r")
-                encoder.encodeObject(text, forKey: "t")
+                encoder.encodeObjectArray(blocks, forKey: "b")
                 encoder.encodeObject(caption, forKey: "c")
             case let .pullQuote(text, caption):
                 encoder.encodeInt32(InstantPageBlockType.pullQuote.rawValue, forKey: "r")
@@ -445,8 +451,8 @@ public indirect enum InstantPageBlock: PostboxCoding, Equatable {
                 } else {
                     return false
                 }
-            case let .blockQuote(text, caption):
-                if case .blockQuote(text, caption) = rhs {
+            case let .blockQuote(lhsBlocks, lhsCaption):
+                if case let .blockQuote(rhsBlocks, rhsCaption) = rhs, lhsBlocks == rhsBlocks, lhsCaption == rhsCaption {
                     return true
                 } else {
                     return false
@@ -621,7 +627,15 @@ public indirect enum InstantPageBlock: PostboxCoding, Equatable {
             guard let value = flatBuffersObject.value(type: TelegramCore_InstantPageBlock_BlockQuote.self) else {
                 throw FlatBuffersError.missingRequiredField()
             }
-            self = .blockQuote(text: try RichText(flatBuffersObject: value.text), caption: try RichText(flatBuffersObject: value.caption))
+            let caption = try RichText(flatBuffersObject: value.caption)
+            if value.blocksCount > 0 {
+                let blocks = try (0 ..< value.blocksCount).map { try InstantPageBlock(flatBuffersObject: value.blocks(at: $0)!) }
+                self = .blockQuote(blocks: blocks, caption: caption)
+            } else if let legacyText = value.text {
+                self = .blockQuote(blocks: [.paragraph(try RichText(flatBuffersObject: legacyText))], caption: caption)
+            } else {
+                self = .blockQuote(blocks: [], caption: caption)
+            }
         case .instantpageblockPullquote:
             guard let value = flatBuffersObject.value(type: TelegramCore_InstantPageBlock_PullQuote.self) else {
                 throw FlatBuffersError.missingRequiredField()
@@ -796,12 +810,13 @@ public indirect enum InstantPageBlock: PostboxCoding, Equatable {
             TelegramCore_InstantPageBlock_List.addVectorOf(items: itemsOffset, &builder)
             TelegramCore_InstantPageBlock_List.add(ordered: ordered, &builder)
             offset = TelegramCore_InstantPageBlock_List.endInstantPageBlock_List(&builder, start: start)
-        case let .blockQuote(text, caption):
+        case let .blockQuote(blocks, caption):
             valueType = .instantpageblockBlockquote
-            let textOffset = text.encodeToFlatBuffers(builder: &builder)
+            let blocksOffsets = blocks.map { $0.encodeToFlatBuffers(builder: &builder) }
+            let blocksOffset = builder.createVector(ofOffsets: blocksOffsets, len: blocksOffsets.count)
             let captionOffset = caption.encodeToFlatBuffers(builder: &builder)
             let start = TelegramCore_InstantPageBlock_BlockQuote.startInstantPageBlock_BlockQuote(&builder)
-            TelegramCore_InstantPageBlock_BlockQuote.add(text: textOffset, &builder)
+            TelegramCore_InstantPageBlock_BlockQuote.addVectorOf(blocks: blocksOffset, &builder)
             TelegramCore_InstantPageBlock_BlockQuote.add(caption: captionOffset, &builder)
             offset = TelegramCore_InstantPageBlock_BlockQuote.endInstantPageBlock_BlockQuote(&builder, start: start)
         case let .pullQuote(text, caption):

submodules/TelegramStringFormatting/Sources/InstantPagePreviewText.swift

@@ -123,8 +123,9 @@ extension InstantPageBlock {
                 result.append(item.previewText())
             }
             return result
-        case let .blockQuote(text, caption):
-            return text.previewText() + caption.previewText()
+        case let .blockQuote(blocks, caption):
+            let body = blocks.map { $0.previewText() }.joined(separator: " ")
+            return body + caption.previewText()
         case let .pullQuote(text, caption):
             return text.previewText() + caption.previewText()
         case .image(_, _, _, _):