Add Markdown content to block configuration (#220)

* Add methods to access child content and render plain text

* Add the Markdown content to the block configuration

* Fix building with Swift 5.8

* Deprecate block-style methods with a label closure

* Fix deprecation warnings

* Update documentation

Author: gonzalezreal

Examples/Demo/Demo/HeadingsView.swift

@@ -25,8 +25,8 @@ struct HeadingsView: View {
       Section("Customization Example") {
         Markdown("# One Big Header")
       }
-      .markdownBlockStyle(\.heading1) { label in
-        label
+      .markdownBlockStyle(\.heading1) { configuration in
+        configuration.label
           .markdownMargin(top: .em(1), bottom: .em(1))
           .markdownTextStyle {
             FontFamily(.custom("Trebuchet MS"))

Examples/Demo/Demo/ImagesView.swift

@@ -43,8 +43,8 @@ struct ImagesView: View {
       Section("Customization Example") {
         Markdown(self.content)
       }
-      .markdownBlockStyle(\.image) { label in
-        label
+      .markdownBlockStyle(\.image) { configuration in
+        configuration.label
           .clipShape(RoundedRectangle(cornerRadius: 8))
           .shadow(radius: 8, y: 8)
           .markdownMargin(top: .em(1.6), bottom: .em(1.6))

Examples/Demo/Demo/QuotesView.swift

@@ -18,8 +18,8 @@ struct QuotesView: View {
       Section("Customization Example") {
         Markdown(self.content)
       }
-      .markdownBlockStyle(\.blockquote) { label in
-        label
+      .markdownBlockStyle(\.blockquote) { configuration in
+        configuration.label
           .padding()
           .markdownTextStyle {
             FontCapsVariant(.lowercaseSmallCaps)

README.md

@@ -226,13 +226,14 @@ extension Theme {
       ForegroundColor(.purple)
     }
     // More text styles...
-    .paragraph { label in
-      label
+    .paragraph { configuration in
+      configuration.label
         .relativeLineSpacing(.em(0.25))
         .markdownMargin(top: 0, bottom: 16)
     }
-    .listItem { label in
-      label.markdownMargin(top: .em(0.25))
+    .listItem { configuration in
+      configuration.label
+        .markdownMargin(top: .em(0.25))
     }
     // More block styles...
 }

Sources/MarkdownUI/DSL/Blocks/MarkdownContent.swift

@@ -60,13 +60,27 @@ public protocol MarkdownContentProtocol {
 /// }
 /// ```
 public struct MarkdownContent: Equatable, MarkdownContentProtocol {
+  /// Returns a Markdown content value with the sum of the contents of all the container blocks
+  /// present in this content.
+  ///
+  /// You can use this property to access the contents of a blockquote or a list. Returns `nil` if
+  /// there are no container blocks.
+  public var childContent: MarkdownContent? {
+    let children = self.blocks.map(\.children).flatMap { $0 }
+    return children.isEmpty ? nil : .init(blocks: children)
+  }
+
   public var _markdownContent: MarkdownContent { self }
   let blocks: [BlockNode]
 
   init(blocks: [BlockNode] = []) {
     self.blocks = blocks
   }
 
+  init(block: BlockNode) {
+    self.init(blocks: [block])
+  }
+
   init(_ components: [MarkdownContentProtocol]) {
     self.init(blocks: components.map(\._markdownContent).flatMap(\.blocks))
   }
@@ -88,4 +102,10 @@ public struct MarkdownContent: Equatable, MarkdownContentProtocol {
     let result = self.blocks.renderMarkdown()
     return result.hasSuffix("\n") ? String(result.dropLast()) : result
   }
+
+  /// Renders this Markdown content value as plain text.
+  public func renderPlainText() -> String {
+    let result = self.blocks.renderPlainText()
+    return result.hasSuffix("\n") ? String(result.dropLast()) : result
+  }
 }

Sources/MarkdownUI/Documentation.docc/Articles/GettingStarted.md

@@ -183,13 +183,14 @@ extension Theme {
       ForegroundColor(.purple)
     }
     // More text styles...
-    .paragraph { label in
-      label
+    .paragraph { configuration in
+      configuration.label
         .relativeLineSpacing(.em(0.25))
         .markdownMargin(top: 0, bottom: 16)
     }
-    .listItem { label in
-      label.markdownMargin(top: .em(0.25))
+    .listItem { configuration in
+      configuration.label
+        .markdownMargin(top: .em(0.25))
     }
     // More block styles...
 }

Sources/MarkdownUI/Parser/BlockNode.swift

@@ -14,6 +14,21 @@ enum BlockNode: Hashable {
 }
 
 extension BlockNode {
+  var children: [BlockNode] {
+    switch self {
+    case .blockquote(let children):
+      return children
+    case .bulletedList(_, let items):
+      return items.map(\.children).flatMap { $0 }
+    case .numberedList(_, _, let items):
+      return items.map(\.children).flatMap { $0 }
+    case .taskList(_, let items):
+      return items.map(\.children).flatMap { $0 }
+    default:
+      return []
+    }
+  }
+
   var isParagraph: Bool {
     guard case .paragraph = self else { return false }
     return true

Sources/MarkdownUI/Parser/MarkdownParser.swift

@@ -14,6 +14,12 @@ extension Array where Element == BlockNode {
       String(cString: cmark_render_commonmark(document, CMARK_OPT_DEFAULT, 0))
     } ?? ""
   }
+
+  func renderPlainText() -> String {
+    UnsafeNode.makeDocument(self) { document in
+      String(cString: cmark_render_plaintext(document, CMARK_OPT_DEFAULT, 0))
+    } ?? ""
+  }
 }
 
 extension BlockNode {

Sources/MarkdownUI/Theme/BlockStyle/BlockConfiguration.swift

@@ -15,23 +15,14 @@ public struct BlockConfiguration {
     public let body: AnyView
   }
 
-  /// The Markdown block content.
+  /// The Markdown block view.
   public let label: Label
-}
 
-extension BlockStyle where Configuration == BlockConfiguration {
-  /// Creates a block style that customizes a block by applying the given body.
-  /// - Parameter body: A view builder that returns the customized block.
-  public init<Body: View>(
-    @ViewBuilder body: @escaping (_ label: BlockConfiguration.Label) -> Body
-  ) {
-    self.init { configuration in
-      body(configuration.label)
-    }
-  }
-
-  /// Creates a block style that returns the block content without applying any customization.
-  public init() {
-    self.init { $0 }
-  }
+  /// The content of the Markdown block.
+  ///
+  /// This property provides access to different representations of the block content.
+  /// For example, you can use ``MarkdownContent/renderMarkdown()``
+  /// to get the Markdown formatted text or ``MarkdownContent/renderPlainText()``
+  /// to get the plain text of the block content.
+  public let content: MarkdownContent
 }

Sources/MarkdownUI/Theme/BlockStyle/TableCellConfiguration.swift

@@ -20,6 +20,9 @@ public struct TableCellConfiguration {
   /// The table cell column index.
   public let column: Int
 
-  /// The table cell content.
+  /// The table cell view.
   public let label: Label
+
+  /// The table cell content.
+  public let content: MarkdownContent
 }