Merge pull request #121 from writeas/use-content-if-post-has-no-title

Use content if post has no title

Shared/PostList/PostCellView.swift

@@ -1,6 +1,7 @@
 import SwiftUI
 
 struct PostCellView: View {
+    @EnvironmentObject var model: WriteFreelyModel
     @ObservedObject var post: WFAPost
     var collectionName: String?
 
@@ -12,6 +13,13 @@ struct PostCellView: View {
         return formatter
     }()
 
+    var titleText: String {
+        if post.title.isEmpty {
+            return model.posts.getBodyPreview(of: post)
+        }
+        return post.title
+    }
+
     var body: some View {
         HStack {
             VStack(alignment: .leading) {
@@ -22,7 +30,7 @@ struct PostCellView: View {
                         .padding(EdgeInsets(top: 3, leading: 4, bottom: 3, trailing: 4))
                         .overlay(RoundedRectangle(cornerRadius: 2).stroke(Color.secondary, lineWidth: 1))
                 }
-                Text(post.title)
+                Text(titleText)
                     .font(.headline)
                 Text(post.createdDate ?? Date(), formatter: Self.createdDateFormat)
                     .font(.caption)
@@ -62,3 +70,17 @@ struct PostCell_NormalPreviews: PreviewProvider {
             .environment(\.managedObjectContext, context)
     }
 }
+
+struct PostCell_NoTitlePreviews: PreviewProvider {
+    static var previews: some View {
+        let context = LocalStorageManager.persistentContainer.viewContext
+        let testPost = WFAPost(context: context)
+        testPost.title = ""
+        testPost.body = "Here's some cool sample body text."
+        testPost.collectionAlias = "My Cool Blog"
+        testPost.createdDate = Date()
+
+        return PostCellView(post: testPost)
+            .environment(\.managedObjectContext, context)
+    }
+}

Shared/PostList/PostListModel.swift

@@ -18,4 +18,107 @@ class PostListModel: ObservableObject {
             print("Error: Failed to purge cached posts.")
         }
     }
+
+    func getBodyPreview(of post: WFAPost) -> String {
+        var elidedPostBody: String = ""
+
+        // Strip any markdown from the post body.
+        let strippedPostBody = stripMarkdown(from: post.body)
+
+        // Extract lede from post.
+         elidedPostBody = extractLede(from: strippedPostBody)
+
+        return elidedPostBody
+    }
+}
+
+private extension PostListModel {
+
+    func stripMarkdown(from string: String) -> String {
+        var strippedString = string
+        strippedString = stripHeadingOctothorpes(from: strippedString)
+        strippedString = stripImages(from: strippedString, keepAltText: true)
+        return strippedString
+    }
+
+    func stripHeadingOctothorpes(from string: String) -> String {
+        let newLines = CharacterSet.newlines
+        var processedComponents: [String] = []
+        let components = string.components(separatedBy: newLines)
+        for component in components {
+            if component.isEmpty {
+                continue
+            }
+            var newString = component
+            while newString.first == "#" {
+                newString.removeFirst()
+            }
+            if newString.hasPrefix(" ") {
+                newString.removeFirst()
+            }
+            processedComponents.append(newString)
+        }
+        let headinglessString = processedComponents.joined(separator: "\n\n")
+        return headinglessString
+    }
+
+    func stripImages(from string: String, keepAltText: Bool = false) -> String {
+        let pattern = #"!\[[\"]?(.*?)[\"|]?\]\(.*?\)"#
+        var processedComponents: [String] = []
+        let components = string.components(separatedBy: .newlines)
+        for component in components {
+            if component.isEmpty { continue }
+            var processedString: String = component
+            if keepAltText {
+                let regex = try? NSRegularExpression(pattern: pattern, options: [])
+                if let matches = regex?.matches(
+                    in: component, options: [], range: NSRange(location: 0, length: component.utf16.count)
+                ) {
+                    for match in matches {
+                        if let range = Range(match.range(at: 1), in: component) {
+                            processedString = "\(component[range])"
+                        }
+                    }
+                }
+            } else {
+                let range = component.startIndex..<component.endIndex
+                processedString = component.replacingOccurrences(
+                    of: pattern,
+                    with: "",
+                    options: .regularExpression,
+                    range: range
+                )
+            }
+            if processedString.isEmpty { continue }
+            processedComponents.append(processedString)
+        }
+        return processedComponents.joined(separator: "\n\n")
+    }
+
+    func extractLede(from string: String) -> String {
+        let truncatedString = string.prefix(80)
+        let terminatingPunctuation = ".。?"
+        let terminatingCharacters = CharacterSet(charactersIn: terminatingPunctuation).union(.newlines)
+
+        var lede: String = ""
+        let sentences = truncatedString.components(separatedBy: terminatingCharacters)
+        if let firstSentence = (sentences.filter { !$0.isEmpty }).first {
+            if truncatedString.count > firstSentence.count {
+                if terminatingPunctuation.contains(truncatedString[firstSentence.endIndex]) {
+                    lede = String(truncatedString[...firstSentence.endIndex])
+                } else {
+                    lede = firstSentence
+                }
+            } else if truncatedString.count == firstSentence.count {
+                if string.count > 80 {
+                    if let endOfStringIndex = truncatedString.lastIndex(of: " ") {
+                        lede = truncatedString[..<endOfStringIndex] + "…"
+                    }
+                } else {
+                    lede = firstSentence
+                }
+            }
+        }
+        return lede
+    }
 }