Add code to highlight hashtags

brain-marks/AmplifyModelExtensions/AWSTweet+Extension.swift

@@ -17,3 +17,68 @@ extension AWSTweet: Hashable {
         hasher.combine(id)
     }
 }
+
+// swiftlint:disable line_length
+extension AWSTweet {
+    static let exampleAWSTweets = [
+        AWSTweet(
+            id: "5CA8E5FE-897B-4FF7-92FB-2F2B02770EA7",
+            tweetID: "1576773239132819457",
+            text: "@NutterFi #...RingsOfPower unlocked on my iPhone ? Gimme 😍",
+            timeStamp: "2022-10-03T03:16:49.000Z",
+            authorName: "yannemal",
+            authorUsername: "yannemal",
+            profileImageURL: "https://pbs.twimg.com/profile_images/605843886620045312/-tY5p18X_bigger.",
+            photosURL: nil,
+            category: nil,
+            userVerified: false),
+
+        AWSTweet(
+            id: "9A5E5628-734A-416A-AFE8-256CC6D1A135",
+            tweetID: "1579024778161102848",
+            text: "Learn iOS #..'; ';'#';' development for free:\n\nSwift → https://t.co/1OZPm0dlhv\nUIKit → https://t.co/gXZ2Wo36wI\n#SwiftUI → https://t.co/OihgZ73Gbs\nCombine → https://t.co/2nYyUPzIke\nVapor → https://t.co/HnThkQEsSn\nBackend → @supabase \niOS Newsletter → https://t.co/WpVbWdMvNf",
+            timeStamp: "2022-10-09T08:23:38.000Z",
+            authorName: "Mayank Gupta👨‍💻🥑",
+            authorUsername: "iosmayank",
+            profileImageURL: "https://pbs.twimg.com/profile_images/1515405040625745920/-qJQzUa5_bigger.jpg",
+            photosURL: nil,
+            category: nil,
+            userVerified: false),
+
+        AWSTweet(
+            id: "C477F2CF-3DCB-49F1-B77D-E6ED5528C8F1",
+            tweetID: "1579155290947485696",
+            text: "a few months ago i really started finding interest in computer vision. now i\'ve spent the past few weeks messing with ARKit and RealityKit, and having a lot#and#uoi$%#ask of fun!\n\na lot of separate \".generatePlane\" ModelEntity\'s + one USDZ file (field goal post) #RealityKit #ARKit #AR #SwiftUI https://t.co/vZ3H0t4bv6",
+            timeStamp: "2022-10-09T17:02:15.000Z",
+            authorName: "hunter ",
+            authorUsername: "hntrcodes",
+            profileImageURL: "https://pbs.twimg.com/profile_images/1577568264175091722/apKZEJrj_bigger.jpg",
+            photosURL: ["https://pbs.twimg.com/media/FepHGNtWYAIR2BI.jpg"],
+            category: nil,
+            userVerified: false),
+
+        AWSTweet(
+            id: "9C9B226D-24B4-45D4-9632-5A604A3E86AB",
+            tweetID: "1569916764326166534",
+            text: "Learn this new background task modifier for SwiftUI in my new #help... article! https://t.co/po8CExQhaY #apple #iOS #coding #Swift #SwiftUI",
+            timeStamp: "2022-09-14T05:11:38.000Z",
+            authorName: "Leonardo Pugliese",
+            authorUsername: "Leo_Pugliese",
+            profileImageURL: "https://pbs.twimg.com/profile_images/1243079749423038464/t50iTav1_bigger.jpg",
+            photosURL: nil,
+            category: nil,
+            userVerified: false),
+
+        AWSTweet(
+            id: "047EF8B3-F2BF-4BAC-9AF5-EC515901ACED",
+            tweetID: "1579740738140897280",
+            text: "I finally reached €4k MRR. 🥳\n\nI switched my apps to subscriptions 2 years ago. Before, I usually made around €1k a month (paid upfront).\n\nNow they pay my bills, and I can focus 100% on growing them even further. 🤗\n\n#buildinpublic https://t.co/o4u9EHAg7I",
+            timeStamp: "2022-10-11T07:48:36.000Z",
+            authorName: "Florian Mielke",
+            authorUsername: "FlorianMielke",
+            profileImageURL: "https://pbs.twimg.com/profile_images/1509431457634213891/4rokDzVd_bigger.jpg", photosURL: ["https://pbs.twimg.com/media/FexcLs7WQAUIoKt.jpg"],
+            category: nil,
+            userVerified: false)
+    ]
+}
+

brain-marks/Tweets/Views/TweetCard.swift

@@ -46,7 +46,7 @@ struct TweetHeaderView: View {
 struct TweetBodyView: View {
     let tweetBody: String
     var body: some View {
-        Text(tweetBody)
+        TextHighlightingHashtags(tweetBody)
             .font(.body)
             .lineSpacing(8.0)
             .padding(EdgeInsets(top: 0, leading: 18, bottom: 18, trailing: 18))
@@ -167,9 +167,73 @@ struct TimeStampView: View {
     }
 }
 
+// swiftlint:disable shorthand_operator
+private extension TweetBodyView {
+
+    /// Use this Text View to highlight and #s in tweets following Twitter's hashtag rules.
+    /// Only alphanumeric characters directly after a # symbol will be highlighted.
+    /// Any other symbols before or after a # will not be highlighted.
+    /// - Parameter tweet: The string to have occurances of hashtags highlighted.
+    /// - Returns: A text view where words preceeded by "#" are highlighted.
+    func TextHighlightingHashtags(_ tweet: String) -> Text {
+
+        guard tweet.contains("#") else { return Text(tweet) }
+
+        var output = Text("")
+        let words = tweet.split(separator: " ")
+
+        for word in words {
+            if let hashtagIndex = word.firstIndex(of: "#") {
+
+                // Avoid highlighting the first part of a word preceeding a #
+                let prefixString = word.prefix(upTo: hashtagIndex)
+                output = output + Text(" ") + Text(prefixString)
+
+                let hashtagIndexPlusOne = word.index(hashtagIndex,
+                                                     offsetBy: 1)
+                let hashtagPlusSuffixString = word.suffix(
+                    from: hashtagIndexPlusOne)
+
+                if let suffixIndex = hashtagPlusSuffixString.firstIndex(
+                    where: {!$0.isNumber && !$0.isLetter}) {
+                    // If the # word is followed by non-alphanumeric symbols do not highlight the symbols
+                    let hashtagString = hashtagPlusSuffixString.prefix(
+                        upTo: suffixIndex)
+
+                    if hashtagString.count < 1 {
+                        // If # is on its own or followed by symbols do not highlight.
+                        output = output + Text("#")
+                    } else {
+                        let hashtagText = Text("#" + hashtagString)
+                            .foregroundColor(Color("twitter"))
+                        output = output + hashtagText
+                    }
+
+                    let suffixString = hashtagPlusSuffixString[suffixIndex...]
+                    output = output + Text(suffixString)
+
+                } else {
+                    // If there are no symbols at the end of a string highlight the whole string after the #
+                    output = output + Text("#" + hashtagPlusSuffixString).foregroundColor(Color("twitter"))
+                }
+            } else {
+                // If word does not contain # do not highlight
+                output = output + Text(" ") + Text(String(word))
+            }
+        }
+        return output
+    }
+}
+
 struct TweetCard_Previews: PreviewProvider {
     static var previews: some View {
-        TweetCard(tweet: AWSTweet(id: "123", tweetID: "234", text: "Tweet ext here"))
-            .previewLayout(PreviewLayout.sizeThatFits)
+        Group {
+            TweetCard(tweet: AWSTweet.exampleAWSTweets[0])
+            TweetCard(tweet: AWSTweet.exampleAWSTweets[1])
+            TweetCard(tweet: AWSTweet.exampleAWSTweets[2])
+            TweetCard(tweet: AWSTweet.exampleAWSTweets[3])
+            TweetCard(tweet: AWSTweet.exampleAWSTweets[4])
+        }
+        .previewLayout(PreviewLayout.sizeThatFits)
     }
 }