Add option to replace last empty lines by another special character.

Author: SergioEstevao

Aztec/Classes/NSAttributedString/Conversions/HTMLConverter.swift

@@ -20,7 +20,11 @@ public class HTMLConverter {
     }
 
     // MARK: - Converters: HTML -> AttributedString
-    
+
+    /// If a value is set the character set will be used to replace any last empty line created by the converter.
+    ///
+    open var characterToReplaceLastEmtpyLine: Character?
+
     let htmlToTree = HTMLParser()
 
     private(set) lazy var treeToAttributedString: AttributedStringSerializer = {
@@ -54,11 +58,27 @@ public class HTMLConverter {
         pluginManager.process(htmlTree: rootNode)
 
         let defaultAttributes = defaultAttributes ?? [:]
-        let attributedString = treeToAttributedString.serialize(rootNode, defaultAttributes: defaultAttributes)
+        var attributedString = treeToAttributedString.serialize(rootNode, defaultAttributes: defaultAttributes)
+
+        if let characterToUse = characterToReplaceLastEmtpyLine {
+            attributedString = replaceLastEmptyLine(in: attributedString, with: characterToUse)
+        }
 
         return attributedString
     }
 
+    func replaceLastEmptyLine(in attributedString: NSAttributedString, with replacement: Character) -> NSAttributedString {
+        var result = attributedString
+        let string = attributedString.string
+        if string.isEmptyLineAtEndOfFile(at: string.count), !string.isEmpty, let location = string.location(before: attributedString.length) {
+            let mutableString = NSMutableAttributedString(attributedString: attributedString)
+            let attributes = mutableString.attributes(at: location, effectiveRange: nil)
+            mutableString.replaceCharacters(in: NSRange(location: location, length: attributedString.length-location), with: NSAttributedString(string: String(replacement), attributes: attributes))
+            result = mutableString
+        }
+        return result
+    }
+
 
     /// Check if the given html string is supported to be parsed into Attributed Strings.
     ///

AztecTests/TextKit/TextStorageTests.swift

@@ -494,4 +494,26 @@ class TextStorageTests: XCTestCase {
 
         XCTAssertEqual(expectedResult, result)
     }
+
+    func testEmptyListOutput() {
+        let initialHTML = "<ul><li></li></ul>"
+
+        // Setup
+        let defaultAttributes: [NSAttributedString.Key: Any] = [.font: UIFont.systemFont(ofSize: 14),
+                                                                .paragraphStyle: ParagraphStyle.default]
+
+        storage.setHTML(initialHTML, defaultAttributes: defaultAttributes)
+        var expectedResult = String(.paragraphSeparator)
+        var result = String(storage.string)
+
+        XCTAssertEqual(expectedResult, result)
+
+        storage.htmlConverter.characterToReplaceLastEmtpyLine = Character(.zeroWidthSpace)
+
+        storage.setHTML(initialHTML, defaultAttributes: defaultAttributes)
+        expectedResult = String(.zeroWidthSpace)
+        result = String(storage.string)
+
+        XCTAssertEqual(expectedResult, result)
+    }
 }