Add control of ParagraphSpacingPolicy to remove additional line breaks

README.md

@@ -268,6 +268,29 @@ To extend the tag name and customize its style, you can use the ExtendTagName cl
 let parser = ZHTMLParserBuilder.initWithDefault().add(ExtendTagName("zhgchgli"), withCustomStyle: MarkupStyle(backgroundColor: MarkupStyleColor(name: .aquamarine))).build()
 ```
 
+#### Paragraph Spacing Policy
+
+Often, you will want to create some type of spacing between various paragraphs or elements to increase legibility. There are two strategies to handle this:
+
+1. Create additional line breaks in between paragraphs and sections. This means that there will be the size of 1 empty paragraph between each other paragraph. This is the default behaviour. In this mode you will likely want to ensure you are ***Not*** using paragraph spacing in in your markup styles.
+2. Make use of `paragraphSpacing` through `MarkupStyleParagraphStyle` or `NSParagraphStyle`. If you are using these you will likely want to disable the additional line breaks.
+
+This can be configured on your your `ZHTMLParserBuilder` as follows:
+
+```swift
+let parser = ZHTMLParserBuilder
+    .initWithDefault()
+    // Indicate that we should use paragraph spacing for spacing.
+    .set(spacingPolicy: .paragraphSpacing)
+    // Create our spacing using paragraphSpacing.
+    .set(rootStyle: .init(
+        paragraphStyle: .init(
+            paragraphSpacing: 12
+        )
+    ))
+    .build()
+```
+
 ### Render HTML String
 ```swift
 parser.render(htmlString) // NSAttributedString

Sources/ZMarkupParser/Core/Processor/MarkupNSAttributedStringVisitor.swift

@@ -13,6 +13,7 @@ struct MarkupNSAttributedStringVisitor: MarkupVisitor {
 
     let components: [MarkupStyleComponent]
     let rootStyle: MarkupStyle?
+    var paragraphSpacingPolicy: ParagraphSpacingPolicy = .lineBreaks
 
     func visit(_ markup: RootMarkup) -> Result {
         return reduceBreaklineInResultNSAttributedString(collectAttributedString(markup))
@@ -82,14 +83,18 @@ struct MarkupNSAttributedStringVisitor: MarkupVisitor {
 
     func visit(_ markup: ListMarkup) -> Result {
         let attributedString = collectAttributedString(markup)
-        attributedString.append(makeBreakLine(in: markup))
+        if paragraphSpacingPolicy == .lineBreaks {
+            attributedString.append(makeBreakLine(in: markup))
+        }
         attributedString.insert(makeBreakLine(in: markup), at: 0)
         return attributedString
     }
 
     func visit(_ markup: ParagraphMarkup) -> Result {
         let attributedString = collectAttributedString(markup)
-        attributedString.append(makeBreakLine(in: markup, reduceable: false))
+        if paragraphSpacingPolicy == .lineBreaks {
+            attributedString.append(makeBreakLine(in: markup, reduceable: false))
+        }
         attributedString.insert(makeBreakLine(in: markup, reduceable: false), at: 0)
         return attributedString
     }
@@ -143,14 +148,18 @@ struct MarkupNSAttributedStringVisitor: MarkupVisitor {
 
     func visit(_ markup: TableMarkup) -> Result {
         let attributedString = collectAttributedString(markup)
-        attributedString.append(makeBreakLine(in: markup))
+        if paragraphSpacingPolicy == .lineBreaks {
+            attributedString.append(makeBreakLine(in: markup))
+        }
         attributedString.insert(makeBreakLine(in: markup), at: 0)
         return attributedString
     }
 
     func visit(_ markup: HeadMarkup) -> NSAttributedString {
         let attributedString = collectAttributedString(markup)
-        attributedString.append(makeBreakLine(in: markup))
+        if paragraphSpacingPolicy == .lineBreaks {
+            attributedString.append(makeBreakLine(in: markup))
+        }
         attributedString.insert(makeBreakLine(in: markup), at: 0)
         return attributedString
     }
@@ -163,7 +172,9 @@ struct MarkupNSAttributedStringVisitor: MarkupVisitor {
 
     func visit(_ markup: BlockQuoteMarkup) -> NSAttributedString {
         let attributedString = collectAttributedString(markup)
-        attributedString.append(makeBreakLine(in: markup))
+        if paragraphSpacingPolicy == .lineBreaks {
+            attributedString.append(makeBreakLine(in: markup))
+        }
         attributedString.insert(makeBreakLine(in: markup), at: 0)
         return attributedString
     }

Sources/ZMarkupParser/Core/Processor/MarkupRenderProcessor.swift

@@ -7,17 +7,46 @@
 
 import Foundation
 
+public enum ParagraphSpacingPolicy {
+    ///
+    /// In this mode, line break will be used to create spacing between paragraphs
+    ///
+    /// For example
+    /// Line 1
+    ///
+    /// Line 2
+    case lineBreaks
+    ///
+    /// In this mode new additional line breaks are added.
+    ///
+    /// Instead the MarkupStyleParagraphStyle.paragraphSpacing will create spacing between paragraphs.
+    ///
+    /// For example
+    /// Line 1
+    /// Line 2
+    ///
+    case paragraphSpacing
+}
+
+
 final class MarkupRenderProcessor: ParserProcessor {
     typealias From = (Markup, [MarkupStyleComponent])
     typealias To = NSAttributedString
 
     let rootStyle: MarkupStyle?
-    init(rootStyle: MarkupStyle?) {
+    let paragraphSpacingPolicy: ParagraphSpacingPolicy
+
+    init(rootStyle: MarkupStyle?, paragraphSpacingPolicy: ParagraphSpacingPolicy = .lineBreaks) {
         self.rootStyle = rootStyle
+        self.paragraphSpacingPolicy = paragraphSpacingPolicy
     }
 
     func process(from: From) -> To {
-        let visitor = MarkupNSAttributedStringVisitor(components: from.1, rootStyle: rootStyle)
+        let visitor = MarkupNSAttributedStringVisitor(
+            components: from.1,
+            rootStyle: rootStyle,
+            paragraphSpacingPolicy: paragraphSpacingPolicy
+        )
         return visitor.visit(markup: from.0)
     }
 }

Sources/ZMarkupParser/HTML/ZHTMLParser.swift

@@ -20,12 +20,18 @@ public final class ZHTMLParser {
     lazy var htmlStringToParsedResult: HTMLStringToParsedResultProcessor = HTMLStringToParsedResultProcessor()
     lazy var markupStripperProcessor: MarkupStripperProcessor = MarkupStripperProcessor()
 
-    init(htmlTags: [HTMLTag], styleAttributes: [HTMLTagStyleAttribute], policy: MarkupStylePolicy, rootStyle: MarkupStyle?) {
+    init(
+        htmlTags: [HTMLTag],
+        styleAttributes: [HTMLTagStyleAttribute],
+        policy: MarkupStylePolicy,
+        rootStyle: MarkupStyle?,
+        paragraphSpacingPolicy: ParagraphSpacingPolicy = .lineBreaks
+    ) {
         self.htmlTags = htmlTags
         self.styleAttributes = styleAttributes
         self.rootStyle = rootStyle
 
-        self.markupRenderProcessor = MarkupRenderProcessor(rootStyle: rootStyle)
+        self.markupRenderProcessor = MarkupRenderProcessor(rootStyle: rootStyle, paragraphSpacingPolicy: paragraphSpacingPolicy)
 
         self.htmlParsedResultToHTMLElementWithRootMarkupProcessor = HTMLParsedResultToHTMLElementWithRootMarkupProcessor(htmlTags: htmlTags)
         self.htmlElementWithMarkupToMarkupStyleProcessor = HTMLElementWithMarkupToMarkupStyleProcessor(styleAttributes: styleAttributes, policy: policy)

Sources/ZMarkupParser/HTML/ZHTMLParserBuilder.swift

@@ -13,6 +13,7 @@ public final class ZHTMLParserBuilder {
     private(set) var styleAttributes: [HTMLTagStyleAttribute] = []
     private(set) var rootStyle: MarkupStyle? = .default
     private(set) var policy: MarkupStylePolicy = .respectMarkupStyleFromHTMLStyleAttribute
+    private(set) var paragraphSpacingPolicy: ParagraphSpacingPolicy = .lineBreaks
 
     public init() {
 
@@ -63,7 +64,18 @@ public final class ZHTMLParserBuilder {
         return self
     }
 
+    public func set(spacingPolicy: ParagraphSpacingPolicy) -> Self {
+        self.paragraphSpacingPolicy = spacingPolicy
+        return self
+    }
+
     public func build() -> ZHTMLParser {
-        return ZHTMLParser(htmlTags: htmlTags, styleAttributes: styleAttributes, policy: policy, rootStyle: rootStyle)
+        return ZHTMLParser(
+            htmlTags: htmlTags,
+            styleAttributes: styleAttributes,
+            policy: policy,
+            rootStyle: rootStyle,
+            paragraphSpacingPolicy: paragraphSpacingPolicy
+        )
     }
 }