RichTextSections

A lightweight Swift library for building rich NSAttributedString from composable sections and inline items — ready to drop into any UITextView.

Features

• Section-based layout — each section renders as a single line, items flow inline
• Rich inline items — text, bold, italic, strikethrough, images, HTML, and tappable links
• Per-item overrides — customize font, size, and color on individual items
• Per-section paragraph style — alignment, indentation, and line spacing per section
• Reusable configuration — define RTBuilderConfiguration once, share across builders
• Tappable links — built-in handler support with or without a URL
• Inline images — embed icons and badges via NSTextAttachment, auto-aligned to text

Requirements

• iOS 13.0+
• Swift 5.0+

Installation

Swift Package Manager

dependencies: [
    .package(url: "https://github.com/yourname/RichTextSections.git", from: "1.0.0")
]

Manual

Copy the Sources folder into your project.

Quick Start

let result = RTBuilder()
    .font(.systemFont(ofSize: 14))
    .color(.white)
    .section {
        $0.text("Hello ")
          .bold("World")
    }
    .build()

textView.attributedText = result.attributedString

Usage

Core Concept

A section is a single line. Each section contains one or more items that render inline. Sections are separated by automatic line breaks:

RTBuilder()
    .section {                        // Line 1: ⭐ Welcome
        $0.image(starIcon)
          .text(" ")
          .bold("Welcome")
    }
    .section {                        // Line 2: Visit the Docs now.
        $0.text("Visit the ")
          .link("Docs", url: docsURL)
          .text(" now.")
    }
    .spacing()                        // Blank line
    .section {                        // Line 3: Last updated: 2026
        $0.italic("Last updated: 2026", size: 12, color: .gray)
    }
    .build()

Items

Item	Description
.text	Plain text with optional font and color override
.bold	Bold text with optional size and color override
.italic	Italic text with optional size and color override
.strikethrough	Strikethrough text with optional size and color override
.image	Inline image with optional size
.html	HTML string with optional inline styles
.link	Tappable link with optional URL and tap handler

Strikethrough

Useful for showing old prices, deprecated info, or corrections:

.section {
    $0.text("Price: ")
      .strikethrough("$9.99", color: .systemRed)
      .text(" ")
      .bold("$4.99", color: .systemGreen)
      .text(" (50% off!)")
}

Section Style

Each section can have its own paragraph style via RTSectionStyle. When not provided, the builder's global alignment and line spacing are used:

// Left-aligned with indent
.section(style: RTSectionStyle(alignment: .left, indent: 24)) {
    $0.bold("Note: ", color: .systemOrange)
      .text("This section is indented 24pt from the left.")
}

// Right-aligned signature
.section(style: RTSectionStyle(alignment: .right)) {
    $0.italic("— The Author", size: 12, color: .gray)
}

// First-line indent for paragraph style
.section(style: RTSectionStyle(alignment: .left, firstLineIndent: 32)) {
    $0.text("The first line starts further in while subsequent lines wrap normally.")
}

Available properties on RTSectionStyle:

Property	Description	Default
alignment	Text alignment override	Global
indent	Head indent (left margin)	0
firstLineIndent	First-line head indent	0
tailIndent	Tail indent (negative = inset from right)	0
lineSpacing	Line spacing override	Global

Global Style

RTBuilder()
    .font(.systemFont(ofSize: 14))   // base font
    .color(.white)                    // base text color
    .alignment(.center)              // paragraph alignment
    .lineSpacing(4)                  // line spacing
    .linkColor(.systemBlue)          // link color
    .linkUnderline(true)             // underline links

Reusable Configuration

Define a shared configuration to keep styling consistent:

let config = RTBuilderConfiguration(
    font: .systemFont(ofSize: 14),
    color: .white,
    alignment: .center,
    lineSpacing: 4,
    linkColor: .systemBlue
)

// Reuse across builders
let message1 = RTBuilder(config: config)
    .section { $0.text("First message") }
    .build()

let message2 = RTBuilder(config: config)
    .section { $0.bold("Second message") }
    .build()

Override per builder when needed:

RTBuilder(config: config)
    .color(.gray)
    .section { $0.text("Muted message") }
    .build()

Link Handling

RTResult provides linkHandlers and linkTextMap for use in UITextViewDelegate:

class ViewController: UIViewController, UITextViewDelegate {
    
    private var linkResult: RTResult?
    
    func setup() {
        let result = RTBuilder()
            .section {
                $0.text("Read the ")
                  .link("Terms", url: termsURL) { text, url in
                      // handle tap
                  }
            }
            .section {
                $0.link("Contact") { text, _ in
                    // link without URL — custom action
                }
            }
            .build()
        
        linkResult = result
        textView.attributedText = result.attributedString
        textView.delegate = self
    }
    
    func textView(_ textView: UITextView,
                  shouldInteractWith URL: URL,
                  in characterRange: NSRange,
                  interaction: UITextItemInteraction) -> Bool {
        if let handler = linkResult?.linkHandlers[URL],
           let info = linkResult?.linkTextMap[URL] {
            handler(info.text, info.originalURL)
        }
        return false
    }
}

HTML Styles

Apply inline CSS to .html items:

.section {
    $0.html("<b>Bold</b> and <i>italic</i>", styles: [
        .font(.systemFont(ofSize: 14)),
        .size(14),
        .color("#FF0000")
    ])
}

Project Structure

Sources/
├── Enum/
│   ├── RTSection.swift              // Section enum (items or spacing)
│   ├── RTItem.swift                 // Inline content unit
│   └── RTHTMLStyle.swift            // HTML inline styles
├── RTBuilder.swift                  // Main builder class
├── RTBuilderConfiguration.swift     // Reusable style config
├── RTItemBuilder.swift              // Builder for items within a section
├── RTResult.swift                   // Build output
└── RTSectionStyle.swift             // Per-section paragraph style

Demo/
└── ViewController.swift             // Usage example

License

MIT License. See LICENSE for details.