WKDevKit

A lightweight developer toolkit for inspecting WKWebView internals — built for SwiftUI. Explore localStorage, sessionStorage, cookies, and the live DOM tree, right inside your iOS app.

⚠️ Disclaimer: Still in Development

Heads up! WKDevKit is under active development. APIs, data models, and behaviors may change without notice as features stabilize.

We welcome issues, pull requests, and feedback — but please don’t rely on a stable public API just yet. Breaking changes are likely as the project evolves.

Features

Debug Panel

The embedded WebView includes a comprehensive Debug Panel accessible via the Debug button in the navigation bar. The panel provides three main tabs:

1. Console Tab

Real-time JavaScript console logging with:

• Captured Methods: console.log, console.warn, console.error, console.info, console.debug
• Visual Indicators:
  • Color-coded messages (error=red, warn=orange, info=blue, debug=purple, log=default)
  • Icons for each log type
  • Timestamps for each message
• Features:
  • Auto-scroll to latest log
  • Clear button to remove all logs
  • Selectable text for copying log messages

2. DOM Inspector Tab

Interactive DOM tree visualization with multiple view modes:

Tree View Mode

• Hierarchical Display: Expandable/collapsible DOM nodes
• Element Information:
  • Tag names with IDs and classes (e.g., div#header.nav-bar)
  • Inner text content preview (truncated to 50 chars)
  • Child count indicators
• Search Functionality:
  • Filters nodes by tag, ID, class, or text content
  • Highlights matching text in yellow
  • Shows filtered vs total child count
  • Requires 2+ characters to activate

Raw Text Mode

• HTML Output: Properly formatted and indented HTML
• Text Content: Includes innerText from elements
• Search Functionality:
  • Highlights all occurrences in yellow
  • Case-insensitive matching
  • Fully selectable text for copying

Floating Action Buttons (FABs)

• Search FAB (top-right, orange): Toggle search input field
• Tree View FAB (bottom-right): Switch to hierarchical tree view
• Raw Text FAB (bottom-right): Switch to HTML text view

3. Web Storage Tab

Comprehensive web storage inspection with automatic loading:

• Local Storage: Key-value pairs stored in localStorage
• Session Storage: Temporary session-based storage items
• Cookies: Document cookies with key-value parsing
• Features:
  • Organized by storage type with section headers
  • Item count display for each section
  • Expandable long values (100+ characters)
  • Auto-refresh when tab becomes visible
  • Selectable text for copying

4. Info Tab

Displays current page information:

• Current URL with selectable text
• Clean, readable format

Technical Implementation

JavaScript Injection

The WebView injects custom JavaScript to:

1. Console Override: Intercepts console methods and forwards to native code
2. DOM Extraction: Recursively traverses DOM tree to capture structure and content
3. Storage Access: Extracts localStorage, sessionStorage, and document cookies

Native Components

• WKWebView Configuration: Custom message handlers for JavaScript communication
• SwiftUI Integration: Modern declarative UI with proper state management
• Thread Safety: Uses @MainActor for safe WebView JavaScript evaluation

Architecture

Project Structure

InAppWebViewInspector/
├── ContentView.swift           # Main view with WebView type picker
├── EmbeddedWebView/
│   ├── WebView.swift           # WKWebView wrapper with console/DOM/storage capabilities
│   ├── EmbeddedWebViewScreen.swift # Container screen
│   ├── DebugPanel.swift        # Debug panel with navigation
│   ├── DebugTabView.swift      # Tabbed debugging interface
│   ├── WebStorageView.swift    # Web storage inspection
│   └── InfoView.swift          # Page information display
├── Item.swift                  # SwiftData model
└── InAppWebViewInspectorApp.swift # App entry point

Key Components

EmbeddedWebView/WebView.swift

• ConsoleMessage: Struct for console log data
• WebStorageItem: Struct for storage data (localStorage, sessionStorage, cookies)
• WebStorageType: Enum for storage type classification
• DOMNode: Decodable struct for DOM tree representation
• WebViewModel: Manages WebView reference and data fetching
• ConsoleMessageHandler: WKScriptMessageHandler for console logs
• WebView: UIViewRepresentable wrapper for WKWebView

EmbeddedWebView/DebugPanel.swift

• DebugPanel: Main debug panel with navigation and state management

EmbeddedWebView/DebugTabView.swift

• DebugTabView: Tabbed interface for debugging tools

EmbeddedWebView/WebStorageView.swift

• WebStorageView: Storage inspection with sectioned display
• WebStorageSection: Section headers for different storage types
• WebStorageItemRow: Individual storage item display

EmbeddedWebView/InfoView.swift

• InfoView: Current page information display

Additional Views

• ConsoleView: Console log display with auto-scroll
• ConsoleLogRow: Individual console message display
• DOMInspectorView: DOM tree/raw view with search and FABs
• DOMNodeView: Recursive tree node display with search highlighting

Requirements

• iOS 18.5+
• Xcode 15.0+
• Swift 5.0+

Building

1. Open ExampleApp.xcodeproj in Xcode
2. Select your target device or simulator
3. Build and run (Cmd+R)

Screenshots

DOM Inspector

The DOM Inspector provides both tree view and raw HTML modes with powerful search capabilities.

Storage Inspector

The Storage Inspector shows localStorage, sessionStorage, and cookies in organized sections.

Usage

1. Launch the app
2. Enter a URL in the text field
3. Select "Embedded WebView" from the picker
4. Tap "Launch" to open the WebView
5. Tap "Debug" in the navigation bar to access debugging tools

Debugging Features

Console Monitoring

• View all JavaScript console output in real-time
• Filter by log level using color coding
• Copy specific log messages for further analysis

DOM Inspection

• Explore the complete DOM structure
• Search for specific elements or content
• View element attributes and text content
• Export HTML structure via copy/paste

Web Storage Inspection

• Complete localStorage, sessionStorage, and cookie access
• Organized sectioned display by storage type
• Auto-loading when storage tab is accessed
• Expandable values for long content

Search Capabilities

• Global search across DOM tree
• Highlight matching elements
• Filter tree to show only relevant branches
• Case-insensitive text matching

Future Enhancements

See PROJECT_PLAN.md

License

This project is for educational and development purposes.