WebViewBridge Guide

This skill helps use the WebViewBridge Swift package for WebPage (macOS 26.0+) bidirectional communication.

Package Overview

WebViewBridge is a Swift framework for WebPage API with JavaScript injection and bidirectional communication.

• Repository: https://github.com/Sunalamye/WebViewBridge
• Platforms: macOS 26.0+ (WebPage API)
• License: MIT

Installation

// Package.swift
dependencies: [
    .package(url: "https://github.com/Sunalamye/WebViewBridge.git", from: "1.0.0"),
]

targets: [
    .target(
        name: "YourApp",
        dependencies: ["WebViewBridge"]
    ),
]

Architecture

WebViewBridge/
├── Core/
│   └── WebViewBridge.swift    - Main bridge class
├── JavaScript/
│   └── bridge-core.js         - Core JS utilities
└── WebViewBridgeKit.swift     - Version info

Quick Start

1. Create Bridge & Register Modules

import WebViewBridge
import WebKit

@available(macOS 26.0, *)
@MainActor
class MyViewController: NSViewController {
    let bridge = WebViewBridge(handlerName: "myBridge")
    var webPage: WebPage?

    override func viewDidLoad() {
        super.viewDidLoad()

        // Register core modules
        bridge.registerCoreModules()

        // Register custom module
        bridge.registerModule(JavaScriptModule(
            name: "my-module",
            source: """
                window.myApp = {
                    sendMessage: function(msg) {
                        window.__bridgeCore.sendToSwift('custom_message', { message: msg });
                    }
                };
            """
        ))

        // Handle messages
        bridge.onMessage = { type, data in
            print("Received: \(type) - \(data)")
        }

        // Configure WebPage
        var configuration = WebPage.Configuration()
        let userContentController = WKUserContentController()
        bridge.configure(contentController: userContentController)
        configuration.userContentController = userContentController

        // Create WebPage
        webPage = WebPage(configuration: configuration)
        bridge.configure(webPage: webPage!)
    }
}

2. JavaScript → Swift

// Using bridge-core
window.__bridgeCore.sendToSwift('my_event', { key: 'value' });

// Using custom API
window.myApp.sendMessage('Hello!');

3. Swift → JavaScript

Task {
    // ⚠️ MUST use `return` statement!
    let title = try await bridge.callJavaScript("return document.title")
}

⚠️ Critical: Return Statement

WebPage.callJavaScript() requires return statement!

// ❌ WRONG - returns null
try await bridge.callJavaScript("document.title")

// ✅ CORRECT
try await bridge.callJavaScript("return document.title")
try await bridge.callJavaScript("return JSON.stringify({a: 1})")

JavaScriptModule

let module = JavaScriptModule(
    name: "my-module",
    source: "window.myAPI = { ... };",
    injectAtStart: true,    // default: true
    mainFrameOnly: false    // default: false
)

// Load from bundle
let module = JavaScriptModule.fromBundle(named: "my-script", bundle: .main)

WebViewBridgeDelegate

@available(macOS 26.0, *)
public protocol WebViewBridgeDelegate: AnyObject {
    func bridge(_ bridge: WebViewBridge, didReceiveMessage type: String, data: [String: Any])
    func bridge(_ bridge: WebViewBridge, webSocketStatusChanged connected: Bool)  // optional
    func bridge(_ bridge: WebViewBridge, didEncounterError error: Error)  // optional
}

bridge-core.js API

// Send to Swift
window.__bridgeCore.sendToSwift(type, data)

// Log
window.__bridgeCore.log(message)

// Base64
window.__bridgeCore.arrayBufferToBase64(buffer)
window.__bridgeCore.base64ToArrayBuffer(base64)
window.__bridgeCore.blobToBase64(blob, callback)

// WebSocket interceptor
window.__bridgeCore.installWebSocketInterceptor({
    shouldIntercept: (url) => url.includes('api.example.com')
})

Message Types

Complete Example

@available(macOS 26.0, *)
@MainActor
class WebManager {
    let bridge = WebViewBridge(handlerName: "app")
    var webPage: WebPage?

    func setup() {
        bridge.registerCoreModules()
        bridge.registerModule(JavaScriptModule(
            name: "app-api",
            source: """
                window.App = {
                    notify: (msg) => __bridgeCore.sendToSwift('notify', {msg})
                };
            """
        ))

        bridge.onMessage = { type, data in
            if type == "notify", let msg = data["msg"] as? String {
                print("Notification: \(msg)")
            }
        }

        var config = WebPage.Configuration()
        let ucc = WKUserContentController()
        bridge.configure(contentController: ucc)
        config.userContentController = ucc

        webPage = WebPage(configuration: config)
        bridge.configure(webPage: webPage!)
    }

    func getTitle() async -> String? {
        try? await bridge.callJavaScript("return document.title") as? String
    }
}

Checklist

• Using @available(macOS 26.0, *)
• Called registerCoreModules()
• Configured both contentController and webPage
• Using return in callJavaScript()
• Set onMessage or delegate

Reference Documentation

• WebViewBridge Reference - Full API and examples