This article aims to deeply explore the technical details of the Huawei HarmonyOS Next system (up to API 12 as of now), and is summarized based on actual development practices.
It mainly serves as a vehicle for technical sharing and communication. Mistakes and omissions are inevitable. Colleagues are welcome to put forward valuable opinions and questions so that we can make progress together.
This article is original content, and any form of reprint must indicate the source and the original author.

Introduction

In the development environment of HarmonyOS Next, the ArkWeb framework provides developers with a powerful set of tools for building high-performance and secure Web applications. This article will deeply explore how to build a high-efficiency and secure Web component, helping readers master the advanced features of ArkWeb through abundant code examples and detailed steps.

Technical Preparation

Before starting, please ensure that you have installed the development tools of HarmonyOS Next and have a deep understanding of ArkTS (Ark TypeScript). In addition, being familiar with Web security and performance optimization principles will be helpful for better understanding the content of this article.

Chapter 1: Requirement Analysis and Design Principles

Requirement Analysis

Our goal is to create a component named AdvancedWebView that will have the following functions:

• Securely load and render remote web pages.
• Support preloading and lazy loading mechanisms.
• Provide flexible configuration options, including CORS policies and Content Security Policy (CSP).
• Achieve in-depth interaction with native applications. ### Design Principles
• Security: Ensure that all loaded content adheres to strict security standards.
• Performance: Optimize loading time and resource consumption.
• Maintainability: Have a clear code structure that is easy to maintain and extend. ## Chapter 2: Component Architecture and Implementation ### Component Architecture The architecture design of the AdvancedWebView component is as follows:
• WebView: The core Web view used to display web page content.
• SecurityManager: Responsible for implementing security policies.
• PerformanceOptimizer: Optimizes the performance of the Web view.
• InteractionHandler: Handles interactions with native applications. ### Implementation Steps #### 2.1 Creating the WebView Component

@Entry
@Component
struct AdvancedWebView {
  // Component states
  @State private src: string = '';
  @State private isLoading: boolean = true;
  @State private error: string | null = null;
  // Build method
  build() {
    Column() {
      if (this.isLoading) {
        // Loading state
        Progress().width('100%').height('5vp');
      } else if (this.error) {
        // Error state
        Text(this.error).fontSize(18).color('#FF0000');
      } else {
        // Normally display the WebView
        Web({ src: this.src })
         .width('100%')
         .height('100%')
         .onLoad(() => {
            this.isLoading = false;
          })
         .onError((err) => {
            this.error = err.message;
            this.isLoading = false;
          });
      }
    }
  }
  // Method to set the URL
  setSrc(newSrc: string) {
    this.src = newSrc;
    this.isLoading = true;
    this.error = null;
  }
}

2.1 Implementing the SecurityManager

class SecurityManager {
  // Enforce HTTPS
  static enforceHttps(url: string): string {
    return url.startsWith('https://')? url : `https://${url}`;
  }
  // Set CORS policy
  static setCorsPolicy(webview: Web, policy: CorsPolicy) {
    // Apply the CORS policy
    webview.setCorsPolicy(policy);
  }
  // Set CSP
  static setContentSecurityPolicy(webview: Web, policy: string) {
    // Apply the CSP
    webview.setContentSecurityPolicy(policy);
  }
}

2.3 Implementing the PerformanceOptimizer

class PerformanceOptimizer {
  // Preload resources
  static preloadResources(resources: string[]) {
    resources.forEach((resource) => {
        // Preloading logic
        const request = new XMLHttpRequest();
        request.open('GET', resource, true);
        request.send();
    });
  }
  // Enable lazy loading mechanism
  static enableLazyLoading(webview: Web) {
    // Enable lazy loading
    webview.setRenderMode(RenderMode.LAZY);
  }
}

2.4 Implementing the InteractionHandler

class InteractionHandler {
  // Send a message to the WebView
  static postMessage(webview: Web, message: any) {
    webview.postMessage(message);
  }
  // Listen for messages from the WebView
  static onMessage(webview: Web, callback: (message: any) => void) {
    webview.onMessage = callback;
  }
}

Chapter 3: Component Integration and Testing

Integration into the Application

Integrate the AdvancedWebView component into your HarmonyOS Next application, ensuring that all security and performance optimization measures have been implemented.

// Example: Using AdvancedWebView in an application
const advancedWebView = new AdvancedWebView();
advancedWebView.setSrc(SecurityManager.enforceHttps('https://www.example.com'));
SecurityManager.setCorsPolicy(advancedWebView, { /* CORS policy configuration */ });
SecurityManager.setContentSecurityPolicy(advancedWebView, "default-src 'self'; script-src 'self' 'unsafe-inline'; object-src 'none';");
PerformanceOptimizer.preloadResources(['https://www.example.com/styles.css', 'https://www.example.com/scripts.js']);
PerformanceOptimizer.enableLazyLoading(advancedWebView);
InteractionHandler.onMessage(advancedWebView, (message) => {
  // Handle the message received from the WebView
  console.log('Received message from WebView:', message);
});
// Add the WebView to the page
advancedWebView.appendTo(document.body);

Testing

Testing is a crucial step to ensure that the component works as expected. Here are some testing strategies:

Functional Testing

• Ensure that the WebView can load the specified URL.
• Verify that the CORS policy and CSP are correctly implemented.
• Check whether the preloading and lazy loading mechanisms are effective. #### Security Testing
• Use OWASP ZAP or a similar tool for security scanning to ensure there are no common security vulnerabilities.
• Verify that the enforcement of HTTPS is effective.
• Simulate cross-site scripting attacks (XSS) to ensure that the CSP can prevent the execution of malicious scripts. #### Performance Testing
• Use the browser's developer tools to analyze the page loading time.
• Monitor the memory and CPU usage to ensure that the component does not cause resource leaks.
• Use tools like Lighthouse for performance auditing. ## Chapter 4: Best Practices and Extensions ### Best Practices
• Code Separation: Separate the business logic from the WebView's configuration for easier maintenance and testing.
• Error Handling: Provide clear error messages and recovery strategies to enhance the user experience.
• Documentation and Comments: Write detailed documentation and code comments to help other developers understand and use the component. ### Extensions
• Plugin System: Allow developers to extend the functionality of AdvancedWebView through plugins.
• Custom Events: Implement a custom event system for more flexible handling of interactions.
• Theme Customization: Provide theme customization functionality to allow users to customize the appearance of the WebView according to brand requirements. ## Conclusion Through this article, we have deeply explored how to build a high-efficiency and secure Web component using the ArkWeb framework in HarmonyOS Next. We have introduced the design principles, architecture, implementation steps, integration methods, and testing strategies of the component. In addition, we have also discussed best practices and extension possibilities to help you further enhance the functionality and performance of the component. Hope this article can provide valuable guidance for your HarmonyOS Next application development and inspire your innovative thinking in building Web components. Awesome!