从 URL 同步加载 html（使用 Swift）的方式就像用户看到的那样

Question

我正在寻找最直接的方法来从页面获取完整的 html。页面加载后，JS 完成工作后。

速度并不重要。优化并不重要。主线程的锁定并不重要。

只有结果才是重要的：获取页面的完整 HTML 代码。同步进行。

---

我尝试使用 WKWebView 获取 html：

class InternetLoader {
    private let webView = WKWebView(frame: .zero)
    
    private let script = """
    window.onload = function() {
        document.body.innerHTML;
    };
    """
    
    private var resultHtml: String? = nil
    
    func getHTML(from url: URL) -> String {
        webView.load(URLRequest(url: url))
        
        let semaphore = DispatchSemaphore(value: 0)
        
        webView.evaluateJavaScript(script) { (result, error) in
            if let error = error {
                print("Error executing JavaScript: \(error.localizedDescription)")
            } else if let htmlContent = result as? String {
                self.resultHtml = htmlContent
            }
            
            semaphore.signal()
        }
        
        semaphore.wait()
        
        return resultHtml!
    }
}

用途：

let il = InternetLoader()
let html = il.getHTML(from: URL(string: "https://stackoverflow.com/questions"))

但它无休止地卡住了。

我做错了什么？

Answer 1

感谢命令行中的wkwebview。修改此以获得html

@MainActor
class InternetLoader: NSObject {
    
    lazy var webView: WKWebView = {
        let webView: WKWebView = WKWebView()
        webView.navigationDelegate = self
        return webView
    }()
    
    private var resultHtml: String? = nil
        
    var continuation: UnsafeContinuation<String?, Error>?
    
    func getHTML(from url: URL) async throws -> String? {
        return try await withUnsafeThrowingContinuation { continuation in
            self.continuation = continuation
            webView.load(URLRequest(url: url))
        }
    }
    
}

extension InternetLoader: WKNavigationDelegate {

    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
        webView.evaluateJavaScript("document.body.innerHTML") { [weak self] (result, error) in
            if let error = error {
                print("Error executing JavaScript: \(error.localizedDescription)")
            } else if let htmlContent = result as? String {
                self?.resultHtml = htmlContent
            }
            self?.continuation?.resume(returning: self?.resultHtml)
        }
    }
    
    func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
        continuation?.resume(throwing: error)
    }

    func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
        continuation?.resume(throwing: error)
    }
}


let loader = InternetLoader()
var html = ""
if let confirmedHtml = try? await loader.getHTML(from: URL(string: "https://stackoverflow.com/questions")!) {
    html = confirmedHtml
}
print(html)