When Web meet Native App
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The document discusses the integration of webviews in Android applications, detailing their configuration, functionality, and key components such as WebViewClient and WebChromeClient. It provides technical insights on using webviews, including JavaScript interaction, handling URLs, and debugging methods. The conclusion emphasizes the importance of combining web and native applications to enhance user experience.
When Web meet Native App
- 1. CONFIDENTIAL & PROPRIETARY Page Title SUBTITLE 1 When Web meet Na6ve App Eric Chuang 當網⾴頁遇上原⽣生App
- 2. CONFIDENTIAL & PROPRIETARY When Web meet Na6ve App Yahoo Taiwan Mobile Team Eric Chuang 2
- 3. CONFIDENTIAL & PROPRIETARY About Me • Eric Chuang (ddsakura) • WebConf 2012 Speaker • Yahoo Lead Engineer 3 • Full Stack Engineer ? – Developed Yahoo E-‐Commerce Mobile Web – Developed Yahoo E-‐Commerce 超級商城 iPhone App – Developed Yahoo E-‐Commerce 拍賣 Android App
- 5. 猜猜哪裡是 Web？
- 6. Web in Auc6on Android App
- 7. CONFIDENTIAL & PROPRIETARY What is Webview • A View that displays web pages. • Android – Since API 1 • iOS – UIWebView – MKWebView 7
- 8. CONFIDENTIAL & PROPRIETARY 曾經我以為 Android Webview > iOS UIWebview (can not use Nitro JavaScript Engine ) 8 Android Webview == Android Browser
- 10. CONFIDENTIAL & PROPRIETARY hWp://beta.html5test.com/
- 11. CONFIDENTIAL & PROPRIETARY 結果… 11 Android Webview != Android Browser Android Webview v.s. iOS UIWebview/MKWebview
- 13. CONFIDENTIAL & PROPRIETARY Android Webview version • Android 4.4 – Chromium 30 13 • Android 4.4.3 – Chromium 33 • Android 5.0 – Chromium 37 • And in google play – hWps://play.google.com/store/apps/details?id=com.google.android.webview
- 15. CONFIDENTIAL & PROPRIETARY Android Webview version • Android before 4.4 – Old Webview – Vendor may “improve” their webview – ref: hWp://slides.com/html5test/the-‐android-‐browser#/12 15
- 16. CONFIDENTIAL & PROPRIETARY SO WE NO LONGER HAVE ONE WEBVIEW FOR EACH ANDROID VERSION BUT 16 ONE FOR SAMSUNG, AND ONE FOR HTC, AND ONE FOR ...
- 17. CONFIDENTIAL & PROPRIETARY Let’s start webview • We need permission 17 <uses-‐permission android:name="android.permission.INTERNET" /> • Basic usage WebView mWebview = new WebView(this); mWebview.loadUrl(“file:///android_asset/www/index.html”); mWebview.loadUrl(“hWp://tw.yahoo.com/“); String summary = “<html><body>Hello World</body></html>”; mWebview.loadData(summary, "text/html", null);
- 18. CONFIDENTIAL & PROPRIETARY Local Assets • file:///android_asset/ – The assets directory of an Android app is located at src/main/assets inside your Android Studio project. 18
- 19. CONFIDENTIAL & PROPRIETARY How about JavaScript • WebViews don't allow JavaScript by default. 19 // Enable JavascriptWebSepngs webSepngs = mWebView.getSepngs(); webSepngs.setJavaScriptEnabled(true);
- 20. CONFIDENTIAL & PROPRIETARY Configure webview • Websepngs – setJavaScriptEnabled • The default is false. – setGeoloca6onEnabled • The default is true. • ACCESS_COARSE_LOCATION, ACCESS_FINE_LOCATION – setBuiltInZoomControls • The default is false. – setDomStorageEnabled • The default value is false. 20hWp://developer.android.com/reference/android/webkit/WebSepngs.html
- 21. CONFIDENTIAL & PROPRIETARY Configure webview cont. • UserAgent – getUserAgentString – setUserAgentString 21 Mozilla/5.0 (Linux; U; Android 4.1.1; en-‐gb; Build/KLP) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Safari/534.30 Mozilla/5.0 (Linux; Android 4.4; Nexus 5 Build/_BuildID_) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/ 30.0.0.0 Mobile Safari/537.36 hWps://developer.chrome.com/mul6device/user-‐agent
- 23. CONFIDENTIAL & PROPRIETARY WebViewClient • Instance of WebViewClient that is the client callback. • It will be called when things happen that impact the rendering of the content, • Func6ons – onLoadResource – onPageStart – onPageFinish – onReceiveError – shouldInterceptRequest 23 hWp://developer.android.com/reference/android/webkit/WebViewClient.html
- 24. CONFIDENTIAL & PROPRIETARY WebChromeClient • Instance of WebChromeClient for handling all chrome func6ons. • This class is called when something that might impact a browser UI happens, for instance, progress updates and JavaScript alerts are sent here • Func6ons – onCloseWindow – onCreateWindow – onJsAlert – onJsPrompt – onJsConfirm 24 hWp://developer.android.com/reference/android/webkit/WebChromeClient.html
- 25. CONFIDENTIAL & PROPRIETARY Example between WebViewClient and WebChromeClient 25
- 26. CONFIDENTIAL & PROPRIETARY Handling Links • Default behavior: load that URL of the link in the default Android browser. 26 Intercept the url !!
- 27. CONFIDENTIAL & PROPRIETARY Intercep6ng WebView HTTP Requests • public boolean shouldOverrideUrlLoading (WebView view, String url) – Give the host applica6on a chance to take over the control when a new url is about to be loaded in the current WebView. 27
- 28. CONFIDENTIAL & PROPRIETARY Intercep6ng example 1 28 if (path.contains(ECWebView.WEB_URL_ECAUCTION_TYPE_PRODUCT_ITEM)) { showItemPage(url); // call na6ve component return true; } if (path.contains(ECWebView.WEB_URL_ECAUCTION_TYPE_SELLER_BOOTH)) { showSellerBooth(url); // call na6ve component return true; }
- 29. CONFIDENTIAL & PROPRIETARY Intercep6ng example 2 29 if (whiteList.indexOf(host) != -1) { toggleLoadingUI(true); return false; }
- 30. CONFIDENTIAL & PROPRIETARY From JavaScript to Java -‐ Android Part 30 public class WebAppInterface { Context mContext; /** Instan6ate the interface and set the context */ WebAppInterface(Context c) { mContext = c; } /** Show a toast from the web page */ @JavascriptInterface public void showToast(String toast) { Toast.makeText(mContext, toast, Toast.LENGTH_SHORT).show(); } } webView.addJavascriptInterface(new WebAppInterface(this), "Android");
- 31. CONFIDENTIAL & PROPRIETARY From JavaScript to Java -‐ HTML Part 31 <input type="buWon" value="Say hello" onClick="showAndroidToast('Hello Android!')" /> <script type="text/javascript"> func6on showAndroidToast(toast) { Android.showToast(toast); } </script>
- 32. CONFIDENTIAL & PROPRIETARY From Java to JavaScript 32 mWebView.loadUrl("javascript:window.cartList.closeOverlay()");
- 33. CONFIDENTIAL & PROPRIETARY Naviga6ng web page history 33 @Override public boolean onKeyDown(int keyCode, KeyEvent event) { // Check if the key event was the Back buWon and if there's history if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) { myWebView.goBack(); return true; } // If it wasn't the Back key or there's no web page history, bubble up to the default // system behavior (probably exit the ac6vity) return super.onKeyDown(keyCode, event); }
- 34. CONFIDENTIAL & PROPRIETARY Cache Web Resources 34 @Override public WebResourceResponse shouldInterceptRequest(WebView view, String url) { if(url.startsWith("hWp://mydomain.com/ar6cle/") { String cacheFileName = url.substring(url.lastIndexOf("/"), url.length()); this.urlCache.register(url, cacheFileName, "text/html", "UTF-‐8", 60 * UrlCache.ONE_MINUTE); } return this.urlCache.load(url); }
- 35. CONFIDENTIAL & PROPRIETARY Android Lollipop • Mixed content issue 35 if (android.os.Build.VERSION.SDK_INT >= 21) { webSepngs.setMixedContentMode(WebSe<ngs.MIXED_CONTENT_ALWAYS_ALLOW); }
- 36. CONFIDENTIAL & PROPRIETARY Cookie • CookieManager – Manages the cookies used by an applica6on's WebView instances. • setCookie(String url, String value) • getCookie(url) • CookieSyncManager – This class was deprecated in API level 21. The WebView now automa6cally syncs cookies as necessary. You no longer need to create or use the CookieSyncManager. To manually force a sync you can use the CookieManager method flush() which is a synchronous replacement for sync(). 36
- 37. CONFIDENTIAL & PROPRIETARY Handle HWp Error 37 @Override public void onReceivedError(WebView view, int errorCode, String descrip6on, String failingUrl) { … } @Override public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) { handler.proceed(); // Ignore SSL cer6ficate errors }
- 38. CONFIDENTIAL & PROPRIETARY Handle HWp Error bug • onReceivedError STILL does not receive HTTP Errors – hWps://code.google.com/p/android/issues/detail?id=82069 38 @Override public void onPageFinished(WebView view, String url) { if (WEBPAGE_ERROR_HTML_TITLE.indexOf(mWebContentTitle) != -1) { mListener.onPageReceivedError(view, WEBPAGE_ERROR_CODE, mWebContentTitle, url); } }
- 39. CONFIDENTIAL & PROPRIETARY Debugging webview • Requirements – Chrome 32 or later installed on your development machine. – A USB cable to connect your Android device. – For app debugging: Android 4.4+ and a WebView configured for debugging. 39 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) { WebView.setWebContentsDebuggingEnabled(true); }
- 40. CONFIDENTIAL & PROPRIETARY Debugging webview cont. • The chrome://inspect page displays a list of debug-‐ enabled WebViews on your device. • To start debugging, click inspect below the WebView you want to debug. • As of KitKat 4.4.3, screencast is available for both browser tabs and Android WebViews. 40
- 41. CONFIDENTIAL & PROPRIETARY Tes6ng with Webview • Robo6um – hWps://code.google.com/p/robo6um/ 41 // Type in text box WebElement txtSearch = solo.getWebElement(By.name("q"), 0); txtSearch.setTextContent("Hello"); // click buWon WebElement btnSearch = (WebElement) solo.getWebElement(By.name("btnG"), 0); solo.clickOnWebElement(btnSearch);
- 42. CONFIDENTIAL & PROPRIETARY Project that Improve Webview • Crosswalk – hWps://crosswalk-‐project.org/ – Develop around device fragmenta6on – Provide a feature rich experience all on Android 4.x devices – Easily debug with Chrome DevTools – Improve the performance of HTML, CSS, and JavaScript 42
- 43. CONFIDENTIAL & PROPRIETARY Conclusion • 這不是⾮非⿊黑即⽩白的世界 – Web 跟 Na6ve App 亦然 • 讓 Web 和 Na6ve App 共舞 – 提供使⽤用者最好的體驗 43
- 44. CONFIDENTIAL & PROPRIETARY Thank you 44 Eric Chuang hKp://bit.ly/1JkyR1W