The error message "E/Web Console(8272): Uncaught ReferenceError: functionName is not defined:1" popped up when trying to load web views within a

Question

The error message "E/Web Console(8272): Uncaught ReferenceError: functionName is not defined:1" popped up when trying to load web views within a

I'm working on incorporating webviews into a view pager.

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View v = null;      
    v = inflater.inflate(R.layout.webview_layout, container, false);
    myWebView = (WebView)v.findViewById(R.id.webview1);
    WebSettings webSettings = myWebView.getSettings();      
    webSettings.setJavaScriptEnabled(true);
    webSettings.setAppCacheEnabled(true);
    webSettings.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
    myWebView.loadUrl("file:///android_asset/web/index.html");
    myWebView.setWebViewClient(new WebViewClient() {
        @Override
        public void onPageFinished(WebView view, String url) {
            myWebView.loadUrl("javascript:testFunction()");
        }
    }
}

After the page loads, a javascript function is triggered in onPageFinished(). While scrolling at a regular pace, the web pages load and the Javascript runs smoothly.

However, when scrolling rapidly, the following exception occurs:

> 09-06 14:29:06.750: E/Web Console(8272): Uncaught ReferenceError:
> testFunction is not defined:1

The testFunction() looks like this:

function testFunction(){
    console.log("TestFuntion");     
}

I would appreciate any assistance...

javascript android jquery webview android-viewpager

Answer 1

Answer №1

I found a solution to this issue

Simply set the webChromeClient and handle the error by reloading the page...

    myWebView.setWebViewClient(new WebViewClient() {
        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            isLoading = true;
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            myWebView.loadUrl("javascript:testFunction()");
        }
    });

    myWebView.setWebChromeClient(new WebChromeClient() {
        @Override
        public boolean onConsoleMessage(ConsoleMessage consoleMessage) {
            MessageLevel level = consoleMessage.messageLevel();
            if(level.ordinal() == 3) { // Error ordinal
                if(loading) {
                    myWebView.stopLoading();
                    myWebView.loadUrl(AppConstants.ARTICLE_PAGE_URL);
                }
            }
        }
        return false;
    }

Answer 2

I found a solution to this issue

Simply set the webChromeClient and handle the error by reloading the page...

    myWebView.setWebViewClient(new WebViewClient() {
        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            isLoading = true;
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            myWebView.loadUrl("javascript:testFunction()");
        }
    });

    myWebView.setWebChromeClient(new WebChromeClient() {
        @Override
        public boolean onConsoleMessage(ConsoleMessage consoleMessage) {
            MessageLevel level = consoleMessage.messageLevel();
            if(level.ordinal() == 3) { // Error ordinal
                if(loading) {
                    myWebView.stopLoading();
                    myWebView.loadUrl(AppConstants.ARTICLE_PAGE_URL);
                }
            }
        }
        return false;
    }

Answer 3

Answer №2

Here's a sample code snippet that you can modify to suit your needs:

Webview Code:

web.getSettings().setJavaScriptEnabled(true);
JavaScriptInterface JSInterface = new JavaScriptInterface(this);
web.addJavascriptInterface(JSInterface, "JSInterface");
setContentView(web);
web.loadUrl("file:///android_asset/demo.html");

Javascript Interface:

public class JavaScriptInterface {
    Context mContext;

    /** Instantiate the interface and set the context */
    JavaScriptInterface(Context c) {
        mContext = c;
    }

    public void showToast() {
        Toast.makeText(mContext, "Button Clicked", Toast.LENGTH_SHORT).show();
    }
}

Webpage Code:

<!DOCTYPE html>
<html>
  <head>
   <script>
     var i=0;
     function myFunction()
     {
       JSInterface.showToast();
     }
   </script>
 </head>

 <body>
    <button onclick="myFunction()">Try it</button>
    <p>By clicking the button above, a function will be called. The function will alert a message.</p>
 </body>
</html>

EDIT

function myFunction()
{
   // Add your custom code here
}

Answer 4

Here's a sample code snippet that you can modify to suit your needs:

Webview Code:

web.getSettings().setJavaScriptEnabled(true);
JavaScriptInterface JSInterface = new JavaScriptInterface(this);
web.addJavascriptInterface(JSInterface, "JSInterface");
setContentView(web);
web.loadUrl("file:///android_asset/demo.html");

Javascript Interface:

public class JavaScriptInterface {
    Context mContext;

    /** Instantiate the interface and set the context */
    JavaScriptInterface(Context c) {
        mContext = c;
    }

    public void showToast() {
        Toast.makeText(mContext, "Button Clicked", Toast.LENGTH_SHORT).show();
    }
}

Webpage Code:

<!DOCTYPE html>
<html>
  <head>
   <script>
     var i=0;
     function myFunction()
     {
       JSInterface.showToast();
     }
   </script>
 </head>

 <body>
    <button onclick="myFunction()">Try it</button>
    <p>By clicking the button above, a function will be called. The function will alert a message.</p>
 </body>
</html>

EDIT

function myFunction()
{
   // Add your custom code here
}

Answer 5

Answer №3

When I encountered the issue of getting an error message saying "Uncaught Reference Error: JavascriptInterfaceName is not defined" every second time I started my hybrid application on versions 4.3 and below, I found a solution with help from @Abi by implementing the following code in my WebChromeClient class:

@Override
@SuppressLint({"AddJavascriptInterface", "InflateParams"})
public boolean onConsoleMessage(@NonNull ConsoleMessage consoleMessage) {
    if("Uncaught ReferenceError: JavascriptInterfaceName is not defined".equals(consoleMessage.message())) {
        webView.addJavascriptInterface(new WebAppInterface(), "JavascriptInterfaceName ");
        webView.reload();
    }
    return super.onConsoleMessage(consoleMessage);
}

After making this change, the issue was resolved! Many thanks for your assistance!

Answer 6

When I encountered the issue of getting an error message saying "Uncaught Reference Error: JavascriptInterfaceName is not defined" every second time I started my hybrid application on versions 4.3 and below, I found a solution with help from @Abi by implementing the following code in my WebChromeClient class:

@Override
@SuppressLint({"AddJavascriptInterface", "InflateParams"})
public boolean onConsoleMessage(@NonNull ConsoleMessage consoleMessage) {
    if("Uncaught ReferenceError: JavascriptInterfaceName is not defined".equals(consoleMessage.message())) {
        webView.addJavascriptInterface(new WebAppInterface(), "JavascriptInterfaceName ");
        webView.reload();
    }
    return super.onConsoleMessage(consoleMessage);
}

After making this change, the issue was resolved! Many thanks for your assistance!

The error message "E/Web Console(8272): Uncaught ReferenceError: functionName is not defined:1" popped up when trying to load web views within a

Answer №1

Answer №2

Answer №3

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