Updating JavaScript alert title in Android webview: A guide for developers

Question

Updating JavaScript alert title in Android webview: A guide for developers

I have integrated a web view in my Android application, which contains a button. When the button is clicked, it triggers a JavaScript function that displays an alert box with the title "The page at 'file://' says". I would like to customize this title to display my own text. How can I achieve this?

javascript java android webview

Answer 1

Answer №1

After spending some time on it, I managed to tackle this issue by incorporating the setWebChromeClient method:

webView.setWebChromeClient(new WebChromeClient() {

    @Override
    public boolean onJsAlert(WebView view, String url, String message, final JsResult result) {
        AlertDialog dialog = new AlertDialog.Builder(view.getContext()).
                setTitle("YourAlertTitle").
                setMessage(message).
                setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        //do nothing
                    }
                }).create();
        dialog.show();

        return true;
    } });

Answer 2

After spending some time on it, I managed to tackle this issue by incorporating the setWebChromeClient method:

webView.setWebChromeClient(new WebChromeClient() {

    @Override
    public boolean onJsAlert(WebView view, String url, String message, final JsResult result) {
        AlertDialog dialog = new AlertDialog.Builder(view.getContext()).
                setTitle("YourAlertTitle").
                setMessage(message).
                setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        //do nothing
                    }
                }).create();
        dialog.show();

        return true;
    } });

Answer 3

Answer №2

MKY's answer is effective if your focus is solely on triggering the alert function. However, if you also need to address the functionalities of confirm and prompt, additional steps must be taken to override the onJsConfirm and onJsPrompt methods.

An important distinction between alert and confirm is that for confirm, it is necessary to incorporate a setNegativeButton that invokes the result.cancel() method within the lambda expression.

Dealing with prompt is more complex as it involves integrating a text editor into the dialog box. To achieve this, an EditText object needs to be created and included in the dialog using AlertDialog.Builder.setView, detailed in this specific response.

Furthermore, implementing a dismiss listener using setOnDismissListener across all three dialogs is advisable to account for scenarios where the dialog may be dismissed through means other than button clicks. This could occur if the user presses the back button or selects an area outside the dialog.

The following comprehensive code accommodates alert, confirm, and prompt situations. Remember to customize the placeholder "Title" in each respective method according to your desired title preference.

webView.setWebChromeClient(new WebChromeClient(){
    @Override
    public boolean onJsAlert(WebView view, String url, String message, JsResult result){
        new AlertDialog.Builder(view.getContext())
            .setTitle("Title")
            .setMessage(message)
            .setPositiveButton("OK", (DialogInterface dialog, int which) -> result.confirm())
            .setOnDismissListener((DialogInterface dialog) -> result.confirm())
            .create()
            .show();
        return true;
    }

    @Override
    public boolean onJsConfirm(WebView view, String url, String message, JsResult result){
        new AlertDialog.Builder(view.getContext())
            .setTitle("Title")
            .setMessage(message)
            .setPositiveButton("OK", (DialogInterface dialog, int which) -> result.confirm())
            .setNegativeButton("Cancel", (DialogInterface dialog, int which) -> result.cancel())
            .setOnDismissListener((DialogInterface dialog) -> result.cancel())
            .create()
            .show();
        return true;
    }

    @Override
    public boolean onJsPrompt(WebView view, String url, String message, String defaultValue, JsPromptResult result){
        final EditText input = new EditText(view.getContext());
        input.setInputType(InputType.TYPE_CLASS_TEXT);
        input.setText(defaultValue);
        new AlertDialog.Builder(view.getContext())
            .setTitle("Title")
            .setMessage(message)
            .setView(input)
            .setPositiveButton("OK", (DialogInterface dialog, int which) -> result.confirm(input.getText().toString()))
            .setNegativeButton("Cancel", (DialogInterface dialog, int which) -> result.cancel())
            .setOnDismissListener((DialogInterface dialog) -> result.cancel())
            .create()
            .show();
        return true;
    }
});

Answer 4

MKY's answer is effective if your focus is solely on triggering the alert function. However, if you also need to address the functionalities of confirm and prompt, additional steps must be taken to override the onJsConfirm and onJsPrompt methods.

An important distinction between alert and confirm is that for confirm, it is necessary to incorporate a setNegativeButton that invokes the result.cancel() method within the lambda expression.

Dealing with prompt is more complex as it involves integrating a text editor into the dialog box. To achieve this, an EditText object needs to be created and included in the dialog using AlertDialog.Builder.setView, detailed in this specific response.

Furthermore, implementing a dismiss listener using setOnDismissListener across all three dialogs is advisable to account for scenarios where the dialog may be dismissed through means other than button clicks. This could occur if the user presses the back button or selects an area outside the dialog.

The following comprehensive code accommodates alert, confirm, and prompt situations. Remember to customize the placeholder "Title" in each respective method according to your desired title preference.

webView.setWebChromeClient(new WebChromeClient(){
    @Override
    public boolean onJsAlert(WebView view, String url, String message, JsResult result){
        new AlertDialog.Builder(view.getContext())
            .setTitle("Title")
            .setMessage(message)
            .setPositiveButton("OK", (DialogInterface dialog, int which) -> result.confirm())
            .setOnDismissListener((DialogInterface dialog) -> result.confirm())
            .create()
            .show();
        return true;
    }

    @Override
    public boolean onJsConfirm(WebView view, String url, String message, JsResult result){
        new AlertDialog.Builder(view.getContext())
            .setTitle("Title")
            .setMessage(message)
            .setPositiveButton("OK", (DialogInterface dialog, int which) -> result.confirm())
            .setNegativeButton("Cancel", (DialogInterface dialog, int which) -> result.cancel())
            .setOnDismissListener((DialogInterface dialog) -> result.cancel())
            .create()
            .show();
        return true;
    }

    @Override
    public boolean onJsPrompt(WebView view, String url, String message, String defaultValue, JsPromptResult result){
        final EditText input = new EditText(view.getContext());
        input.setInputType(InputType.TYPE_CLASS_TEXT);
        input.setText(defaultValue);
        new AlertDialog.Builder(view.getContext())
            .setTitle("Title")
            .setMessage(message)
            .setView(input)
            .setPositiveButton("OK", (DialogInterface dialog, int which) -> result.confirm(input.getText().toString()))
            .setNegativeButton("Cancel", (DialogInterface dialog, int which) -> result.cancel())
            .setOnDismissListener((DialogInterface dialog) -> result.cancel())
            .create()
            .show();
        return true;
    }
});

Answer 5

Answer №3

Here is an example written in Kotlin:

It is crucial not to forget adding result.confirm(), as it will prevent your Webview from freezing!

override fun onJsAlert(
        view: WebView,
        url: String,
        message: String,
        result: JsResult
    ): Boolean {
        val title = "yourtitle"
        val dialog: AlertDialog =
            AlertDialog.Builder(view.context).setTitle(title).setMessage(message)
                .setPositiveButton("OK",
                    { dialog, which ->
                        result.confirm()
                    }).create()
        dialog.show()
        return true
}

On a side note, for individuals seeking a solution using both WebViewClient() and WebChromeClient(), it is possible to utilize them simultaneously. Not all override methods are available in one type of browser. Here is a way to implement this. Include

WebView.webChromeClient = ChromeClient()

and:

inner class ChromeClient internal constructor() : WebChromeClient() {
//Implement your methods here
}

Then proceed with launching the regular WebViewClient to perform tasks

WebView.webViewClient = object : WebViewClient() {
//Code implementation goes here
}

Answer 6

Here is an example written in Kotlin:

It is crucial not to forget adding result.confirm(), as it will prevent your Webview from freezing!

override fun onJsAlert(
        view: WebView,
        url: String,
        message: String,
        result: JsResult
    ): Boolean {
        val title = "yourtitle"
        val dialog: AlertDialog =
            AlertDialog.Builder(view.context).setTitle(title).setMessage(message)
                .setPositiveButton("OK",
                    { dialog, which ->
                        result.confirm()
                    }).create()
        dialog.show()
        return true
}

On a side note, for individuals seeking a solution using both WebViewClient() and WebChromeClient(), it is possible to utilize them simultaneously. Not all override methods are available in one type of browser. Here is a way to implement this. Include

WebView.webChromeClient = ChromeClient()

and:

inner class ChromeClient internal constructor() : WebChromeClient() {
//Implement your methods here
}

Then proceed with launching the regular WebViewClient to perform tasks

WebView.webViewClient = object : WebViewClient() {
//Code implementation goes here
}

Updating JavaScript alert title in Android webview: A guide for developers

Answer №1

Answer №2

Answer №3

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