How to use Interface HasVirtualAuthenticator class of org.openqa.selenium.virtualauthenticator package

It's not possible directly via the API, so you'll have to use a script injection.

The best way to determine if an element is visible in the viewport is to get the element at the supposed location with document.elementFromPoint. It returns null if it's not within the viewport and your element or a descendant if it is.

public static Boolean isVisibleInViewport(WebElement element) {
  WebDriver driver = ((RemoteWebElement)element).getWrappedDriver();

  return (Boolean)((JavascriptExecutor)driver).executeScript(
      "var elem = arguments[0],                 " +
      "  box = elem.getBoundingClientRect(),    " +
      "  cx = box.left + box.width / 2,         " +
      "  cy = box.top + box.height / 2,         " +
      "  e = document.elementFromPoint(cx, cy); " +
      "for (; e; e = e.parentElement) {         " +
      "  if (e === elem)                        " +
      "    return true;                         " +
      "}                                        " +
      "return false;                            "
      , element);
}

You don't have your XPath syntax right. You need quotes round the text attribute values you're matching against. Try:

d.findElement(By.xpath("//select[@id='category']/option[@id='cat2']")).click();

I found the answer and it worked for few Ajax and non-ajax sites I checked. After this patch I no longer need to do implicit waits even for ajax heavy pages, LeGac pointed out the following code in one of his comments to the question.

public static void checkPendingRequests(FirefoxDriver driver) {
    int timeoutInSeconds = 5;
    try {
        if (driver instanceof JavascriptExecutor) {
            JavascriptExecutor jsDriver = (JavascriptExecutor)driver;

            for (int i = 0; i< timeoutInSeconds; i++) 
            {
                Object numberOfAjaxConnections = jsDriver.executeScript("return window.openHTTPs");
                // return should be a number
                if (numberOfAjaxConnections instanceof Long) {
                    Long n = (Long)numberOfAjaxConnections;
                    System.out.println("Number of active calls: " + n);
                    if (n.longValue() == 0L)  break;
                } else{
                    // If it's not a number, the page might have been freshly loaded indicating the monkey
                    // patch is replaced or we haven't yet done the patch.
                    monkeyPatchXMLHttpRequest(driver);
                }
                Thread.sleep(1000);
            }
        }
        else {
           System.out.println("Web driver: " + driver + " cannot execute javascript");
        }
    }
    catch (InterruptedException e) {
        System.out.println(e);
    }    
}



public static void monkeyPatchXMLHttpRequest(FirefoxDriver driver) {
    try {
        if (driver instanceof JavascriptExecutor) {
            JavascriptExecutor jsDriver = (JavascriptExecutor)driver;
            Object numberOfAjaxConnections = jsDriver.executeScript("return window.openHTTPs");
            if (numberOfAjaxConnections instanceof Long) {
                return;
            }
            String script = "  (function() {" +
                "var oldOpen = XMLHttpRequest.prototype.open;" +
                "window.openHTTPs = 0;" +
                "XMLHttpRequest.prototype.open = function(method, url, async, user, pass) {" +
                "window.openHTTPs++;" +
                "this.addEventListener('readystatechange', function() {" +
                "if(this.readyState == 4) {" +
                "window.openHTTPs--;" +
                "}" +
                "}, false);" +
                "oldOpen.call(this, method, url, async, user, pass);" +
                "}" +
                "})();";
            jsDriver.executeScript(script);
        }
        else {
           System.out.println("Web driver: " + driver + " cannot execute javascript");
        }
    }
    catch (Exception e) {
        System.out.println(e);
    }
}

After every step you would need to call

checkPendingRequests(driver);

The executeScript() method from the JavascriptExecutor Interface can invoke multiple arguments in the form of arguments[0], arguments[1], etc

• As per your example, to javaScriptExecutor.executeScript("arguments[0].click()", webElement); to work you need to have the webElement defined. executeScript() method will take the reference of the element as arguments[0] along with the method to be performed [in this case click()] and the reference should be provided thereafter.

  WebElement webElement = driver.findElement(By.xpath("xpath_element"));
  JavascriptExecutor javaScriptExecutor = (JavascriptExecutor)driver;
  javaScriptExecutor.executeScript("arguments[0].click()", webElement);
  

• Similarly, an example of executeScript() with multiple arguments[] is as follows :

  JavascriptExecutor js = (JavascriptExecutor) driver; 
  js.executeScript("arguments[0].setAttribute('style', arguments[1])", driver.findElement(By.xpath("//input[@type='file']")), "0");
  

  Here in this example :

  • driver.findElement(By.xpath("//input[@type='file'] is referred as arguments[0]
  • "0" is referred as arguments[1]

You can find a relevant discussion in What is arguments[0] while invoking execute_script() method through WebDriver instance through Selenium and Python?

Like you said since the xpath for the next button is the same on every page it won't work. It's working as coded in that it does wait for the element to be displayed but since it's already displayed then the implicit wait doesn't apply because it doesn't need to wait at all. Why don't you use the fact that the url changes since from your code it appears to change when the next button is clicked. I do C# but I guess in Java it would be something like:

WebDriver driver = new FirefoxDriver();
String startURL = //a starting url;
String currentURL = null;
WebDriverWait wait = new WebDriverWait(driver, 10);

foo(driver,startURL);

/* go to next page */
if(driver.findElement(By.xpath("//*[@id='someID']")).isDisplayed()){
    String previousURL = driver.getCurrentUrl();
    driver.findElement(By.xpath("//*[@id='someID']")).click();  
    driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);

    ExpectedCondition e = new ExpectedCondition<Boolean>() {
          public Boolean apply(WebDriver d) {
            return (d.getCurrentUrl() != previousURL);
          }
        };

    wait.until(e);
    currentURL = driver.getCurrentUrl();
    System.out.println(currentURL);
} 

1. Launch 'regedit.exe' as 'Administrator'
2. Find the following registry key: 'HKEY_CLASSES_ROOT\CLSID{76A64158-CB41-11D1-8B02-00600806D9B6}'
3. Right click and select 'Permissions'
4. Press 'Advanced'
5. Double click on Administrators
6. Allow Full Control
7. Restart Remote Registry Service

UPDATE: As mentioned by @Kobi in comments,

If you cannot change the permissions, you need to first change the owner of this registry path, under "Advanced > Owner".

A step by step instructions on changing ownership can be found here.

C# convention is that interfaces are prefixed with an I, e.g. IEnumerable, IDisposable.

Java has no such convention.

I ran across this same problem and could not find any solutions. Came up with a solution and posting it here, hope this helps someone with the same problem. I created a class to handle stale elements depending on their type, cssselector, id, etc and simply call it like I would any other page object.

public void StaleElementHandleByID (String elementID)
{
    int count = 0;
    boolean clicked = false;
    while (count < 4 && !clicked)
    {
        try 
        {
            WebElement yourSlipperyElement= driver.findElement(By.id(elementID));
            yourSlipperyElement.click(); 
            clicked = true;
        } 
        catch (StaleElementReferenceException e)
        {
            e.toString();
            System.out.println("Trying to recover from a stale element :" + e.getMessage());
            count = count+1;
        }
    }
}

I'd recommend only using this on elements you know cause problems for WebDriver.

There is a page documenting Advanced User Interactions; which has a lot of great examples on how to generate a sequence of actions, you can find it here

// Configure the action
Actions builder = new Actions(driver);

builder.keyDown(Keys.CONTROL)
   .click(someElement)
   .click(someOtherElement)
   .keyUp(Keys.CONTROL);

// Then get the action:
Action selectMultiple = builder.build();

// And execute it:
selectMultiple.perform();   

or

Actions builder = new Actions(driver);

Action dragAndDrop = builder.clickAndHold(someElement)
   .moveToElement(otherElement)
   .release(otherElement)
   .build();

dragAndDrop.perform();