StaleElementReferenceExceptions (console in eclipse) in Selenium Webdriver API

During running the automation script we got exception is occur when Firefox driver is trying to perform action on the element which is no longer exists or not valid due to page load or whatever reason.

WebElement element = driver.findElement(By.id("samplescript"));
// Before click on  something happened, DOM has changed due to page refresh, or element is removed //and re-added
element.click();

Now at the below example, the element which you are clicking is no longer valid due to some reason.

So it throws up the exception and its hands and gives control to automation tester, who get to know (the test/app author) should know exactly what may or may not happen.

In order to overcome this situation, Need to explicitly wait until the DOM is in a state where we are about to sure that DOM will not change.

ie, using a WebDriverWait syntex to wait for a specific element to exist:

https://www.youtube.com/watch?v=TmHILJhJfFo
https://www.youtube.com/watch?v=odxU3L1OB-M
 
// times out after 10 seconds

WebDriverWait wait = new WebDriverWait(driver, 200);

// While the following loop runing, the DOM has changes -

// page to be refresh state or element is removed and re-added

wait.until(elementIdentified(By.id("element")));       

// now it look like good - let's click the element

driver.findElement(By.id("sample")).click();

private static Function<WebDriver,WebElement> elementIdentified(final By locator) {

    return new Function<WebDriver, WebElement>() {

        @Override

        public WebElement apply(WebDriver driver) {

            return driver.findElement(locator);

        }

    };

}

We can also use here implicit waits, in which Webdriver API will check for the element to become present until the specified timeout:

driver.manage().timeouts().implicitlyWait(50, TimeUnit.SECONDS)