Selenium Java client: proper way of how to know that the certain element got disappeared

Im one my previous posts I suggested the way on how to ensure the certain element disappeated in your test scenario code. That usually the case of Web UI testing as it is not only important that something is shown on your click but also that something stopped being shown. Now let me introduce the right way on how to do that :)

So assume you have the following function devoted to looking up the fact the element on the page disappeared. You call it somewhere from your scenario code.

public boolean lookupXPathDoesNotExist(final String xpath) throws CustomAutomationException {
 
try{
 new WebDriverWait(getDriver(), AWAITING_THRESHOLD_MS/1000, 1000).until(
  new ExpectedCondition<Boolean>(){
   @Override
   public Boolean apply(WebDriver d) {
    if (d.findElements(By.xpath(xpath)).isEmpty()){
     return new Boolean(true);
    }else{
     return new Boolean(false);
    }
   }
  }
 );;
}catch(org.openqa.selenium.TimeoutException e){
 throw new CustomAutomationException("Timeout exceeded - however the element is still visible");
}
return true;
}

To make it work you should consider the following:
AWAITING_THRESHOLD_MS - is the constant holding the timeout you'preffer to fail your scenario after in case the element is still on the page
getDriver() - is the function that somehow returns the current acting webdriver
1000 (the last parameter of WebDriverWait method) - the interval between repeated tries

Read also How To Check That Element Is Present In Another Element