What is the most efficient way to wait for a page element (xpath) to show up in Selenium Webdriver?

Question

I am using Java and Selenium Webdriver in order to test the functionalities of a single page web application.

For this reason, clearly, elements are injected and removed from the DOM dynamically.

I know I can wait for an element to be present in the DOM using similar code that is using WebDriverWait (very neat template I wrote slightly changing GitHub):

public void waitForElement() throws Exception {
    /*
    Inject the following snippet in any web page to test the method
    <button class="i-am-your-class" onclick="alert('Wow, you pressed the button!');">Press me</button>
     */
    System.setProperty("webdriver.gecko.driver", "C:\\Program Files (x86)\\Mozilla Firefox\\geckodriver.exe");
    WebDriver driver = getDriver();
    WebDriverWait wait = new WebDriverWait(driver, 10); // 10 can be reduced as per Test Specifications
    driver.get("http://www.google.com");
    WebElement response = wait.until(ExpectedConditions.visibilityOfElementLocated(By.xpath("//*[@class='i-am-your-class']")));
    response.click();
    System.out.println("*****************************************************************************");
    System.out.println(response);
    System.out.println(response.getText());

    driver.close();
}

What I would like to know is if this is also the more efficient way to obtain such result using an xpath.

I have been researching on Stackoverflow and several answers point in a similar direction but no answer is focused on efficiency / performances:

• WebDriver - wait for element using Java
• Selenium WebDriver: wait for element to be present when locating with WebDriver.findElement is impossible

Thanks for your time and help.

Answer 1

There are a couple of facts which you need to consider as follows :

• WebDriverWait() for 100 shouldn't be a real-time waiter. Consider reducing it as per the Test Specifications. As an example, set it as 10 seconds :

  WebDriverWait wait = new WebDriverWait(driver, 10);
  

• Moving forward as you are invoking click() method so instead of ExpectedConditions as visibilityOfElementLocated() method use elementToBeClickable() method as follows :

  WebElement response = wait.until(ExpectedConditions.elementToBeClickable(By.xpath("//*[@class='i-am-your-class']")));
  

• Optimize your xpath including the tagName as in By.xpath("//tagName[@class='i-am-your-class']"). As an example :

  By.xpath("//a[@class='i-am-your-class']")
  

• Optimize your code to invoke click() as soon as the element is returned through WebDriverWait as follows :

  new WebDriverWait(driver, 20).until(ExpectedConditions.elementToBeClickable(By.xpath("//a[@class='i-am-your-class']"))).click();
  

Answer 2

I do not know for what reason you have said XPATH is preferred. I would like to add something about locators.

The XPATH you have written in your code can be easily replaced by a css selector. Here is the example.

div[class='i-am-your-class']  

Now the main question is why do you want to switch to different locators ?

• more efficiency.
• more fast as compared to xpath.
• more reliable.
• more performance.

You should always use locators in this order as suggested by Selenium contributors

1. ID
2. name
3. className
4. linkText
5. partialLinkText
6. tagName
7. cssSelector
8. XPath.

Note : Most of the time a cssSelector can replace Xpath, However Xpath has its own advantages which cssSelector do not provide.

For more reference you can go through this SO Link : Xpath vs Css selector