How to use

findElementByCssSelector

method

in

org.openqa.selenium.firefox.FirefoxDriver

 FirefoxDriver driver = new FirefoxDriver();
driver.get("https://www.youtube.com/watch?v=JcbBNpYkuW4");

WebElement element = driver.findElementByCssSelector("#watch-discussion");
System.out.println(element.getText()); // this prints: loading..

// scrolll down so that comments start to load
driver.executeScript("window.scrollBy(0,500)", "");

Thread.sleep(20000);

List<WebElement> iframes = driver.findElements(By.xpath("//iframe"));

for(WebElement e : iframes) {       
  if(e.getAttribute("id") != null && e.getAttribute("id").startsWith("I0_")) {
  // switch to iframe which contains comments
  driver.switchTo().frame(e);
  break;
  }
}

// fetch all comments
List<WebElement> comments = driver.findElements(By.xpath("//div[@class='Ct']"));
for(WebElement e : comments) {      
  System.out.println(e.getText());
}

@Test
public void addBookToEmptyList() {
  String baseUrl = "http://localhost:" + port;
  browser.get(baseUrl);
  assertEquals("You have no books in your book list",
         browser.findElementByTagName("div").getText());
  browser.findElementByName("title").sendKeys("BOOK TITLE");
  browser.findElementByName("author").sendKeys("BOOK AUTHOR");
  browser.findElementByName("isbn").sendKeys("1234567890");
  browser.findElementByName("description").sendKeys("DESCRIPTION");
  browser.findElementByTagName("form").submit();
  WebElement dl = browser.findElementByCssSelector("dt.bookHeadline");
  assertEquals("BOOK TITLE by BOOK AUTHOR (ISBN: 1234567890)", dl.getText());
  WebElement dt = browser.findElementByCssSelector("dd.bookDescription");
  assertEquals("DESCRIPTION", dt.getText());
}