Post#42.Waits in Selenium

Waits in Selenium

What is wait? Why we need it?

It is the process of matching the speed of action and reaction, selenium does the action and web application shows the reaction.

Example: Click Login button gmail login (selenium does this action) web application navigates to the inbox (reaction)

Click on Compose button in Gmail

public class Gmail

{

              public static void main(String[] args)

              {

                             //open firefox browser

                             WebDriver driver=new FirefoxDriver();

                             //goto gmail.com

                             driver.get("https://www.gmail.com");

                             //enter text in username

              driver.findElement(By.xpath("//*[@id='email']")).sendKeys("username");

                             //enter text in password

              driver.findElement(By.xpath("//*[@id='Passwd']")).sendKeys("password");

                             //click on the signin button

                             driver.findElement(By.xpath("//*[@id='signIn']")).click();

                             //click on the compose button

                             driver.findElement(By.cssSelector("div[class='T-I J-J5-Ji T-I-KE L3']")).click();

              }

}

If you run the above program you might face "NoSuchElementException" Exception because selenium starts searching for the compose button immediately after clicking on the SignIn button it waits for few milli-seconds but normally gmail takes 3 to 4 second to open so selenium will not able to find it.

In most of the cases the selenium does the action in micro or milli-seconds but the application takes time in seconds.

At the same time selenium will not wait till it loads or becomes visible at the time selenium will not able to find the element within the java processing time so selenium throws “NoSuchElementException᾿.

We cannot alter the speed of the application, so we must slow down selenium.

Type of Waits in selenium WebDriver

There are several ways to synchronize the selenium with application

• Sleep
• pageLoadTimeout
• setScriptTimeout
• ImplicitlyWait
• ExplicitWait or WebDriverWait
• FluentWait

Sleep() in WebDriver

Sleep() is a method present in thread class, most of the java people might be familiar with this. It makes selenium to sleep for the specified time, we can specify the time

If you mention Thread.sleep(20); then selenium waits for 20 milli-seconds sleep method takes argument in milli-seconds as the input. If you want make the selenium to sleep for the 20 seconds means we need to mention like this Thread.sleep(20000);

Sleep() method will not worry about whether the element is present or not, it just sleeps till mentioned time. This is also called as static wait or blind wait, dead wait.

Syntax : Thread.sleep(Long milli-seconds);

Complete program for Sleep()

public class GmailLogin

{

              public static void main(String[] args) throws InterruptedException                                                                                       {

                             //open the firefox

                             WebDriver driver=new FirefoxDriver();

                             //sleep for 5 seconds

                             Thread.sleep(5000);

                             //open gmail.com

                             driver.get("https://www.gmail.com");

                             //sleep for 5 seconds

                             Thread.sleep(5000);

                             //enter the user name in the Email field

                            driver.findElement(By.id("Email")).sendKeys("username");

                             //sleep for 5 seconds

                             Thread.sleep(5000);

                             //enter the password in the password field

                            driver.findElement(By.id("Passwd")).sendKeys("password");

                             //sleep for 5 seconds

                             Thread.sleep(5000);

                             //sends the enter to the password field

                             //sendKeys always append the text present in the element

                             //it never erases the text in the element

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

              }

}

Consider the above program in which we are using sleep() method every time it waits for 5 seconds.

Let us consider practical application in that we are having more the 8 pages and 50 operations if we use Thread.sleep(10000) for 50 times then it is 500 seconds around 10 minutes, so the dead time is more but no one prefer to wait .