Waiting mechanism in Selenium
Waiting mechanism in Selenium and Java can be categorized as below:
- Demonstrate a program which don’t use waiting mechanism to understand the importance of waiting mechanism in Selenium
- NoSuchElementException
- Using Thread.sleep() in Java to overcome the waiting problems
- Implicit Wait – Instead of halting the program till the specified time is reached, Implicit wait will wait for all the web elements dynamically (i.e. Global wait)
- driver.manage().timeouts().implicitlyWait(Duration.ofSeconds(10));
- Explicit Wait – Instead of waiting for all the statements in the program, Explicit wait will wait only for the specific web element
- WebDriverWait wait = new WebDriverWait(driver,Duration.ofSeconds(30));
- WebElement element = wait.until(ExpectedConditions.visibilityOfElementLocated(By.linkText(“Facebook”)));
- element.click();
- Also demonstrate ‘ElementToBeClickable’
- Fluent Wait – Use Duration.ofSeconds(30) in the deprecated methods
- Copy the FluentWait code from Selenium API Documentation
- Import Function from google.common.base
- Import NoSuchElementException from selenium
Handling Ajax Calls in Selenium
- Web Pages make Ajax calls, to retrieve small amount of data from server without the need for reloading the page
- Example for Ajax call
- Selenium WebDriver handles Ajax calls using Waiting mechanism
- Implicit Wait
- Explicit Wait
- Fluent Wait
- etc.
- Practical demonstration
Solving Synchronization Problem in Selenium
- Selenium is faster and it won’t wait for any element on the web page by default
- If the element is not available, Selenium will simply throw NoSuchElementException
- To handle this problem, we have to use Waiting Mechanism in Selenium:
- Implicit Wait
- Explicit Wait
- Fluent Wait
- etc.
Waiting for an Element to be displayed on the page
- Sometimes, UI element won’t be displayed on the page immediately and make take time to display after performing an action
- As Selenium WebDriver cannot wait for the UI element, we have to explicitly wait until the UI element is displayed on the page.
- Practical Demonstration – omayo
Waiting for an Element to be click-able
- Sometimes, we have to wait for the UI element to be clickable, as it won’t be clickable by default
- Practical Demonstration – verifalia email checker
Waiting for an Alert to be present
- Sometimes, we have to wait for the alert before we perform any operations on the alert
- Practical Demonstration – omayo
- TimeoutException will be displayed if the alert is not displayed, despite of waiting
Loading Process Icon and How to Wait for the required UI element on the web page
- We get an Exception when we try to perform operation element, which is not displayed due to the loading icon
- In this case, if we wait for the required UI element, things may or may not work
- Instead, we have to wait for the loading icon to disappear by writing some programming logic
- We have to pause the debugger if required
- Practical Demonstration – Internet Heroku
pageLoadTimeout and TimeoutException – Selenium Exception Type
- By default Selenium WebDriver waits indefinitely, until the page to load without any time limit
- But we can set time limit for the web page to load using pageLoadTimeout()
- driver.manage().timeouts().pageLoadTimeout(Duration.ofSeconds(x))
- If the page doesn’t load in the specified time, we will get TimeoutException
- Practical Demonstration
- Omayo website page takes 4 seconds to load
- But if we set the limit to 2 seconds to load using pageLoadTimeout(), we get this TimeoutException
By,
Arun Motoori