What is Synchronization: ensures that the test script interacts with web elements only when they are fully loaded and ready. This helps avoid errors that occur when elements are not yet available or intractable.
Synchronization is needed in Selenium
Synchronization is important because web elements might not be ready when test script tries to interact with them. Web applications can have varying load times due to factors like network issues, server delays, or dynamic content changes (such as AJAX), which can cause test failures if not handled properly.
Problem without synchronization:
StaleElementReferenceException: This error occurs if the web page updates or refreshes, causing Selenium to lose track of the element.
Timeout Exception: This error happens when the test script attempts to interact with an element that is not yet loaded or visible.
Synchronization solves these problems:
- Ensuring the web element is fully loaded and ready before interacting.
- Handling dynamic content (like AJAX updates) more reliably.
- Reducing test failures caused by timing issues.
✓Synchronization is achieved by using waits (like Implicit, Explicit, or Fluent Waits)
What is the use of wait: The use of wait in Selenium is to pause the test until the webpage or element is ready, so the test script doesn’t try to interact with things before they fully load. This helps prevent errors when pages are slow to respond.
1.Static wait(Thread.Sleep): Even though the locator is found, it will wait for maximum time
Thread.sleep(milliseconds);--->throws InterruptedException
Example:
Thread.sleep(5000);--->wait for 5 second
2.Dynamic wait: If the locator is found within some seconds,it will not wait till the maximum time. The main types of dynamic waits are:
Explicit Wait: you can wait for a certain condition, such as an element becoming clickable, visible, or present on the DOM, before taking action.
When to Use Explicit Wait:
✓When some elements take longer to load than others.
✓When you want to wait for specific conditions like visibility, clickability, or presence of an element.
Example:
WebDriver driver = new ChromeDriver();
driver.get("https://facebook.com");
// Create an explicit wait object with a maximum wait time of 15 seconds
WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(15));
// Wait until a specific element is clickable before interacting with it
WebElement buttonElement = wait.until(ExpectedConditions.elementToBeClickable(By.id("element")));
buttonElement.click();
Implicit Wait: implicit wait commands selenium to wait for a certain amount of time before throwing a "No such element" exception
When to Use It:
✓When all elements on your page might take time to load.
✓If you don’t need special conditions for different elements.
Example:
WebDriver driver = new ChromeDriver();
driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
// Wait for 10 seconds
driver.get("https://facebook.com");
WebElement element = driver.findElement(By.id("buttonElement"));
// This will wait up to 10 seconds if needed
Fluent Wait:
✓Set a maximum wait time.
✓Specify how often to check for the condition (polling frequency).
✓Ignore certain exceptions like NoSuchElementException while waiting for the condition.
When to Use Fluent Wait:
✓When elements may not load consistently and you want to periodically check for their availability.
✓When you need to ignore specific exceptions while waiting for an element.
difference between implict wait, explict wait and Fluent wait:
Implict wait:
• It is applicable for all the locators in the webpage.
• driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
• No options to ignore exceptions
Explict wait:
• We can set ExplicitWait for particular locator/condition.
• WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(10)); WebElement element = wait.until(ExpectedConditions.elementToBeClickable
• Handles specific conditions; no option to ignore exceptions
Fluent wait:
• Polls at defined intervals until the condition is met or timeout occurs
• Wait<WebDriver> wait = new FluentWait<>(driver).withTimeout(Duration.ofSeconds(10)).pollingEvery(Duration.ofSeconds(1)).ignoring(NoSuchElementException.class)
WebElement element = wait.until(driver -> driver.findElement(By.id("elementId")));
• Can ignore specific exceptions (e.g., NoSuchElementException)
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