The Selenium WebDriver provides an explicit wait for synchronizing tests, which provides a better way to wait over an implicit wait. Unlike an implicit wait, you can write and use pre-defined conditions or custom conditions for wait before proceeding further in the code.
The Selenium WebDriver provides the WebDriverWait and ExpectedConditions classes to implement an explicit wait.
The ExpectedConditions class provides a set of predefined conditions to wait for before proceeding further in the code. The following table shows some common conditions that we frequently come across when automating web browsers supported by the ExpectedConditions class:
|
Predefined condition |
Selenium method |
|---|---|
|
An element is visible and enabled |
|
|
An element is selected |
|
|
Presence of an element |
|
|
Specific text present in an element |
|
|
Element value |
|
|
Title |
|
Note
For more conditions, visit http://seleniumhq.github.io/selenium/docs/api/java/index.html.
In this recipe, we will explore some of these conditions with the WebDriverWait class.
Let's implement a test that uses the ExpectedConditions.titleContains() method to implement an explicit wait, as follows:
@Test
public void testExplicitWaitTitleContains()
{
//Go to the Google Home Page
WebDriver driver = new FirefoxDriver();
driver.get("http://www.google.com");
//Enter a term to search and submit
WebElement query = driver.findElement(By.name("q"));
query.sendKeys("selenium");
query.click();
//Create Wait using WebDriverWait.
//This will wait for 10 seconds for timeout before title is updated with search term
//If title is updated in specified time limit test will move to the text step
//instead of waiting for 10 seconds
WebDriverWait wait = new WebDriverWait(driver, 10);
wait.until(ExpectedConditions.titleContains("selenium"));
//Verify Title
assertTrue(driver.getTitle().toLowerCase().startsWith("selenium"));
driver.quit();
}We can define an explicit wait for a set of common conditions using the ExpectedConditions class. First, we need to create an instance of the WebDriverWait class by passing the driver instance and timeout for a wait, as follows:
WebDriverWait wait = new WebDriverWait(driver, 10);
Next, the ExpectedCondition is passed to the wait.until() method, as follows:
wait.until(ExpectedConditions.titleContains("selenium"));The WebDriverWait object will call the ExpectedConditions class object every 500 milliseconds until it returns successfully.