WebDriver Fundamentals

Understanding WebDriver API

Selenium WebDriver provides a powerful API to control browsers programmatically. Let’s master the fundamentals.

WebDriver Interface

WebDriver is the core interface for browser automation:

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;

WebDriver driver = new ChromeDriver();

Navigation Methods

Control browser navigation:

// Navigate to URL
driver.get("https://example.com");

// Alternative navigation
driver.navigate().to("https://example.com");

// Browser history
driver.navigate().back();
driver.navigate().forward();
driver.navigate().refresh();

// Get current URL
String currentUrl = driver.getCurrentUrl();

// Get page title
String title = driver.getTitle();

// Get page source
String pageSource = driver.getPageSource();

Locator Strategies

WebDriver provides 8 locator strategies:

1. ID (Most Reliable)

import org.openqa.selenium.By;
import org.openqa.selenium.WebElement;

WebElement element = driver.findElement(By.id("username"));
element.sendKeys("testuser");

2. Name

WebElement email = driver.findElement(By.name("email"));
email.sendKeys("test@example.com");

3. Class Name

WebElement button = driver.findElement(By.className("btn-primary"));
button.click();

4. Tag Name

WebElement heading = driver.findElement(By.tagName("h1"));
String text = heading.getText();

5. Link Text

WebElement link = driver.findElement(By.linkText("Sign Up"));
link.click();

6. Partial Link Text

WebElement partialLink = driver.findElement(By.partialLinkText("Sign"));

7. CSS Selector (Powerful & Fast)

// By ID
WebElement elem1 = driver.findElement(By.cssSelector("#username"));

// By class
WebElement elem2 = driver.findElement(By.cssSelector(".btn-primary"));

// By attribute
WebElement elem3 = driver.findElement(By.cssSelector("input[type='email']"));

// By hierarchy
WebElement elem4 = driver.findElement(By.cssSelector("div.container > button"));

// Complex selectors
WebElement elem5 = driver.findElement(By.cssSelector("input[name='username'][type='text']"));

8. XPath (Most Flexible)

// Absolute XPath (avoid - brittle)
WebElement elem1 = driver.findElement(By.xpath("/html/body/div[1]/form/input[1]"));

// Relative XPath (preferred)
WebElement elem2 = driver.findElement(By.xpath("//input[@id='username']"));

// Text-based
WebElement elem3 = driver.findElement(By.xpath("//button[text()='Submit']"));

// Contains
WebElement elem4 = driver.findElement(By.xpath("//div[contains(@class, 'error')]"));

// Axes
WebElement elem5 = driver.findElement(By.xpath("//label[@for='email']/following-sibling::input"));

Element Interaction Methods

Input Elements

WebElement input = driver.findElement(By.id("search"));

// Type text
input.sendKeys("Selenium WebDriver");

// Clear text
input.clear();

// Get value
String value = input.getAttribute("value");

// Submit form
input.submit();

Buttons and Links

WebElement button = driver.findElement(By.id("submitBtn"));

// Click
button.click();

// Get text
String text = button.getText();

// Check if enabled
boolean isEnabled = button.isEnabled();

// Check if displayed
boolean isDisplayed = button.isDisplayed();

Checkboxes and Radio Buttons

WebElement checkbox = driver.findElement(By.id("agree"));

// Check if selected
if (!checkbox.isSelected()) {
    checkbox.click();
}

// Uncheck
if (checkbox.isSelected()) {
    checkbox.click();
}

Dropdowns

import org.openqa.selenium.support.ui.Select;

WebElement dropdown = driver.findElement(By.id("country"));
Select select = new Select(dropdown);

// Select by visible text
select.selectByVisibleText("United States");

// Select by value
select.selectByValue("us");

// Select by index
select.selectByIndex(1);

// Get selected option
WebElement selected = select.getFirstSelectedOption();
String text = selected.getText();

// Get all options
List<WebElement> options = select.getOptions();

Finding Multiple Elements

// Find all matching elements
List<WebElement> links = driver.findElements(By.tagName("a"));

for (WebElement link : links) {
    System.out.println(link.getAttribute("href"));
}

Wait Strategies

Implicit Wait

import java.time.Duration;

// Applied globally to all findElement calls
driver.manage().timeouts().implicitlyWait(Duration.ofSeconds(10));

Explicit Wait

import org.openqa.selenium.support.ui.WebDriverWait;
import org.openqa.selenium.support.ui.ExpectedConditions;

WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(10));

// Wait for element to be clickable
WebElement element = wait.until(
    ExpectedConditions.elementToBeClickable(By.id("submitBtn"))
);

// Wait for visibility
WebElement visible = wait.until(
    ExpectedConditions.visibilityOfElementLocated(By.className("success"))
);

// Wait for text to be present
wait.until(
    ExpectedConditions.textToBePresentInElementLocated(
        By.id("message"), "Success"
    )
);

Fluent Wait

import org.openqa.selenium.support.ui.FluentWait;
import org.openqa.selenium.NoSuchElementException;

FluentWait<WebDriver> fluentWait = new FluentWait<>(driver)
    .withTimeout(Duration.ofSeconds(30))
    .pollingEvery(Duration.ofSeconds(2))
    .ignoring(NoSuchElementException.class);

WebElement element = fluentWait.until(driver -> 
    driver.findElement(By.id("dynamicElement"))
);

Window and Frame Handling

Window Management

// Get current window handle
String mainWindow = driver.getWindowHandle();

// Get all window handles
Set<String> allWindows = driver.getWindowHandles();

// Switch to new window
for (String window : allWindows) {
    if (!window.equals(mainWindow)) {
        driver.switchTo().window(window);
        break;
    }
}

// Switch back
driver.switchTo().window(mainWindow);

// Window size
driver.manage().window().maximize();
driver.manage().window().setSize(new Dimension(1920, 1080));

Frame Handling

// Switch to frame by index
driver.switchTo().frame(0);

// Switch to frame by name or ID
driver.switchTo().frame("frameName");

// Switch to frame by WebElement
WebElement frameElement = driver.findElement(By.id("myFrame"));
driver.switchTo().frame(frameElement);

// Switch back to default content
driver.switchTo().defaultContent();

// Switch to parent frame
driver.switchTo().parentFrame();

Alert Handling

import org.openqa.selenium.Alert;

// Switch to alert
Alert alert = driver.switchTo().alert();

// Accept alert (OK)
alert.accept();

// Dismiss alert (Cancel)
alert.dismiss();

// Get alert text
String alertText = alert.getText();

// Type into alert (prompt)
alert.sendKeys("input text");
alert.accept();

JavaScript Execution

import org.openqa.selenium.JavascriptExecutor;

JavascriptExecutor js = (JavascriptExecutor) driver;

// Execute JavaScript
js.executeScript("alert('Hello from Selenium');");

// Scroll to element
WebElement element = driver.findElement(By.id("footer"));
js.executeScript("arguments[0].scrollIntoView(true);", element);

// Click hidden element
js.executeScript("arguments[0].click();", element);

// Get return value
Long height = (Long) js.executeScript("return document.body.scrollHeight;");

Screenshot Capture

import org.openqa.selenium.TakesScreenshot;
import org.openqa.selenium.OutputType;
import org.apache.commons.io.FileUtils;

// Take screenshot
TakesScreenshot ts = (TakesScreenshot) driver;
File source = ts.getScreenshotAs(OutputType.FILE);
File destination = new File("screenshots/test.png");
FileUtils.copyFile(source, destination);

Best Practices

1. Prefer CSS Selectors over XPath for better performance
2. Use Explicit Waits instead of Thread.sleep()
3. Unique Locators - ID is best, followed by CSS
4. Avoid Absolute XPath - use relative XPath
5. Handle Exceptions properly with try-catch
6. Close Resources - always call driver.quit()

Common Pitfalls

// ❌ Bad - Hard-coded sleep
Thread.sleep(5000);

// ✅ Good - Explicit wait
WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(10));
wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("element")));

// ❌ Bad - Absolute XPath
driver.findElement(By.xpath("/html/body/div[1]/div[2]/form/input[1]"));

// ✅ Good - Relative XPath
driver.findElement(By.xpath("//input[@id='username']"));

Next Steps

In the next lesson, we’ll implement the Page Object Model pattern to organize our code better.

Key Takeaways

✅ Master 8 locator strategies for element identification
✅ Use explicit waits for dynamic content
✅ Handle windows, frames, and alerts effectively
✅ Execute JavaScript when native methods fail