PageFactory initialization in Selenium Java - Test Execution Trace

Test Overview

This test opens a web page and verifies that a button is present using Selenium's PageFactory to initialize web elements.

Test Code - JUnit 5 with Selenium

Selenium Java

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.support.FindBy;
import org.openqa.selenium.support.PageFactory;
import org.openqa.selenium.chrome.ChromeDriver;
import org.junit.jupiter.api.*;

public class PageFactoryTest {
    WebDriver driver;

    @FindBy(id = "submit-btn")
    WebElement submitButton;

    @BeforeEach
    public void setUp() {
        driver = new ChromeDriver();
        driver.get("https://example.com");
        PageFactory.initElements(driver, this);
    }

    @Test
    public void testSubmitButtonIsDisplayed() {
        Assertions.assertTrue(submitButton.isDisplayed(), "Submit button should be visible");
    }

    @AfterEach
    public void tearDown() {
        driver.quit();
    }
}

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts	JUnit test runner initializes the test class	—	PASS
2	Browser opens ChromeDriver	Chrome browser window opens	—	PASS
3	Navigates to https://example.com	Browser loads the example.com homepage	—	PASS
4	PageFactory initializes elements annotated with @FindBy	submitButton WebElement is linked to element with id 'submit-btn'	—	PASS
5	Checks if submitButton is displayed	submitButton element is visible on the page	Assert that submitButton.isDisplayed() returns true	PASS
6	Test ends and browser closes	Chrome browser window closes	—	PASS

Failure Scenario

Failing Condition: The submit button is not visible on the page

Execution Trace Quiz - 3 Questions

What does PageFactory.initElements do in this test?

A It navigates to the URL

B It opens the browser window

C It links the WebElement fields to actual elements on the page

D It closes the browser

Key Result

Using PageFactory.initElements helps keep your test code clean by automatically linking WebElement fields to page elements, making tests easier to read and maintain.

Practice

1. What is the main purpose of using PageFactory.initElements() in Selenium Java?

easy

A. To execute JavaScript on the page

B. To start the WebDriver session

C. To initialize all WebElements annotated with @FindBy in a Page Object

D. To close the browser after test execution

Solution

1. Step 1: Understand the role of PageFactory

   PageFactory is used to initialize WebElements in Page Object Model classes.

2. Step 2: Purpose of initElements method

   The initElements method scans the class for @FindBy annotations and initializes those elements.

3. Final Answer:

   To initialize all WebElements annotated with @FindBy in a Page Object -> Option C

4. Quick Check:

   PageFactory.initElements initializes elements [OK]

Hint: Remember: initElements sets up @FindBy elements [OK]

Common Mistakes:

• Confusing initElements with WebDriver start or stop
• Thinking initElements executes JavaScript
• Assuming initElements closes the browser

2. Which of the following is the correct way to initialize PageFactory elements inside a constructor?

easy

A. PageFactory.initElements(driver, this);

B. PageFactory.initElements(this, driver);

C. initElements(driver, this);

D. PageFactory.startElements(driver, this);

Solution

1. Step 1: Recall the method signature

   The correct method call is PageFactory.initElements(WebDriver driver, Object page).

2. Step 2: Match parameters in constructor

   Inside the constructor, driver is passed first, then this refers to the current Page Object instance.

3. Final Answer:

   PageFactory.initElements(driver, this); -> Option A

4. Quick Check:

   Correct parameter order is driver, then this [OK]

Hint: Remember method signature: driver first, then page object [OK]

Common Mistakes:

• Swapping driver and this parameters
• Calling non-existent methods like startElements
• Omitting PageFactory class name

3. Given the following code snippet, what will be the output when loginButton.isDisplayed() is called after PageFactory initialization?

public class LoginPage {
  @FindBy(id = "loginBtn")
  private WebElement loginButton;

  public LoginPage(WebDriver driver) {
    PageFactory.initElements(driver, this);
  }
}

// In test method:
LoginPage page = new LoginPage(driver);
boolean visible = page.loginButton.isDisplayed();
System.out.println(visible);

medium

A. true if the element with id 'loginBtn' is visible on the page

B. Compilation error due to missing getter for loginButton

C. NullPointerException because loginButton is not initialized

D. false always because loginButton is private

Solution

1. Step 1: Check field visibility modifier

   The loginButton is declared private, so it cannot be accessed directly from outside the LoginPage class in the test method.

2. Step 2: Identify the compilation issue

   page.loginButton.isDisplayed() causes a compilation error; private fields require public getter methods for external access. PageFactory initializes the field but does not change its visibility.

3. Final Answer:

   Compilation error due to missing getter for loginButton -> Option B

4. Quick Check:

   Private fields need public getters for access [OK]

Hint: PageFactory initializes private fields but Java visibility rules still apply [OK]

Common Mistakes:

• Assuming direct access to private fields works after PageFactory init
• Expecting runtime false or NullPointerException instead of compile error
• Believing PageFactory overrides Java access modifiers

4. Identify the error in the following PageFactory initialization code:

public class HomePage {
  @FindBy(name = "searchBox")
  WebElement searchInput;

  public HomePage(WebDriver driver) {
    initElements(driver, this);
  }
}

medium

A. Incorrect locator strategy in @FindBy annotation

B. Constructor should not have parameters

C. WebElement should be private

D. Missing PageFactory class before initElements method call

Solution

1. Step 1: Check method call syntax

   The method initElements must be called with the class name PageFactory as PageFactory.initElements(...).

2. Step 2: Verify other code parts

   The locator strategy 'name' is valid, WebElement can be package-private, and constructor can have parameters.

3. Final Answer:

   Missing PageFactory class before initElements method call -> Option D

4. Quick Check:

   Always prefix initElements with PageFactory [OK]

Hint: Always call PageFactory.initElements, not just initElements [OK]

Common Mistakes:

• Calling initElements without PageFactory prefix
• Thinking locator strategy 'name' is invalid
• Assuming WebElement must be private
• Believing constructors cannot have parameters

5. You want to create a Page Object for a login page with username and password fields and a login button. Which of the following is the best practice for initializing elements using PageFactory?

hard

A. Declare WebElements with @FindBy, initialize them in constructor using PageFactory.initElements(driver, this), and keep elements private

B. Declare WebElements public without @FindBy, initialize manually in each test method

C. Use @FindBy annotations but do not call PageFactory.initElements anywhere

D. Initialize WebElements as static variables without PageFactory

Solution

1. Step 1: Understand Page Object best practices

   WebElements should be private and annotated with @FindBy for clear locators and encapsulation.

2. Step 2: Proper initialization

   PageFactory.initElements(driver, this) should be called in the constructor to initialize elements automatically.

3. Final Answer:

   Declare WebElements with @FindBy, initialize them in constructor using PageFactory.initElements(driver, this), and keep elements private -> Option A

4. Quick Check:

   Private elements + @FindBy + initElements in constructor = best practice [OK]

Hint: Use @FindBy + private + initElements in constructor [OK]

Common Mistakes:

• Making WebElements public exposing internals
• Skipping PageFactory.initElements call
• Initializing elements manually in tests
• Using static WebElements without context