Saturday 23 July 2016

Page Object Model in Selenium


Simple Page Object Model with example


In this example we will see a very simple Page Object Model example. To explain we have taken Google application and created Base Page, Sign In page and Create Account page.

Page Object Model Introduction

Page Object Model Framework has now a days become very popular test automation framework in the industry and many companies are using it because of its easy test maintenance and reduces the duplication of code.
The main advantage of Page Object Model is that if the UI changes for any page, it don’t require us to change any tests, we just need to change only the code within the page objects (Only at one place). Many other tools which are using selenium, are following the page object model.

In the above screen shot, we have first identified the locators and defined it on the top after the class. In this way we can achieve readability of test scripts and we can easily identify locators and change them if needed at only one place.
Page Object model is writing all the functionalities / reusable components of a page that we want to automate in a separate class. Say now if we consider four pages as Home page, Login page, Create Account and Forgot password page etc.

As per Google Wiki Page Object
"Within your web app’s UI there are areas that your tests interact with. A Page Object simply models these as objects within the test code. This reduces the amount of duplicated code and means that if the UI changes, the fix need only be applied in one place."

For the above pages we will create classes as HomePage.class, LoginPage.class, CreateAccountPage.class and ForgotPasswordPage.class. In each class we will identify and write reusable methods which are specific to a page.

Here in The first page 'google home page' which will have many options like Search, Sign In, +You, Images, privacy etc links. based on the user action it navigates to respective page. Now all functionalities that we want to automate should have reusable methods/components for each page.

Now as our main page is google page we can navigate to other pages by clicking on any link from the google page. When ever we are navigating to other page, we need to return that page object. Else Return the current page object as this action doesn't navigate to a other page represented by another Page Object

The Page Object model provides the following advantages.

1. There is clean separation between test code and page specific code such as locators (or their use if you’re using a UI map) and layout.
2. There is single repository for the services or operations offered by the page rather than having these services scattered through out the tests.

In both cases this allows any modifications required due to UI changes to all be made in one place. Useful information on this technique can be found on numerous blogs as this ‘test design pattern’ is becoming widely used. We encourage the reader who wishes to know more to search the internet for blogs on this subject. Many have written on this design pattern and can provide useful tips beyond the scope of this user guide. To get you started, though, we’ll illustrate page objects with a simple example.

Example: Lets us take a simple login example: /***
* Tests login functionality
*/
public void loginTestCase() {
driver.navigate().to(URL);
driver.findElement(By.name("signIn")).click();
driver.findElement(By.id("username")).sendKeys("testuser");
driver.findElement(By.id("password")).sendKeys("testpassword");
driver.findElement(By.name("loginbtn")).click();

WebDriverWait wait = new WebDriverWait(driver, 10);
wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("profile")));
String Expected=driver.findElement(By.id("message")).getText();
Assert.assertEquals(Expected, "Welcome");


}

If you observe the above test, there is no separation of test and test locators. If this is the case, in future if the UI changes, it must be changed in multiple places. It will also become difficult to identify where these locators are used as the chances of locators are being used in multiple tests are more.

We will try to rewrite the above example by implementing the page object model:/***
* Tests login functionality
*/
public void loginTestCase() {
// To go to home page
homePage.gotoHomePage();
//To click on SignIn link
accountLoginPage = homePage.clickOnSignIn()
//To verify if user is navigated to sign-in page
Assert.assertTrue(accountLoginPage.verifyPage());
//Login to the account
accountLoginPage.userLogin(username,password);
//To verify if user is navigated to user home page after successfull login
Assert.assertTrue(userHomePage.verifyPage());
}

In the above test, we have not used any locators. It is completely separated by driver.findElement 's, waits, exceptions and no static values in the code etc.We will be working only with the methods which are defined in multiple pages. Based on test, we will navigate to the required page and access those page methods.

Simple Page Object Model Framework example

Steps to Create a Simple Page Object Model. The structure of the sample project should look like in the screen shot below



Step 1: Create the Test Setup class

This the main class for page object model, where we will create Webdriver object based on the browser type passed as a parameter in textng.xml file. We will also need to pass the base page application URL in testng.xml as parameter.

In this example we have taken only two browsers the default Firefox and chrome browser. To initiate Chrome browser, we need to set the System Property by providing the chromedriver exe path.
We need to create a method to return Webdriver 'driver' where this is used for test execution.
Below is the example TestBaseSetup.class file

package com.pack.base;

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.testng.annotations.AfterClass;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Parameters;

public class TestBaseSetup {

private WebDriver driver;
static String driverPath = "D:\\chromedriver\";
public WebDriver getDriver()
{
        return driver;

}

private void setDriver(String browserType, String appURL)
{
   switch (browserType) {
case "chrome":
driver = initChromeDriver(appURL);
break;
case "firefox":
driver = initFirefoxDriver(appURL);
break;
default:
System.out.println("browser : " + browserType
+ " is invalid, Launching Firefox as browser of choice..");

driver = initFirefoxDriver(appURL);

}

}

private static WebDriver initChromeDriver(String appURL) {
System.out.println("Launching google chrome with new profile..");
System.setProperty("webdriver.chrome.driver", driverPath
+ "chromedriver.exe");

WebDriver driver = new ChromeDriver();
driver.manage().window().maximize();
driver.navigate().to(appURL);

return driver;

}

private static WebDriver initFirefoxDriver(String appURL) {
System.out.println("Launching Firefox browser..");
WebDriver driver = new FirefoxDriver();
driver.manage().window().maximize();
driver.navigate().to(appURL);
return driver;

}

@Parameters({ "browserType", "appURL" })
@BeforeClass

public void initializeTestBaseSetup(String browserType, String appURL) {
try {

setDriver(browserType, appURL);

} catch (Exception e) {
System.out.println("Error....." + e.getStackTrace());

}

}



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

}

Step 2: Now We will create Page Object classes. For each page we will create a separate class with constructor. We identify the locators and keep all together on just below the class. This will help us to re-use the locators for multiple methods and the main important is, we can easily find the locator and change if required.

We need to identify and list of all the possible functionalities on this page and we should write methods in such a way they are re-used. When ever there is a method to click on a button or link, we should return driver object of that page.

We will look into the below example. For method SignInBtn, we are returning after clicking on Sign In button as it is redirecting to sign in page.

BasePage.class

package come.pack.common.pageobjects;

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

public class BasePage {

protected WebDriver driver;
private By signInButton = By.linkText("Sign in");

public BasePage(WebDriver driver) {
this.driver = driver;

}

public SignInPage clickSignInBtn() {
System.out.println("clicking on sign in button");
WebElement signInBtnElement=driver.findElement(signInButton);
if(signInBtnElement.isDisplayed()||signInBtnElement.isEnabled())
signInBtnElement.click();
else System.out.println("Element not found");
return new SignInPage(driver);

}

public void clickImagesLink() {
//It should have a logic to click on images link
//And it should navigate to google images page

}
public String getPageTitle(){

String title = driver.getTitle();

return title;

}

public boolean verifyBasePageTitle() {

String expectedPageTitle="Google";

return getPageTitle().contains(expectedPageTitle);

}


}

In the below SignInpage.class, we have methods to click on create account and sign in button. We are just verifying an error in sign in page for now in this example.

SignInPage.class

package come.pack.common.pageobjects;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement

public class SignInPage {
private WebDriver driver;
private By headerPageText = By.cssSelector(".hidden-small");
private By createAccountLink = By.id("link-signup");
private By emailTextBox = By.id("Email");
private By passwordTextBox = By.id("Passwd");
private By loginBtn = By.id("signIn");
private By errorMsgTxt = By.id("errormsg_0_Passwd");

public SignInPage(WebDriver driver) {
this.driver=driver;

}

public String getSignInPageTitle() {
String pageTitle = driver.getTitle();
return pageTitle;
}

public boolean verifySignInPageTitle() {
String expectedTitle = "Sign in - Google Accounts";
return getSignInPageTitle().contains(expectedTitle);

}

public boolean verifySignInPageText() {
WebElement element = driver.findElement(headerPageText);
String pageText = element.getText();
String expectedPageText = "Sign in with your Google Account";
return pageText.contains(expectedPageText);

}

public CreateAccountPage clickonCreateAnAccount() {
WebElement element=driver.findElement(createAccountLink);
if(element.isDisplayed()||element.isEnabled())
element.click();
return new CreateAccountPage(driver);

}
public boolean verifySignIn() {
enterUserName("test");
enterPassword("pass");
clickOnSignIn();

return getErrorMessage().contains("incorrect");

}

public void enterUserName(String userName) {

WebElement emailTxtBox = driver.findElement(emailTextBox);

if(emailTxtBox.isDisplayed())

emailTxtBox.sendKeys(userName);

}



public void enterPassword(String password) {

WebElement passwordTxtBox = driver.findElement(passwordTextBox);

if(passwordTxtBox.isDisplayed())

passwordTxtBox.sendKeys(password);

}

public void clickOnSignIn() {

WebElement signInBtn = driver.findElement(loginBtn);

if(signInBtn.isDisplayed())

signInBtn.click();

}


public String getErrorMessage() {

String strErrorMsg = null;

WebElement errorMsg = driver.findElement(errorMsgTxt);

if(errorMsg.isDisplayed()&&errorMsg.isEnabled())

strErrorMsg = errorMsg.getText();

return strErrorMsg;

}

}


CreateAccountPage.class

package come.pack.common.pageobjects;

import org.openqa.selenium.By;

import org.openqa.selenium.WebDriver;

import org.openqa.selenium.WebElement;


public class CreateAccountPage {

private WebDriver driver;

private By headerPageTxt = By.cssSelector(".signuponepage.main.content.clearfix>h1");

public CreateAccountPage(WebDriver driver) {

this.driver=driver;

}

public String getPageTitle() {

String title = driver.getTitle();

return title;

}

public boolean verifyPageTitle() {

String pageTitle = "Create your Google Account";

return getPageTitle().contains(pageTitle);

}

public boolean verifyCreateAccountPageText() {

WebElement element = driver.findElement(headerPageTxt);

String pageText ="Create your Google Account";

return element.getText().contains(pageText);

}

public void createAccount() {

//need to write steps for creating an account

}



}

Step 3: Now we will see how to write Tests for the above pages. For all the page Objects, we will now create Tests for each page. Which will help us in easy maintainability. if there is any change in the UI, we can simply change in one Page one place. We will see first example test for "BasePageTest.class".

In the below example we verifying home page by taking the title. We have written a method in BasePage and we are just calling it here.

'package com.pack.common.tests;

import org.openqa.selenium.WebDriver;
import org.testng.Assert;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;
import com.pack.base.TestBaseSetup;
import come.pack.common.pageobjects.BasePage;

public class BasePageTest extends TestBaseSetup{

private WebDriver driver;

@BeforeClass
public void setUp() {
driver=getDriver();

}


@Test

public void verifyHomePage() {

System.out.println("Home page test...");

BasePage basePage = new BasePage(driver);

Assert.assertTrue(basePage.verifyBasePageTitle(), "Home page title doesn't match");

}


}


We will look into the next test 'SignInPageTest'. In the below test, we are verifying page title, page text, and Sign in functionality. For all these verifications we have defined methods in SignInPage class which we are calling from tests.

package com.pack.common.tests;
import org.openqa.selenium.WebDriver;
import org.testng.Assert;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;
import com.pack.base.TestBaseSetup;
import come.pack.common.pageobjects.BasePage;
import come.pack.common.pageobjects.SignInPage;
public class SignInPageTest extends TestBaseSetup{
private WebDriver driver;
private SignInPage signInPage;
private BasePage basePage;

@BeforeClass
public void setUp() {

driver=getDriver();

}

@Test

public void verifySignInFunction() {

System.out.println("Sign In functionality details...");

basePage = new BasePage(driver);

signInPage = basePage.clickSignInBtn();

Assert.assertTrue(signInPage.verifySignInPageTitle(), "Sign In page title doesn't match");

Assert.assertTrue(signInPage.verifySignInPageText(), "Page text not matching");

Assert.assertTrue(signInPage.verifySignIn(), "Unable to sign in");

}


}

Now the create test 'CreateAnAccountTest'. Now we should be able to understand the verification that we are doing in the below test.

package com.pack.common.tests;

import org.openqa.selenium.WebDriver;

import org.testng.Assert;

import org.testng.annotations.BeforeClass;

import org.testng.annotations.Test;
import com.pack.base.TestBaseSetup;
import come.pack.common.pageobjects.BasePage;

import come.pack.common.pageobjects.CreateAccountPage;

import come.pack.common.pageobjects.SignInPage;

public class CreateAnAccounTest extends TestBaseSetup {

private WebDriver driver;

private SignInPage signInPage;

private BasePage basePage;

private CreateAccountPage createAccountPage;



@BeforeClass

public void setUp() {

driver=getDriver();

}



@Test

public void verifyCreateAnAccounPage() {

System.out.println("Create An Account page test...");

basePage = new BasePage(driver);

signInPage = basePage.clickSignInBtn();

createAccountPage = signInPage.clickonCreateAnAccount();

Assert.assertTrue(createAccountPage.verifyPageTitle(), "Page title not matching");

Assert.assertTrue(createAccountPage.verifyCreateAccountPageText(), "Page text not matching");

}
public void verifySignInFunction() {

}

}


Step 4: We are done with Base Setup, Page Objects creation, Tests creation. Now we will execute them using 'testng.xml' file. We will add the classes which we want to test.


Remember we need to pass the parameters 'browserType' and 'appURL' for the base Setup class.


<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">

<suite name="Page Object test example">

<parameter name="appURL" value="https://www.google.co.in/"/>

<parameter name="browserType" value="firefox"/>

<test name="sample test">

<classes>

<class name="com.pack.common.tests.HomePageTest"/>

<class name="com.pack.common.tests.SignInPageTest"/>

<class name="com.pack.common.tests.CreateAnAccounTest"/>

</classes>

</test>

</suite>


The above Page Object Model framework is the simple one without using any Build tools, Loggers, Listeners and Utilities. In the next coming post we will add all these things and design a Robust Page Object Model Framework which are used in the Industry.


The below are the list of things which are commonly used in the Real time Page Object Model Framework.

1. Selenium Webdriver with Java

2. Maven Build Tool

3. TestNG (We will user TestNG Listeners also)

4. Log4j

5. Eclipse IDE