Page object model in selenium - selenium

Question

Can anyone please resolve the issue in the below post.
Selenium Framework Page Object Model and Page Navigation
I am not able to resolve the null pointer exception issue when a page returns an object of other page. Can anyone please tell what is the exact way of doing it. As explained in the above link, it's not clear how the error is resolved.

Answer 1

I will try illustrating PageFactory example using 3 different classes types.
Base Class- Has configuration setting like driver declaration
POM Class- Contains the POM objects for a single page
Test Class-Class containing test steps
BaseClass Example
public class BaseClass {
public WebDriver driver=null;
public BaseClass() throws MalformedURLException {
driver=new firefoxDriver();
driver.manage().window().maximize();
driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
driver.get(baseURL);
}
POM Class example
//Class1
public class WebshopHomePage {
WebDriver driver;
public WebshopHomePage(WebDriver driver){
this.driver=driver;
}
#FindBy(how=How.LINK_TEXT,using="Log in")//Identifying page elements
WebElement loginLink;
public void clickLoginLink(){
loginLink.click();
}
}
//Class2
public class SignInSignUpPage {
WebDriver driver;
public SignInSignUpPage(WebDriver driver){
this.driver=driver;
}
#FindBy(how=How.ID,using="Email")
WebElement emailID;
}
TestClass Example
public class WebShopSignInTest extends BaseClass {
#Test
public void testSteps() {
System.out.println("I'm in teststeps!!");
WebshopHomePage wshpObj=PageFactory.initElements(driver,WebshopHomePage.class);//Assigning POM class1 objects to driver
wshpObj.clickLoginLink();
SignInSignUpPage signInSignUpPageObj=PageFactory.initElements(driver, SignInSignUpPage.class);//Assigning POM class2 objects to driver
signInSignUpPageObj.enterCredsSubmit(userID, passw0rd);
}

Answer 2

package org.pom;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.support.FindBy;
import org.openqa.selenium.support.PageFactory;
public class GoogleHomePageObjects
{
public GoogleHomePageObjects(WebDriver driver)
{
PageFactory.initElements(driver, this);
}
#FindBy(name="q")
public WebElement txtSearch;
#FindBy(name="btnG")
public WebElement btnSearch;
#FindBy(linkText="Selenium - Web Browser Automation")
public WebElement lnkSelenium;
public void searchGoogle(String SearchText)
{
txtSearch.sendKeys(SearchText);
btnSearch.click();
}
public SeleniumPageObjects clickSelenium()
{
lnkSelenium.click();
return new SeleniumPageObjects(driver); //Here is the issue and i am getting error
}
}
//test class 2
package org.pom;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.support.FindBy;
import org.openqa.selenium.support.PageFactory;
public class SeleniumPageObjects{
public SeleniumPageObjects(WebDriver driver)
{
PageFactory.initElements(driver, this);
}
#FindBy(linkText="Download")
public WebElement lnkDownload;
#FindBy(xpath=".//*[#id='header']/h1/a")
public WebElement lnkHome;
public void clickDownloads()
{
lnkDownload.click();//Here it throws null pointer excception
}
public void clickHome()
{
lnkHome.click();
}
}
Below is my main class:
package org.pom;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
public class GoogleSearchTest
{
public static void main(String[] args) throws InterruptedException
{
System.setProperty("webdriver.gecko.driver","D:\\Desktop\\Selenium\\Jars\\geckodriver-v0.11.1-win64\\geckodriver.exe");
WebDriver driver=new FirefoxDriver();
driver.get("http://www.google.com");
GoogleHomePageObjects page=new GoogleHomePageObjects(driver);
page.searchGoogle("Selenium");
Thread.sleep(4000);
SeleniumPageObjects selPage=page.clickSelenium();
Thread.sleep(4000);
selPage.clickDownloads();
Thread.sleep(4000);
selPage.clickHome();
}
}

Answer 3

In the below example, We have created a Login class , Home class, and a Test class ...
It is not necessary to create one class for one page may be you can group the functionality or modules based on your convenience...
Summary:-
Created Login Class with all the required objects...and the loginas method should return the homepage class.....
public class LoginPage {
private final WebDriver driver;
public LoginPage(WebDriver driver) {
this.driver = driver;
// Check that we're on the right page.
if (!"Login".equals(driver.getTitle())) {
// Alternatively, we could navigate to the login page, perhaps logging out first
throw new IllegalStateException("This is not the login page");
}
}
// The login page contains several HTML elements that will be represented as WebElements.
// The locators for these elements should only be defined once.
By usernameLocator = By.id("username");
By passwordLocator = By.id("passwd");
By loginButtonLocator = By.id("login");
public LoginPage typeUsername(String username) {
driver.findElement(usernameLocator).sendKeys(username);
// Return the current page object as this action doesn't navigate to a page represented by another PageObject
return this;
}
public LoginPage typePassword(String password) {
driver.findElement(passwordLocator).sendKeys(password);
// Return the current page object as this action doesn't navigate to a page represented by another PageObject
return this;
}
public HomePage submitLogin() {
// This is the only place that submits the login form and expects the destination to be the home page.
// A seperate method should be created for the instance of clicking login whilst expecting a login failure.
driver.findElement(loginButtonLocator).submit();
// Return a new page object representing the destination. Should the login page ever
// go somewhere else (for example, a legal disclaimer) then changing the method signature
// for this method will mean that all tests that rely on this behaviour won't compile.
return new HomePage(driver);
}
// Conceptually, the login page offers the user the service of being able to "log into"
// the application using a user name and password.
public HomePage loginAs(String username, String password) {
// The PageObject methods that enter username, password & submit login have already defined and should not be repeated here.
typeUsername(username);
typePassword(password);
return submitLogin();
}
}
2. Created Homepage class , I have added only a sample verification method here , may be you can add methods as per your application needs...
class HomePage {
private final WebDriver driver;
public HomePage(WebDriver driver) {
this.driver = driver;
// Check that we're on the right page.
if (!"HOME".equals(driver.getTitle())) {
// Alternatively, we could navigate to the login page, perhaps
// logging out first
throw new IllegalStateException("This is not the home page");
}
}
// below method is just a sample method
public HomePage verifyRecords() {
/// your homepage validation
return null;
}
}
Now we are going to see how to put the above class together and make it work as per your requirement...
class Test {
public static void main(String[] args) {
LoginPage login = new LoginPage(new FirefoxDriver());
// login and verify records in home page
login.loginAs("myname", "pass##").verifyRecords();
}
}
In this line login.loginAs("", "").verifyRecords(); we are calling a method from login class and the method that is being called would return HomePage class....
You can create any no of pom classes and return it like the above......Like create some thing like dashboard and return it from homepage class
How returning page works :-
login.loginAs("myname", "pass##").verifyRecords();
In the above code once this login.loginAs("myname", "pass##") snippet executes , it will complete the login action and returns this method submitLogin(); which in turns returns new HomePage......
Here once execution of login.loginAs("myname", "pass##") is done it will become new Homepageobject..... Javacompiler is smart enough to manipulate that and provides the Homepageobject's methods once you put a dot after login.loginAs("myname", "pass##").