Unable to initialise PageFactory for PageObject

[ashishkumar1000]

I have updated the java-client jar and tried to initialise PageFactory as mention below.

PageObject PageObject1 = PageFactory.initElements(new AppiumFieldDecorator(driver),PageObject.class);

But I am getting type mismatch error.
Is there something I am missing ???

[amedvedjev]

same problem

[TikhomirovSergey]

Hi! Let see this (is taken from here https://github.com/SeleniumHQ/selenium/blob/master/java/client/src/org/openqa/selenium/support/PageFactory.java):

   * @param pageClassToProxy A class which will be initialised.
   * @return An instantiated instance of the class with WebElement and List<WebElement> fields proxied
   */
  public static <T> T initElements(WebDriver driver, Class<T> pageClassToProxy)

  /**
   * As
   * {@link org.openqa.selenium.support.PageFactory#initElements(org.openqa.selenium.WebDriver, Class)}
   * but will only replace the fields of an already instantiated Page Object.
   * 
   * @param driver The driver that will be used to look up the elements
   * @param page The object with WebElement and List<WebElement> fields that should be proxied.
   */
  public static void initElements(WebDriver driver, Object page)


  /**
   * Similar to the other "initElements" methods, but takes an {@link ElementLocatorFactory} which
   * is used for providing the mechanism for fniding elements. If the ElementLocatorFactory returns
   * null then the field won't be decorated.
   * 
   * @param factory The factory to use
   * @param page The object to decorate the fields of
   */
  public static void initElements(ElementLocatorFactory factory, Object page)


  /**
   * Similar to the other "initElements" methods, but takes an {@link FieldDecorator} which is used
   * for decorating each of the fields.
   * 
   * @param decorator the decorator to use
   * @param page The object to decorate the fields of
   */
  public static void initElements(FieldDecorator decorator, Object page)

You should istantiate your "page object" before
PageFactory.initElements

PageObject po = new PageObject();
PageFactory.initElements(new AppiumFieldDecorator(driver),po)

Please pay attention: PageFactory.initElements is "void".

[amedvedjev]

"You should istantiate your "page object" before " - before what?

let say in test class we have following

Abstract Page:

public abstract class Page {
protected AppiumDriver driver;
public Page(AppiumDriver driver) {
this.driver = driver;
}
}

Test Page:

public class FirstPage extends Page {
@findby(id = "something")
private List elemList;
public FirstPage(AppiumDriver driver) {
super(driver);
}
//some staff
}

Test class:

private FirstPage firstPage;
@test
public void doTest() {
// was before: firstPage = PageFactory.initElements(driver, FirstPage.class);
PageFactory.initElements(new AppiumFieldDecorator(driver), FirstPage.class);
}

[TikhomirovSergey]

Ok.
Let see two different examples below:

public class Test {

    public static class PageObject {

        private final WebDriver driver;

        @FindBy(className = "android.widget.TextView")
        private WebElement element;

        public PageObject(WebDriver driver){
            this.driver = driver;
        }

        public void click(){
            element.click();
        }
    }

    private PageObject po;

    @Before
    public void setup() throws Exception {
        File appDir = new File("src/test/java/io/appium/java_client");
        File app = new File(appDir, "ApiDemos-debug.apk");
        DesiredCapabilities capabilities = new DesiredCapabilities();
        capabilities.setCapability(MobileCapabilityType.BROWSER_NAME, "");
        capabilities.setCapability(MobileCapabilityType.DEVICE_NAME, "Android Emulator");
        capabilities.setCapability(MobileCapabilityType.PLATFORM_NAME, "Android");
        capabilities.setCapability(MobileCapabilityType.APP, app.getAbsolutePath());
        /**
         * Attention please
         */
        po = PageFactory.initElements(new AppiumDriver(new URL("http://127.0.0.1:4723/wd/hub"), capabilities), PageObject.class);

    }

    @org.junit.Test
    public void test() {
        po.click();     
    }

    @After
    public void tearDown() throws Exception {
        po.driver.quit();
    }   

}

If you use PageFactory only with @findby, there is nothing to change. Your example will work well without AppiumFieldDecorator.

But... Are you sure that all your browser locators are suitable for Android\iOS native\hybrid app?

/**
 * 
 * Imagine, that we have application API Demos with the same UI
 * But different locators (browser/Android) 
 *
 */
public class Test2 {

    public static class PageObject {

        private final WebDriver driver;

        @FindBy(className = "someDOMClass")
        @AndroidFindBy(className = "android.widget.TextView")
        private WebElement element;

        public PageObject(WebDriver driver){
            this.driver = driver;
            /**
             * Attention please
             */
            PageFactory.initElements(new AppiumFieldDecorator(driver), this);
        }

        public void click(){
            element.click();
        }
    }

    private PageObject po;

    @Before
    public void setup() throws Exception {
        File appDir = new File("src/test/java/io/appium/java_client");
        File app = new File(appDir, "ApiDemos-debug.apk");
        DesiredCapabilities capabilities = new DesiredCapabilities();
        capabilities.setCapability(MobileCapabilityType.BROWSER_NAME, "");
        capabilities.setCapability(MobileCapabilityType.DEVICE_NAME, "Android Emulator");
        capabilities.setCapability(MobileCapabilityType.PLATFORM_NAME, "Android");
        capabilities.setCapability(MobileCapabilityType.APP, app.getAbsolutePath());
        /**
         * Attention please
         */
        po = new PageObject(new AppiumDriver(new URL("http://127.0.0.1:4723/wd/hub"), capabilities));

    }

    @org.junit.Test
    public void test() {
        po.click();     
    }

    @After
    public void tearDown() throws Exception {
        po.driver.quit();
    }

AppiumFieldDecorator decorates Webelement-fields which marked by @AndroidFindBy/@iOSFindBy. This decorator supports @findby too.

[amedvedjev]

thanks!

[amedvedjev]

Sergey,

still not clear how to initiate pages one by one inside test class?

I can't start this with every page change.
/**
* Attention please
*/
po = PageFactory.initElements(new AppiumDriver(new URL("http://127.0.0.1:4723/wd/hub"), capabilities), PageObject.class);

mine example:

Abstract Page:

public abstract class Page {
protected AppiumDriver driver;
public Page(AppiumDriver driver) {
this.driver = driver;
PageFactory.initElements(new AppiumFieldDecorator(driver), this);
}
}

Test Page:

public class FirstPage extends Page {
@findby(id = "something")
private List elemList;
public FirstPage(AppiumDriver driver) {
super(driver);
}
//some staff
}

Test class:

public class testDoTests extends AppiumSetup {
private FirstPage firstPage;
private SecondPage secondPage;
@test
public void doTest1() {
firstPage = PageFactory.initElements(driver, FirstPage.class); // CRASH HERE!
//do some tests on first page
secondPage = PageFactory.initElements(driver, SecondPage.class);
//do some tests on second page
}
}

Appium Setup class:

public class AppiumSetup {
protected static AppiumDriver driver = null;
driver = new AppiumDriver(new URL("http://0.0.0.0:4723/wd/hub"), capabilities);
}

[TikhomirovSergey]

Please, let me see stacktrace.

[amedvedjev]

java.lang.RuntimeException: java.lang.InstantiationException: com.cardola.tests.page.android.KeywordPage
at org.openqa.selenium.support.PageFactory.instantiatePage(PageFactory.java:136)
at org.openqa.selenium.support.PageFactory.initElements(PageFactory.java:66)
at com.cardola.tests.test.android.testKeywordPage.testKeywordPage(testKeywordPage.java:22)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:84)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:714)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
at org.testng.TestRunner.privateRun(TestRunner.java:767)
at org.testng.TestRunner.run(TestRunner.java:617)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:348)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:343)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:305)
at org.testng.SuiteRunner.run(SuiteRunner.java:254)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1224)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1149)
at org.testng.TestNG.run(TestNG.java:1057)
at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:111)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:204)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:175)
at org.testng.RemoteTestNGStarter.main(RemoteTestNGStarter.java:125)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: java.lang.InstantiationException: com.cardola.tests.page.android.KeywordPage
at java.lang.Class.newInstance0(Class.java:342)
at java.lang.Class.newInstance(Class.java:310)
at org.openqa.selenium.support.PageFactory.instantiatePage(PageFactory.java:133)
... 32 more

[TikhomirovSergey]

It looks strange....

    public static abstract class AbstractPageObject {

        protected final WebDriver driver;       
        public AbstractPageObject(WebDriver driver){
            this.driver = driver;
            /**
             * Attention please
             */
            PageFactory.initElements(new AppiumFieldDecorator(driver), this);
        }
    }   

    public static class PageObject extends AbstractPageObject {

        public PageObject(WebDriver driver) {
            super(driver);
        }

        @FindBy(className = "android.widget.TextView")
        private WebElement element;

        public void click(){
            element.click();
        }
    }

    protected static AppiumDriver driver;

    @Before
    public void setup() throws Exception {
        File appDir = new File("src/test/java/io/appium/java_client");
        File app = new File(appDir, "ApiDemos-debug.apk");
        DesiredCapabilities capabilities = new DesiredCapabilities();
        capabilities.setCapability(MobileCapabilityType.BROWSER_NAME, "");
        capabilities.setCapability(MobileCapabilityType.DEVICE_NAME, "Android Emulator");
        capabilities.setCapability(MobileCapabilityType.PLATFORM_NAME, "Android");
        capabilities.setCapability(MobileCapabilityType.APP, app.getAbsolutePath());

        driver = new AppiumDriver(new URL("http://127.0.0.1:4723/wd/hub"), capabilities);       
    }

    @org.junit.Test
    public void test() {
        PageObject po = PageFactory.initElements(driver, PageObject.class);
        po.click();     
    }

}

This code works!

[TikhomirovSergey]

I could reproduce the similar exception on this code:

    public static abstract class AbstractPageObject {

        protected final WebDriver driver;       
        public AbstractPageObject(WebDriver driver){
            this.driver = driver;
            /**
             * Attention please
             */
            PageFactory.initElements(new AppiumFieldDecorator(driver), this);
        }
    }   

                        //!!!
    public static abstract class PageObject extends AbstractPageObject {

        public PageObject(WebDriver driver) {
            super(driver);
        }

        @FindBy(className = "android.widget.TextView")
        private WebElement element;

        public void click(){
            element.click();
        }
    }

    protected static AppiumDriver driver;

    @Before
    public void setup() throws Exception {
        File appDir = new File("src/test/java/io/appium/java_client");
        File app = new File(appDir, "ApiDemos-debug.apk");
        DesiredCapabilities capabilities = new DesiredCapabilities();
        capabilities.setCapability(MobileCapabilityType.BROWSER_NAME, "");
        capabilities.setCapability(MobileCapabilityType.DEVICE_NAME, "Android Emulator");
        capabilities.setCapability(MobileCapabilityType.PLATFORM_NAME, "Android");
        capabilities.setCapability(MobileCapabilityType.APP, app.getAbsolutePath());

        driver = new AppiumDriver(new URL("http://127.0.0.1:4723/wd/hub"), capabilities);       
    }

    @org.junit.Test
    public void test() {
        PageObject po = PageFactory.initElements(driver, PageObject.class);
        po.click();     
    }

java.lang.RuntimeException: java.lang.InstantiationException
at org.openqa.selenium.support.PageFactory.instantiatePage(PageFactory.java:136)
at org.openqa.selenium.support.PageFactory.initElements(PageFactory.java:66)
at io.appium.java_client.Test2.test(Test2.java:68)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.InstantiationException
at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.openqa.selenium.support.PageFactory.instantiatePage(PageFactory.java:131)
... 26 more

[TikhomirovSergey]

How does your code fall? See listing from Selenium:

  private static <T> T instantiatePage(WebDriver driver, Class<T> pageClassToProxy) {
    try {
      try {
        Constructor<T> constructor = pageClassToProxy.getConstructor(WebDriver.class);
        return constructor.newInstance(driver);
      } catch (NoSuchMethodException e) {
        return pageClassToProxy.newInstance(); //cause
      }
    } catch (InstantiationException e) {
      throw new RuntimeException(e); //thrown
    } catch (IllegalAccessException e) {
      throw new RuntimeException(e);
    } catch (InvocationTargetException e) {
      throw new RuntimeException(e);
    }
  }
}

[amedvedjev]

so you reproduced same problem with:

at org.openqa.selenium.support.PageFactory.instantiatePage(PageFactory.java:136)
at org.openqa.selenium.support.PageFactory.initElements(PageFactory.java:66)

Questions:

• Do you want me to try make code changes as with your succeeded example?
• or do i need wait for a fix?

[TikhomirovSergey]

Please, make sure that your target class is not abstract and has constructor like this: new PageObject(driver)

Anyway, the best way to use AppiumDecorator is (if it really need to be used, I wrote above):

po = new PageObject(some params);
PageFactory.PageFactory.initElements(new AppiumFieldDecorator(driver), po);

The reason I will describe over five minutes.

[TikhomirovSergey]

So, let see this code:

   * @see FindBy
   * @see CacheLookup
   * @param driver The driver that will be used to look up the elements
   * @param pageClassToProxy A class which will be initialised.
   * @return An instantiated instance of the class with WebElement and List<WebElement> fields proxied
   */
  public static <T> T initElements(WebDriver driver, Class<T> pageClassToProxy) {
    T page = instantiatePage(driver, pageClassToProxy); (1)
    initElements(driver, page); (2)
    return page;
  }

At (1) constructor of page object will populate fields.

You attempted to use this

public Page(AppiumDriver driver) {
this.driver = driver;
PageFactory.initElements(new AppiumFieldDecorator(driver), this);
}
}

If there is a field
@AndroidFindBy(someLocator)
//iOSFildBy(someLocator)
WebElement semeElement

at (2) it turns into null because of

   * 
   * @param driver The driver that will be used to look up the elements
   * @param page The object with WebElement and List<WebElement> fields that should be proxied.
   */
  public static void initElements(WebDriver driver, Object page) {
    final WebDriver driverRef = driver;
    initElements(new DefaultElementLocatorFactory(driverRef), page); //(!!!)
 //All webelement fields which 
//are not annotated by @FindBy turn into null here
//This is made by Selenium developers. It is so frustrating. 
  }