1.
Hands on exploration of Page
Objects and Abstraction Layers with
Selenium WebDriver
A Half Day Tutorial
Alan Richardson
@eviltester
alan@compendiumdev.co.uk
www.SeleniumSimplified.com
www.EvilTester.com
www.CompendiumDev.co.uk
www.JavaForTesters.com

2.
2
Blogs and Websites
● CompendiumDev.co.uk
● SeleniumSimplified.com
● EvilTester.com
● JavaForTesters.com
● Twitter: @eviltester
Online Training Courses
● Technical Web Testing 101
Unow.be/at/techwebtest101
● Intro to Selenium
Unow.be/at/startwebdriver
● Selenium 2 WebDriver API
Unow.be/at/webdriverapi
Videos
youtube.com/user/EviltesterVideos
Books
Selenium Simplified
Unow.be/rc/selsimp
Java For Testers
leanpub.com/javaForTesters
Alan Richardson
uk.linkedin.com/in/eviltester
Independent Test Consultant
& Custom Training
Contact Alan
http://compendiumdev.co.uk/contact

3.
After gaining some experience of web automation tools, you start to realise that “yes, you have to
learn the API”, but the real challenge is modeling the application and building an abstraction layer
which supports different approaches to automation. And when we build an abstraction layer, we have
lots of options to choose between.
3
● Do you use the Page Factory?
● What counts as a page object?
● Should a page object offer logical functions like “loginAs” or does it only model the physical
world?
● How do we deal with navigation? Return page objects, or with a different set of objects?
● Do we need abstractions for Dom elements like input fields or is WebElement enough?
● When do we synchronise with WebDriverWait and when do we use SlowLoadableComponent?
● Should we build our own abstractions on top of SlowLoadableComponent?
By using a simple web application, we will use these, and other questions, to discuss and experiment
with, the most challenging parts of Web Automation – the modeling and construction of robust and
re-usable abstraction layers.
Existing practitioners, be prepared to discuss the choices you have made in the past, what worked,
and what didn’t, so that we can learn and possibly build on some of those decisions.
This is open to novices and experienced practitioners, but if you want to take part then make sure
you have a functioning Selenium WebDriver installation. All examples will be presented using Java,
but that doesn’t stop you writing experiments in Python, .Net, or whatever other language you favour.
Bring your laptop, and you’ll have the opportunity to explore different ways of building Page Objects
and abstraction layers.

4.
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Logistics & Plan
● 11:00 – 12:30 == 1.5
– Intro
– General Abstractions Overview
– Example Implementations & Discussions
– Exercise (till lunch)
● Given some scenarios, create some tests and abstraction
layers to support your tests
● 13:30 – 15:00 == 1.5
– Continue exercises and debrief
– Examples and Comparison with group
– Exercise (till end)
● Adjust your code, refactor to other approaches

5.
5
Code Examples & Slides
● http://unow.be/at/letstest2014sweden
● https://xp-dev.com/svn/AutomationAbstractions
● http://unow.be/at/letstest2014sweden

6.
6
Experiences Check
● Used WebDriver?
● What Languages?
● Abstraction Layers?
● Frameworks?
● Current setup
– Laptop With You?
– Ready to code?

7.
7
General Abstraction Concepts

8.
“I must create a system. or be
enslav'd by another Mans; I
will not reason & compare:
my business is to create”
8
William Blake,
Jerusalem: The Emanation of the Giant Albion
http://www.blakearchive.org/exist/blake/archive/object.xq?objectid=jerusalem.e.illbk.10&java=no

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What is Abstraction?
● Discuss

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Abstraction
● Modelling
● Separation of concerns
● Logical vs Physical
● Functional vs Structural
● Interfaces vs Implementations
● Data / Entities / Persistence
● Functionality / Task Flow
● Goals / Strategies
● Layers – GUI, DB, HTTP
● Etc.

11.
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Example Test Without Abstraction
@Before
public void startDriver(){
@Test
public void canCreateAToDoWithNoAbstraction(){
driver.get("http://todomvc.com/architecture-examples/backbone/");
int originalNumberOfTodos = driver.findElements(
By.cssSelector("ul#todo-list li")).size();
WebElement createTodo = driver.findElement(By.id("new-todo"));
createTodo.click();
createTodo.sendKeys("new task");
createTodo.sendKeys(Keys.ENTER);
assertThat(driver.findElement(
By.id("filters")).isDisplayed(), is(true));
int newToDos = driver.findElements(
By.cssSelector("ul#todo-list li")).size();
assertThat(newToDos, greaterThan(originalNumberOfTodos));
}
driver = new FirefoxDriver();
}
@After
public void stopDriver(){
driver.close();
driver.quit();
}
NoAbstractionTest.java

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Example Test With Abstraction
@Before
public void startDriver(){
@Test
public void canCreateAToDoWithAbstraction(){
TodoMVCUser user = new TodoMVCUser(driver, new TodoMVCSite());
user.opensApplication().and().createNewToDo("new task");
ApplicationPageFunctional page =
new ApplicationPageFunctional(driver, new TodoMVCSite());
assertThat(page.getCountOfTodoDoItems(), is(1));
assertThat(page.isFooterVisible(), is(true));
}
driver = new FirefoxDriver();
}
@After
public void stopDriver(){
driver.close();
driver.quit();
} NoAbstractionTest.java

13.
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Why Abstraction?
● Change implementations
● Single Responsibility – only changes when
necessary
● Makes automation readable and maintainable

14.
“...The name of the song is called ‘Haddocks' Eyes.’”
“Oh, that's the name of the song, is it?" Alice said, trying to feel
interested.
“No, you don't understand,” the Knight said, looking a little vexed.
“That's what the name is called. The name really is ‘The Aged
Aged Man.’”
“Then I ought to have said ‘That's what the song is called’?” Alice
corrected herself.
“No, you oughtn't: that's quite another thing! The song is called
‘Ways And Means’: but that's only what it's called, you know!”
“Well, what is the song, then?” said Alice, who was by this time
completely bewildered.
“I was coming to that,” the Knight said. “The song really is ‘A-sitting
On A Gate’: and the tune's my own invention.””
14
Lewis Carroll, Through The Looking Glass

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Common Abstraction Approaches

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Abstraction Layers Categorised
1) Data
– Generic Data Abstractions e.g. email, postcode
2) Physical
– Physical layout of your application e.g. pages,
components
– Navigation across pages
3) Domain
– Your application Entities domain e.g. user, account
4) Logical
– User actions, workflows

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Common Automation Abstractions
● Page Objects
● Element Abstractions: select, textbox, etc.
● Domain Objects
● Gherkin (Given/When/And/Then)
● Domain Specific Languages
● Any More?
– Create a List to discuss
– Any public examples?
– Any examples in the room that can be shared?

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Abstractions

19.
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Abstraction != Implementation
● Abstraction != Tool / Framework /
Implementation
● Gherkin != Cucumber
● Page Object != Page Factory
● DSL != Keyword Driven
If we want to get good at abstraction then we
need to model, split apart, and make the
relationships clear

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WebDriver as an Abstraction Layer
● Dom Abstraction
– WebElement
● Browser Abstraction
– WebDriver
● FireFox, Chrome, Remote etc.
● HTML Abstractions
– Cookies, Frames, etc.
● 'Support' classes augment WebDriver
– e.g. com.seleniumsimplified.selenium.support

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Model the application under test

22.
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Given an App – todomvc.com

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TodoMVC.com
Functional Overview
Demo
● Single Page App
● Shows Counts
● Data held in HTML5 local storage
● Create/Edit/Complete a 'todo'
● Clear Completed
● Filter active/completed/all
● Delete a todo

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Exercise Given an App –
todomvc.com
● What Abstractions might we build?
● What thoughts do we have?
● What underpins our analysis?
...Then Debrief

25.
Example Implementations Overview
25

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Page Objects
● The most obvious
automation abstraction
● What is it?
– A page? A Component?
● Experiences?
● Do web applications still
have pages?

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Page Object Design Decisions
● What methods does it have?
– Functional
● login(username, password),
● loginAs(user)
– Structural
● enterName(username), enterPassword(password),
clickLogin(), submitLoginForm(username, password)
● Does it expose elements or not?
– public WebElement loginButton;
– public WebElement getLoginButton();
– public clickLoginButton();

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Navigation Design Decisions
● Does a Page Object return other pages?
public IssueListPage submit(){
driver.findElement(By.id(“submit”)).click();
return new IssueListPage(driver);
}
● Pros?
● Cons?
● Experiences

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Page Objects
● What rules / guidelines / biases do you use for
page objects?

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Implementing Page Objects
● POJO
– Plain object, driver in constructor, methods use
driver.<method>
● Page Factory
– Annotated elements, lazy instantiation via reflection
● LoadableComponent
– Common interface (load, isLoaded), isLoaded
throws Error
● SlowLoadableComponent
– Common interface, waits for on isLoaded
● Other approaches?

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Implicit or Explicit Wait?
● Implicit Wait
driver.manage().timeouts().
implicitlyWait(15L, TimeUnit.SECONDS);
assertThat(driver.findElement(
By.id("filters")).isDisplayed()
, is(true));
● Explicit Wait
driver.manage().timeouts().
implicitlyWait(0L, TimeUnit.SECONDS);
WebDriverWait wait = new WebDriverWait(driver,15);
wait.until(ExpectedConditions.elementToBeClickable
(By.id("filters")));
Example: 'NoAbstractionTest.java'

32.
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Exercise Automate Scenarios
● Create a ToDo (check: count, text)
● Can Delete a ToDo (check: footers, count)
● Can Mark a ToDo as completed
● Can create a bunch of ToDos and delete, mark
as complete etc.
● Add additional checks as required
● Create Abstraction layers as appropriate
● We will discuss your compare your examples
with the group and the examples

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Example Implementations

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POJO
● 'ApplicationPage.java'
– Used in 'SequentialCreationOfTest.java'
– Not much refactoring in the example
● Simple Class
● WebDriver passed to constructor
● Composition of any components

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POJO Discussion
● Pros
● Cons

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Functional vs Structural
● Compare 'ApplicationPage' with 'ApplicationPageFunctional'
● Functional
– loginAs(username, password)
● Structural
– enterUsername
– enterPassword
– clickLoginButton
– submitLoginForm(username, password)
● Navigation
– Should Page Objects return Page Objects?

37.
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Functional Vs Structural Example
● One way of answering “what methods to put on
a page object”
– Is it functional / behavioural?
– Is it structural?
● Functional 'uses' Structural implementation
● See
– com.seleniumsimplified.page.functionalvsstructural

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Page Factory
● Compare ApplicationPageStructural with
ApplicationPageStructuralFactory
● Annotate fields with @FindBy
● Instantiate in constructor using
PageFactory.initElements
– Can create your own page factory initialiser

39.
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Page Factory Example
@FindBy(how = How.CSS, using="#todo-count strong")
private WebElement countElementStrong;
@FindBy(how = How.CSS, using="#todo-count")
private WebElement countElement;
@FindBy(how = How.CSS, using="#filters li a")
List<WebElement> filters;
@FindBy(how = How.ID, using="clear-completed")
List<WebElement> clearCompletedAsList;
@FindBy(how = How.ID, using="clear-completed")
WebElement clearCompletedButton;
public ApplicationPageStructuralFactory(WebDriver driver, TodoMVCSite todoMVCSite) {
PageFactory.initElements(driver, this);
this.driver = driver;
...

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Page Factory Discussion
● Pros
● Cons

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Loadable Component
● Extends LoadableComponent
– Get
● If isLoaded, return this
● Else load()
● Check isLoaded()
● Implement load
– Add any synchronisation in load to wait for the
loading. Exit only when 'loaded'.
● Implement isLoaded
– Check, and throw Error if not loaded

42.
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Loadable Component Example
● Compare ApplicationPageStructural with
ApplicationPageStructuralLoadable

43.
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Loadable Component Discussion
● Pros
● Cons

44.
SlowLoadable Component Example
44
● Extends SlowLoadableComponent
● Constructor has to additionally call
– super(new SystemClock(), 10);
– Where 10 is a timeout # of seconds
● get()
– If isLoaded then return this Else load
– While not loaded{ wait for 200 millseconds}
● Implement load and isLoaded
– But can remove sync loops from load

45.
SlowLoadable Component Example
45
● Compare ApplicationPageStructural with
ApplicationPageStructuralSlowLoadable

46.
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SlowLoadable Component
Discussion
● Pros
● Cons

47.
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Fluent Page Objects
● Methods return the page object or other objects
– e.g. get() on LoadableComponent
● Instead of
– void clickDeleteButton();
– PageObject clickDeleteButton();
● Syntactic sugar methods:
– and(), then(), also()
● Work well at high levels of abstraction
– See SequentialCreationOfTestFluentSubset and
ApplicationPageFunctionalFluent
– Compare ApplicationPageFunctional with ...Fluent

48.
● Direct in Test Navigation Options
● Instantiate new pages based on test flow
48
– Navigation as side-effect, may have to bypass 'get'
– Loadable pages, non-loadable, support classes
● Page Object methods might return other Pages
– e.g. a method on the login page might be
● MyAccountPage clickLogin();
– Returns a new page
● void clickLogin();
● We might use navigation objects
– direct, or Path based (current page → desired
page)
● Navigate.to(MyAccountPage.class)
● Jump.to(MyAccountPage.class)

49.
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Possible Domain Abstractions
● Logical Objects
– ToDo
– ToDoList
● Physical Objects
– LocallyStoredToDo
● Actors
– User
● Environment
– Site
– Implementation

50.
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Page Objects & Domain Objects
● Instead of
– todoMVC.enterNewToDo(“New Item”)
● We could have have
– ToDoItem newItem = new ToDoItem(“New Item”);
– todoMVC.enterNewToDo(newItem);
● Discuss
● See code in DomainBasedTest

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Domain Objects That Span Logical
& Physical
e.g. User
● user.createNewToDo(“new item”)
● user.createNewToDo(newItem)
● Discuss
● See use in NoAbstractionTest

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Element Abstractions

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Element Abstractions
● Existing support: Select,
● Possible: TextBox, Checkbox, TextBox, File etc.
● Can enforce Semantics
– Checkbox: isChecked, check(), uncheck(), toggle()
– TextBox: clear(), enterText()
– etc.
● Pass back from Page Objects into test?
● e.g. Checkbox in ElementWrapperTest
– new CheckBox(driver, By);
– new CheckBox(element)

54.
54
Element Abstraction Examples
public interface Checkbox {
public boolean isChecked();
public Checkbox check();
public Checkbox uncheck();
public Checkbox toggle();
}
● Would you include 'toggle'?

55.
Element Abstraction Pros and Cons
55
● May have to create a custom page factory
● Can help 'restrict' code i.e. check or uncheck,
rather than click, enforces 'semantics'
● I make sure to return WebElement so that I can
go beyond the abstraction layer if I need to. Not
required if it is just a WebElement wrapper.

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Component Abstractions
● Components on the screen
– e.g. ComponentTest
● e.g. VisibleToDoEntry, Filters, Footer, Header,
VisibleToDoList, etc.
● Could have 'functional' representation for
repeated items e.g. login forms
● Could have 'structural' representation
● Likely use : page object composition

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Component Abstraction Example
page.getToDoEntryAt(todoMVC.getCountOfTodoDoItems()-1).
markCompleted();
● See 'ComponentTest.java'
– ApplicationPageStructuralComponents (compare
with ApplicationPageStructural
– VisibleToDoEntry
● (this also uses Element Abstraction)

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Gherkin as an abstraction layer
Feature: We can create and edit To Do lists in ToDoMvc
We want to amend todos in ToDoMVC because that is
the set of exercises on the abstraction tutorial
Scenario: Create a ToDo Item
Given a user opens a blank ToDoMVC page
When the user creates a todo "new task"
Then they see 1 todo item on the page
● Implement steps using highest appropriate
abstraction layer
● CucumberJVM as 'DSL implementor'
● 'Expressibility' vs 'Step Re-use'
● See todomvc.feature and ToDoMvcSteps

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Additional Debrief
● Did anyone do anything different?
● Any other abstraction approaches you used?
● Anything else to add?

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Final Exercise Section
● Continue to automate the site
● Build abstraction layers to cover the
functionality
● Experiment with additional approaches
mentioned that you haven't used
● Or, use code and amend and experiment

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Final Debrief

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My bias model has Driver as core
● Driver
– Build around that so instantiate any page or
component as required at any time
● Synchronisation
– To make sure that the desired object is available
and ready for use (as defined by synchronisation)
● Navigation
– Implicit (via actions)
– Explicit
● Open/jump (via driver.get)
● To (state model from current, to desired)

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Biases
● Examine some common biases and discuss
pros/cons based on experience

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Are there rights and wrongs?
● Right / Wrong?
● Decisions?
● Project/Team/Organisation Standards?

65.
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Should we add asserts into
abstraction layers?
● e.g.

66.
Should Page Objects consume and
66
return domain objects?
● e.g.
– loginAs(user)
– List<User> getUsersList()

67.
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Should Page Objects return
WebElements?

68.
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Decisions
● The 'limits' and overlap of Abstraction Layers
● Build it now, or 'refactor to' later
● How much change is anticipated?
– To which layer? GUI, Business domain, Workflow?
● Who is working with the automation code?
– Skill levels? Support needed?
● How/When with the automation execute?

69.
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Decisions
● The 'limits' and overlap of Abstraction Layers
● Build it now, or 'refactor to' later
● How much change is anticipated?
– To which layer? GUI, Business domain, Workflow?
● Who is working with the automation code?
– Skill levels? Support needed?
● How/When with the automation execute?

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“To the creative mind there is
no right or wrong. Every
action is an experiment, and
every experiment yields its
fruit in knowledge.”
The Illuminatus Trilogy
Robert Anton Wilson

71.
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Other Useful Links
● Jeff “Cheezy” Morgan – page-object ruby gem,
data_magic gem and stareast code
– https://github.com/cheezy?tab=repositories
● Marcus Merrell
– Self-Generating Test Artifacts for Selenium/WebDriver
– https://www.youtube.com/watch?v=mSCFsUOgPpw

72.
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Blogs and Websites
● CompendiumDev.co.uk
● SeleniumSimplified.com
● EvilTester.com
● JavaForTesters.com
● Twitter: @eviltester
Online Training Courses
● Technical Web Testing 101
Unow.be/at/techwebtest101
● Intro to Selenium
Unow.be/at/startwebdriver
● Selenium 2 WebDriver API
Unow.be/at/webdriverapi
Videos
youtube.com/user/EviltesterVideos
Books
Selenium Simplified
Unow.be/rc/selsimp
Java For Testers
leanpub.com/javaForTesters
Alan Richardson
uk.linkedin.com/in/eviltester
Independent Test Consultant
& Custom Training
Contact Alan
http://compendiumdev.co.uk/contact

73.
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Notes: Install app locally
● https://github.com/tastejs/todomvc/commit/f57e0b773db14f094ef09274af90042f83328412
● https://github.com/tastejs/todomvc/archive/f57e0b773db14f094ef09274af90042f83328412.zip
● Point Site url to file:// location unarchive and run tests – absolute links won't work without a
server