iPhone UI Automation and the Page Object pattern

At the time when I was actively contributing to Selenium I used it only in conjunction with FitNesse and could therefore not directly apply the Page Object pattern. However, one of the key principles was for me the abstraction of the UI elements by creating UI maps which contain simple mappings of logical names to XPath path expressions.

The Page Object pattern defines the same abstraction: Define and use UI elements only in one module, and provide only service functions to the test cases.
Instead of diving deeper into theoretical details here is an example:

#import "Common.js"

function LoginView() {
    this.loginCells = window.tableViews()[0].cells();
    this.loginField = this.loginCells["loginFieldCell"].textFields()["loginField"];
    this.passwordField = this.loginCells["passwordFieldCell"].secureTextFields()["passwordField"];
    this.loginButton = this.loginCells["loginButtonCell"].buttons()["loginButton"];

}

LoginView.prototype.login = function(user, password) {
    this.loginField.setValue(user);
    this.passwordField.setValue(password);
    this.loginButton.tap();
}

LoginView.prototype.waitForDisappear = function() {
    this.loginField.waitForInvalid();
}

So a test looks like as follows:

#import "../TestControllers/LoginView.js"
#import "../TestControllers/UserDetailView.js"

var loginView = new LoginView();
var userDetailView;

test("Valid login leads to user detail page", function(t, a) {
    loginView.login("andras_hatvani","password");
    loginView.waitForDisappear();
    userDetailView = new UserDetailView();
    userDetailView.assertUserData("andras_hatvani", "Andras Hatvani");
},options)};

Although I use tuneup_js as test framework in this example, it could be Jasmine or a custom framework.
Important is that I could formulate the tests in a business-like language i.e. in an own DSL, thus it is not only straightforward to write, but also to read. Furthermore, if the UI changes, then I only need to adapt one single unit, namely LoginView.js to make my tests run again.