O'Reilly logo

Developing iOS Applications with Flex 4.5 by Rich Tretola

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Chapter 1. Hello World

This section will walk you through building your first iOS application using Adobe Flash Builder 4.5. If you don’t have Flash Builder 4.5, you can get a trial from Adobe at http://www.adobe.com/products/flashbuilder/.

Now that you have Flash Builder 4.5 installed, open it and let’s get started.

Create a Flex Mobile Project

Create a new Flex Mobile Project by choosing File→New→Flex Mobile Project, as shown in Figure 1-1.

Create a Flex Mobile Project
Figure 1-1. Create a Flex Mobile Project

This will open the New Flex Mobile Project wizard, which will walk you through the rest of the project creation process. The first screen you will be presented with will allow you to set the project name, location, and Flex SDK. Enter the name HelloWorld as the Project name and leave the other settings to their defaults. Click Next, as shown in Figure 1-2.

Project name and location
Figure 1-2. Project name and location

The second screen in the new project wizard is where you can select settings specific to the target platform. You will see the options for Apple iOS, BlackBerry Tablet OS, and Google Android. Please select Apple iOS. You also have the option of three different application types, which are Blank, View-Based Application, and Tabbed Application. For this first project, please select View-Based Application, as shown in Figure 1-3, and leave the other settings to their defaults.

Select application template
Figure 1-3. Select application template

Next, click on the Platform settings tab. Within this tab, you will be able to select the iOS platform that your application will target. For the purposes of this exercise, leave the Target devices as All, as shown in Figure 1-4. Click Next.

Platform settings→Target devices
Figure 1-4. Platform settings→Target devices

The next screen allows for the configuration of an application server and output folder. For this project we will not be using an application server, so leave it set to None/Other, and click Next as shown in Figure 1-5.

Server settings
Figure 1-5. Server settings

The last screen that you will see is the Build Paths screen where you will be able to set your Application ID. This setting is very important, as this will identify your application in the App Store. To ensure that your application has a unique identifier, the reverse domain naming convention works best. Figure 1-6 shows the value of com.domain.mobile.HelloWorld as the application ID. By replacing the word domain with a domain that you own, you can ensure that your application ID is unique. Complete this step and click Finish.

Application ID
Figure 1-6. Application ID

Flash Builder will now create your new project, and by default the HelloWorldHomeView.mxml will be created and opened in the workspace along with the HelloWorld.mxml main application file. This is shown in Figure 1-7.

A new project has been created
Figure 1-7. A new project has been created

Let’s update the contents of the HelloWorldHomeView.mxml by adding a Label:

<?xml version="1.0" encoding="utf-8"?>
<s:View xmlns:fx="http://ns.adobe.com/mxml/2009"
          xmlns:s="library://ns.adobe.com/flex/spark" title="HomeView">
          <!-- Place non-visual elements (e.g., services, value objects) here -->

    <s:Label text="Hello World" fontSize="24"
                horizontalCenter="0" verticalCenter="0"/>


Before running an application for the first time, you will need to set up either a simulator environment or a device for your testing.

Testing with adl

You can test some basic functionality of your application within Flash Builder using the adl simulator—however, for full testing and packaging of your iOS application, you will need to purchase an Apple developer certificate and an Apple device. In this example, I will be using an iPod touch running the latest iOS operating system.

To test with adl, simply click on the play button and choose Run As Mobile Application, as shown in Figure 1-8. Next, select Apple iOS as the target platform; and On desktop and Apple iPhone 3GS as the Launch Method, as shown in Figure 1-9. Now click Run and you will see the application running within adl, as shown in Figure 1-10.

Run As Mobile Application
Figure 1-8. Run As Mobile Application
Configure runtime environment
Figure 1-9. Configure runtime environment
Running within adl
Figure 1-10. Running within adl

Preparing to Test on an iOS device

To test on an iOS device, you will first need to purchase a developer certificate from Apple for $99 by visiting https://developer.apple.com.

Download and Install Certificate

Once you have your certificate, you can download the developer_identity.cer file from the iOS Provisioning Portal, as shown in Figure 1-11, and import it. On OSX, you can import into Keychain Access application by double clicking on the developer_identity.cer as shown in Figure 1-12. Now, simply right-click on the private key within Keychain Access and export the certificate as a .p12, as shown in Figures 1-13 and 1-14.

Download certificate
Figure 1-11. Download certificate
Import into Keychain Access
Figure 1-12. Import into Keychain Access
Export certificate
Figure 1-13. Export certificate
Save as a .p12
Figure 1-14. Save as a .p12

Add a Device

You will also need to have a device registered with Apple. You can add a device by registering it within the Devices section of the iOS Provisioning Portal, as shown in Figure 1-15.

Add a device
Figure 1-15. Add a device

Create a new App ID

Now that you have a device added, you will need to create a new App ID within the App IDs area of the iOS Provisioning Portal. Click on the App IDs menu on the left side of the iOS Provisioning Portal, and then click on the New App ID button and complete the form, as shown in Figure 1-16.

Add new App ID
Figure 1-16. Add new App ID

Create a Provisioning Certificate

To create a provisioning certificate, click on the Provisioning link on the left side of the iOS Provisioning Portal and then click on the New Profile button. Complete the form and click the Submit button, as shown in Figure 1-17. Next, download the newly created certificate as shown in Figure 1-18 (note that you may need to refresh your browser to get the download button enabled).

Create a Provisioning Profile
Figure 1-17. Create a Provisioning Profile
Download provisioning certificate
Figure 1-18. Download provisioning certificate

Testing on an iOS device

If you have completed the steps to create a certificate and provisioning certificate, you can now test your application on an iOS device. To do this, right-click on your project name and choose Run As→Run Configurations to open the configuration dialog box, as shown in Figure 1-19. Once the dialog box opens, set the Target Platform as Apple iOS and choose “On device” as the Launch method. You will now need to configure the package settings by clicking on the Configure link, as shown in Figure 1-20, and selecting your p12 certificate file and mobileprovisioning files, as shown in Figure 1-21.

Run As→Run Configurations
Figure 1-19. Run As→Run Configurations
The Run Configurations dialog box
Figure 1-20. The Run Configurations dialog box
Configure certificate and provisioning file
Figure 1-21. Configure certificate and provisioning file

Now that you have your certificates defined, you can click the Run button, which will compile your application to an .ipa file for installation on an iOS device.


Adobe has provided two options for your testing. You can either choose Standard or Fast as your Packaging method.

Figure 1-22 shows the application being compiled. Once the compile has completed, click on the link shown in Figure 1-23 to show the new compiled file and then click on that file to load the application via iTunes. Figure 1-24 shows the HelloWorld-debug application loaded into iTunes, and Figure 1-25 shows HelloWorld-debug installed on an iPod. Figure 1-26 shows the application running on an iPod.

Compiling an iOS application
Figure 1-22. Compiling an iOS application
Compiling complete
Figure 1-23. Compiling complete
HelloWorld-debug loaded into iTunes
Figure 1-24. HelloWorld-debug loaded into iTunes
HelloWorld-debug installed on iPod
Figure 1-25. HelloWorld-debug installed on iPod
HelloWorld-debug running on iPod
Figure 1-26. HelloWorld-debug running on iPod

Debugging on an iOS device

Now that you have created your Hello World application and run it via the Run Configurations window, you may wish to debug your application. Fortunately for you, the workflow for debugging a Flex Mobile application is the same as debugging any other Adobe Flex or Adobe AIR application.

Update the HelloWorld.mxml file to include a creationComplete handler as shown below:

<?xml version="1.0" encoding="utf-8"?>
<s:ViewNavigatorApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
               import mx.events.FlexEvent;

               protected function viewnavigatorapplication1_creationCompleteHandler(event:FlexEvent):void
                     // TODO Auto-generated method stub
                     trace("hello world");

          <!-- Place non-visual elements (e.g., services, value objects) here -->

We will now need to toggle a breakpoint within the application on line 14 to demonstrate a debugging session. To do this, right-click on line 14 within Flash Builder and select Toggle Breakpoint from the context menu. Figure 1-27 shows this process. A small blue dot will appear in the gutter, showing the breakpoint is enabled.

Toggle a breakpoint
Figure 1-27. Toggle a breakpoint

We are now ready to debug this application. To do this, right-click on the HelloWorld.mxml file within the Package Explorer and select Debug As→Mobile Application, as shown in Figure 1-28. Since this is the first time debugging this application, the Debug Configurations window will open. To debug this using the Flash builder emulator, select “On device” as the Launch method and select a device from the dropdown menu, as shown in Figure 1-29.

Debug As Mobile Application
Figure 1-28. Debug As Mobile Application
The Debug Configurations window
Figure 1-29. The Debug Configurations window

Just as before when you ran your application, your application will compile to an .ipa file, which you will need to load to your device via iTunes. Flash Builder will wait while you load the application on the device. Once you have loaded the application and launched it, you will need to enter the IP address of your host machine where Flash Builder is running. See Figures 1-30 and 1-31. Once the application is running, Flash Builder will ask you to switch to the debug perspective.

When asked if you would like to switch to the Flash Builder debug perspective, select “Yes” (see Figure 1-32.) Figure 1-33 shows the application paused on line 14 within Flash Builder’s debug perspective. You can see the trace message within the console panel. To allow the application to complete, click the Resume button.

Congratulations, you have just completed your first Flash Builder debug session for an iOS Flex Mobile application.

Waiting for Debugger Connection window
Figure 1-30. Waiting for Debugger Connection window
Enter the IP address to connect to debugger
Figure 1-31. Enter the IP address to connect to debugger
Confirming the switch to debug perspective
Figure 1-32. Confirming the switch to debug perspective
Hello World application paused on line 14
Figure 1-33. Hello World application paused on line 14

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required