Use native extensions

To provide your native extension to application developers, you package all the necessary files into an ActionScript Native Extension (ANE) file by following these steps:

1. Build the extension’s ActionScript library into a SWC file.

2. Build the extension’s native libraries. If the extension has to support multiple platforms, build one library for each target platform.

3. Create a signed certificate for your extension. If the extension is not signed, Flash Builder displays a warning when you add the extension to your project.

4. Create an extension descriptor file.

5. Include any external resources for the extension, such as images.

6. Create the extension package using the Air Developer Tool. For more information, see the Adobe AIR documentation.

For detailed information on packaging ActionScript extensions, see Developing Native Extensions for Adobe AIR.

You include an ActionScript Native Extension (ANE) file in the project’s build path the same way as you would include a SWC file.

1. In Flash Builder, when you create a Flex mobile project, select the Native Extensions tab in the Build Paths settings page.

   You can also add extensions from the Project Properties dialog box by selecting Flex Build Path.

2. Browse to the ANE file or the folder containing the ANE files to add to the project. When you add an ANE file, the extension ID is added to the project’s application descriptor file (project name-app.xml) by default.

Flash Builder displays an error symbol for the added extension in the following scenarios:

• The Adobe AIR runtime version of the extension is later than the application’s runtime version.

• The extension does not include all the selected platforms that the application is targeting.

When you use the Export Release Build feature to export the mobile application, the extensions used in the project are included within the application package by default.

To change the default selection, follow these steps:

1. In the Export Release Build dialog box, select the Native Extensions tab under Package Settings.

2. The ActionScript native extension files referenced in your project are listed, indicating if the ANE file is used in the project or not.

   If the ANE file is used in the project, it is selected by default in the application package.

   If the ANE file is included in the project but not used, the compiler does not recognize the ANE file. It is then not included in the application package. To include the ANE file in the application package, do the following:

   1. In the Project Properties dialog box, select Flex Build Packaging and the required platform.

   2. Select the extensions that you want to include in the application package.

The Adobe AIR SDK contains a bundled iOS SDK version. The bundled iOS SDK version is specific to the Adobe AIR version. For example, Adobe AIR 3.1 contains iOS4 SDK, and Adobe AIR 3.4 contains iOS5 SDK.

If you want to use features from an iOS SDK higher than the bundled version, you can configure the supported iOS SDK version externally.

The supported iOS SDK versions are as follows:

When you use multiple native extensions in your iOS application, there can be common symbol names that are used among the native extensions. These symbol name conflicts can cause issues during packaging (error message appears). And in some cases, cause the application to crash during runtime.

To ensure that this error does not occur, follow these steps:

When you select this option, the ADT package command -hideAneLibSymbols is set to yes, and any unintended symbol conflict issues are resolved. For more information, see ADT package command.