In this tutorial I will show how to create an iOS native extension for Adobe AIR. My extension enables sending an e-mail by invoking MFMailComposeViewController on iOS. This way you can send an e-mail without leaving you app, attachments are supported, too.

Grab the source from github: iOS In-app mail Native Extension for Adobe AIR

How to use iOS mail extension

Create an intance of class pl.randori.air.nativeextensions.ios.MailExtension and call method
sendMail(subject:String, messageBody:String, toRecipients:String, ccRecipients:String = ””, bccRecipients:String = ””, attachmentsData:Array = null):void

MailExtension dispatches MainExtensionEvent.MAIL_COMPOSER_EVENT to let you know what’s going on. You will be notified if the user has sent the mail, saved it, canceled, etc.
Also there will be notifications WILL_SHOW_MAIL_COMPOSER and WILL_HIDE_MAIL_COMPOSER so you could know when the mail composer is shown and dismissed.
This can be used to stop / resume task in AIR while the mail composer is present on the screen

Creating an native extension for Adobe AIR requires some iOS/Objective-C knowledge so don’t worry if not everything’s clear at the beginning.

I divided the process of development to three steps

1. Creating a native library in Xcode
2. Creating an ActionScript library which will act as a middleware between Adobe AIR and iOS
3. Creating an example Adobe AIR app

My development environtment was Flash Builder 4.5 with Flex SDK 4.5.1 and AIR SDK 3.1 and Xcode 4.2 and iOS SDK 5. Flash Builder 4.5 doesn’t support native extensions development, so I’ve used ANT to compile and package everything.

Before starting be sure to merge Flex SDK with Adobe AIR SDK.

Creating the native library in Xcode for AIR an iOS

A native library can be written in Objective-C, C/C++ or Java depending on the target platform. Currently extensions for iOS, Android, BlackBerry PlayBook and AIR TV are supported. The library exposes an API that the Adobe AIR application can use, which can include functionalities that are not available in the current release of Adobe AIR or make use of performance of native code (math, physics computations; image processing, etc.).

On iOS Adobe AIR cannot access to such APIs as: Game Center, In-App Purchase, Twitter or Bluetooth. With native extensions we can create a fully featured iOS app.

In Xcode create a new static library project and set the project setting as follows: