Eric Feminella

I have received quite a few emails since the release of AIR 1.0 and Flex 3.0 regarding the AIR Cairngorm API which I developed last year. In the time since I have been working primarily with a modified version of AIR Cairngorm which I used on a number of successful real world AIR applications, however I simply have not had the time to document and refactor for general use until recently.

In case you are not familiar with AIR Cairngorm it is an open source project built on top of Adobe Cairngorm which provides a framework for working with the Adobe AIR SQLite API while building an application with Cairngorm.

AIR Cairngorm is built around the SQLService class which essentially wraps the AIR SQL APIs to provide a uniform interface which can be utilized as a service, much in the same way one would work with RPC services in a typical Cairngorm application. SQLService provides an API for both synchronous and asynchronous implementations.

In the time since the initial development and release of AIR Cairngorm, which was during the early alpha releases of AIR, there has been many changes to the SQL APIs in AIR. In addition I have also developed some new best practices for working with Adobe AIR and Cairngorm, all of which I tried to roll into this latest release where possible.

The following is a brief description of the current AIR Cairngorm API:

AIRServiceLocator: The AIRServiceLocator is a sub class of Cairngorm ServiceLocator, therefore it inherits the same API as ServiceLocator while also adding additional support for working with local databases via the getSQLService and hasSQLService methods.
AIRServiceLocator

SQLService: The SQLService class essentially wraps the SQLStatement and SQLConnection classes. SQLService allows developers to create an mxml implementation defined on a Cairngorm ServiceLocator just as one would with typical RPC services (e.g. HTTPServices, WebService etc.)
SQLService

ISQLResponder: ISQLResponder provides a consistent API from which asynchronous SQLStatement execution results and faults can be handled. ISQLResponder is very similar to IResponder in that it defines both a result and fault handler however with a slightly different signature which is specific to a SQLStatement result / fault, (i.e. strongly typed parameters).
ISQLResponder

SQLStatementHelper: SQLStatementHelper is an all static utility class which facilitates substituting tokens in a SQL statement with arbitrary values.
SQLStatementHelper

I have also created a custom version of my Cairngen project specifically targeting AIR Cairngorm code generation. In addition I will be making some future updates to AIR Cairngorm which will include support for various other AIR APIs in Cairngorm, so stay tuned.

Below I have provided downloads to the source, binary, air.cairngen and asdocs as well as asynchronous and synchronous example projects:
source
binary
examples
asdoc
air cairngen
air cairngorm (all)

At some point when developing an application with ActionScript 3 you may need to pass a …(rest) parameter to a subsequent function call, and although at first this may appear to be pretty straightforward, doing so will not produce the results one might expect.

For example, consider the following method doSomething which accepts a single …rest parameter:

Let’s say we also have another function we need to invoke called doSomethingElse which accepts a …(rest) parameter as well:

Now suppose we need to pass the ...(rest) parameter from the doSomething function to the doSomethingElse function. The result would be as follows:

So what went wrong? What happens is the original …rest parameter (passed to doSomething) is now being passed as a single parameter of type Array to the subsequent function (doSomethingElse), not as an Array of individual arguments as you may have expected.

This can easily be resolved by using Function.apply(); as can be seen in the following:

What we are doing is applying the call to the doSomethingElse function with the original rest parameter as if we were invoking the function directly. So keep this in mind should you ever need to pass a …rest parameter to a subsequent function.

I recently made a number of updates to my collections API which include some minor changes to the existing code as well as a few additional classes and interfaces which have been added.

The most significant updates involve three additional operations which have been added to the IMap interface which are as follows:

I have also added two new additional IMap implementations to the collections API; LocalPersistenceMap, which can be utilized to provide an IMap implementation into a local SharedObject and ResourceMap which allows developers to work with a ResourceBundles via an IMap implementation. All IMap implementations; HashMap, ResourceMap and LocalPersistenceMap have been updated to implement the new operations.

The IIterator interface has been renamed to Iterator. In addition the remove() operation has been omitted in order to enforce that a concrete implementations can not modify an aggregate. Additionally, ICollectionViewSortHelper has been renamed to CollectionSortUtil.

Some design decisions worth mentioning involve the inclusion of multiple IMap implementations; HashMap, ResouceMap and LocalPersistanceMap. Initially I identified an AbstractMap from which these classes would extend, however I realize some developers may want to minimize dependencies as much as possible therefore I decided to simply have each concrete map implement the IMap interface rather than extend an abstract map implementation.

The source, binary and ASDocs for the new Collections API can be downloaded here.

The Collections API is published under the MIT license.

Since the initial release of Cairngen 1.0 there has been an amazing amount of interest in the project and your feedback has been very encouraging. In addition I have received a number of extremely valuable customizations from community members, many of which have made it into subsequent releases.

In order to provide a solid foundation to help facilitate a collaborative Open Source initiative for the Cairngen Project I have decided to move the project to Google Code.

Moving Cairngen to Google Code allows for a number of significant development benefits for the Cairngorm Community. This includes regular development updates, access to all releases, availability of all source code revisions, better documentation, defect lists, feature requests and much more.

I am currently accepting requests for new contributors so if you feel you have added new functionality which would provide benefit to the project visit the Become a Contributor page. All comments on the project are welcome and encouraged. In addition I strongly recommend the if you have any issues with Cairngen, especially environmental issues you should log them to the Issues Page.

Along with the new Cairngen Google Code Project I have also released Cairngen 2.1.1 which aligns the source project with the new SVN repository.

So go check out all of the new information on Cairngen at the new Cairngen Project Home.

When building localized Flex applications with ResourceBundle there are a few tricks you may not be aware of which can come in handy should you need them.

I have had quite a few people ask how multiline values can be specified in a properties file. This is a pretty common question and luckily the answer is very simple: backslash (\).

For example, suppose you have a properties file which contains a string resource with a really long value, like a paragraph. Typically the property value will just be one really long String on one line. However you can use the backslash (\) character to continue the value on multiple lines in order to make the properties file more legible, such as in the following example:

So if you have properties with very long values remember to use backslash (\) to help clean up your resources.

example

When developing browser based Flex applications, SharedObject provides just about everything one needs to facilitate local persistence of application data. While being somewhat restricted by certain rules governed by the Flash Player Security Model, in general, it provides a rather simple solution for most needs.

The data property of a SharedObject provides read/write access to the underlying data which is persisted to the SharedObject. Personally, I prefer to have a consistent API available when working with dynamic objects, thus I developed the IMap interface.

LocalPersistenceMap provides an IMap implementation into the data property of a SharedObject instance. It allows clients to work with the underlying data of a SharedObject just as one would with a HashMap, ResourceMap, etc.

Below is a basic example which demonstrates how LocalPersistenceMap can be utilized to provide an IMap implementation into a SharedObject:

The LocalPersistenceMap constructor creates a reference to a local SharedObject based on the specified identifier and optional local path. A reference to the underlying SharedObject can also be retrieved via the sharedObjectInstance accessor.

In addition to the new LocalPersistenceMap, I have also packaged the Collections API which can be downloaded here. Complete documentation and code examples for the Collections API are also available here.