BANGALORE, INDIA: One good feature in Adobe's AIR, the platform for developing rich Internet apps is a database engine that runs within AIR's runtime environment. Since all the database files are stored locally, there is no need of an external database connection.

This also implies that persistent application data can be stored conveniently on the local drive. The local database is stored as a single file in the computer's file system. The runtime is responsible for creation, retrieval and manipulation of data in this database file. In the following implementation, we will be using synchronous mode of execution to create RIAs with AIR.

Implementation
Let's start with installation of AIR SDK. This can be downloaded from 'www.adobe.com or you can also get it from this issue's DVD. Once extracted to a folder, set the PATH environment variable. This can be done by adding reference of extracted folder to it. In our case, we added the following path in the end of PATH environment variable 'C:\AdobeAIRSDK\bin'.

The bin folder present in SDK contains ADL and ADT tools. AIR debug launcher or ADL is used to run applications without packaging them, whereas AIR developer tool is for packaging your application as an AIR file for distribution. One more important file that we would be using in this implementation is 'AIRaliases.js' present in 'C:\AdobeAIRSDK \frameworks\libs\air' folder.

This file provides alias definition that allows one to run 'ActionScript' runtime class i.e. air.FileStream, air.SQLDatabase etc. To use this file, one needs to add following script reference in HTML page:

Start with creating a folder that contains three files: XML file (pcquest.xml), HTML file (pcquest.html) and AIRaliases.js file as explained above. We will start with the applications descriptor file (pcquest.xml). Here is the content of this file along with explanation: