AdvancED Flex 4

CHAPTER 8

286

• Fine-grained: For remoting destinations, you could create an include list by using multiple

include-method tags (or using the exclude-method tag). Such lists will ensure that only the

included methods are callable on the remote destinations. Calling any other method would

cause an error.

Authentication mechanisms can be custom or basic. This implies that you could leverage your existing

authentication systems using the custom route.

Following is an example of a destination-level configuration that uses custom authentication:

<destination id="ro">

<security>

<security-constraint>

<auth-method>Custom</auth-method>

<roles>

<role>roUser</role>

</roles>

</security-constraint>

</security>

</destination>

HTTPService, WebService, and RemoteObject support passing and invalidation of login credentials

using the setCredentials and the logout methods, respectively. You can also pass credentials to

remote services using setRemoteCredentials.

A simple example of setCredentials with RemoteObject is as follows:

var myRemoteObject:RemoteObject = new RemoteObject();

myRemoteObject.destination = "SecureDestination";

myRemoteObject.setCredentials("userName", "myPassword");

myRemoteObject.send({param1: 'param1Value'});

Implementing custom security and setting up fine-grained access control can be tedious, but with BlazeDS

you can utilize such constructs without adding any additional overhead.

Summary

This chapter rapidly covered a fair number of topics related to data services.

The chapter started with an overview of the data services architecture. Then you explored the steps

involved in installing data services and configuring it. Subsequently you built an example application and

saw data services in action.

The review of the features of data services topics included Java to Flex serialization, asynchronous

communication, support for additional data types, custom adapters, connection scalability, data push over

sockets, and transactions. Server-side proxy and its usage for HTTP-based calls as well as web services

were also illustrated.

Data services positions the Adobe Flex and AIR technologies as viable choices for some serious

applications for the present and the future. In the age of event-driven, real-time, responsive rich systems,

where the Web is transforming itself into a read-write media network, technologies as these are bound to

shine.