One of the new features we included into WebORB version 4.4 for .NET (and very soon in WebORB for Java) is the support for multi-client publish/subscribe messaging. If you’re not familiar with publish/subscribe, it is a simple, yet very powerful data exchange pattern. A computer program may be in one of the two roles (or in both) : a publisher or a subscriber. Publishers send messages to the server and the server routes the messages to all the subscribers. Subscribers can subscribe with some rules: for instance to receive messages which have a specific header. WebORB provides support for this type of integration for a variety of clients, including Flex, AIR, JavaScript, Java (both standalone and Android), Silverlight, Windows Phone and iOS. Some clients, for instance, Flex and AIR, include APIs in their SDKs enabling client-side support for publish/subscribe. For other client types, we provide libraries with the requiring APIs. Additionally, WebORB simplifies the problem of heterogeneous client integration. That means, clients from different environments can easily exchange messages with each other. For example, Android apps can send and receive message to/from Windows Phone or iOS apps. Message handling is also configurable. Published messages can be routed to (or received from) MSMQ, ActiveMQ or any NMS destination.

To make it easier to get started with publish/subscribe, we included messaging code generators into the latest release of WebORB.  The code generators create complete projects with all the source code demonstrating both message publishing and subscription for Flex, JavaScript, Java, Windows Phone and Silverlight. Please keep in mind that the actual run-time support also extends to AIR, Android and iOS. Future versions of WebORB will include code generators for these environments as well.

The video below demonstrates the code generator and the supported APIs. Enjoy!