Rich Internet Applications The Next Stage of Application Development

1. Rich Internet ApplicationsThe Next Stage of Application Development Jason Farrell, George S. Nezlek Grand Valley State University Conf. on Information Technology Interfaces 2007 章詔博

2. Outline • Abstract • Introduction • RIA • Limitations of RIA development • RIA development environments • Conclusion

3. Abstract • Early Internet applications were written using a classic client/server model, with multiple content pages refreshed for each user action. • Ajax are being used to promote this new style of Internet programming.

4. Abstract • Rich Internet Applications (RIA) offer greatly enhanced usability, and allow Internet programs to rival their desktop counterparts for functionality.

5. Introduction • Usability has become a central concern for software development in general. • Web-based business environments are clearly in transition to more experience-oriented models.

6. Introduction • Web businesses do not suffer from these limitations - the nearest competitor is always a click away.

7. Introduction • Rich Internet Applications (RIAs) utilize asynchronous techniques such as Ajax (Asynchronous JavaScript and Xml) to enable real time data communication and dynamic rendering, which give the web interface a more desktop-like application feel.

8. RIA • By their very definition, RIA will often rely on emerging, asynchronous, and possibly non-client-server technologies. • And/or a reliance on a plug-in being present to allow an application to execute.

9. RIA • RIA can be organized into three distinct types as a function of how they are developed or deployed. 1.plug-in-based 2.script-based 3.browser-based

10. RIA • 1.plug-in based: 1. creating the application on a dedicated platform (or in a dedicated environment). 2. deploying it as either an embedded solution or standalone application launched from the browser.

11. RIA • An example of the embedded approach is Adobe’s Flex 2 technology, which uses an XML based markup language called MXML to declaratively create Flash based applications. • By doing this from the browser, developers can ensure that the specified version is always available.

12. RIA • 2.script-based: These applications employ a combination of technologies to achieve their results, typically including XHTML/HTML, CSS, DOM, and JavaScript.

13. RIA • The idea is to use CSS and HTML to style and present the interface, use JavaScript to make an asynchronous request to the server, and finally use DOM Scripting to perform 'on-the-fly‘ rendering.

14. RIA • This strategy gives the application a minimal footprint and requires no software to be pre-installed. • However, some of the technologies have well-documented compatibility problems, based on platform and browser environments.

15. RIA • Because of these incompatibilities, developers must exercise caution in order to prevent instances of “dead” features.

16. RIA • An application is first developed using the traditional model for a normal Internet application. JavaScript is then used to check for its own existence and modify page components as necessary.

17. RIA • 3.browser-based These generally incorporate a user interface language, built on XML, which allows developers to specify the needed elements and their interactions in a declarative format.

18. RIA • The key benefit of this approach is the basis on existing XML standards supported by the W3C such as CSS 1 and 2, DOM Levels 1 and 2, and JavaScript 1.5+. • XUL is designed to be platform independent, thus allowing for portability between platforms.

19. RIA • The common element of RIA technologies is the ability to leverage the rendering and communication powers of the underlying scripting engine to request the data they need, and update the user interface to display it.

20. RIA • The asynchronous nature of RIAs can also be used to update users on the status of long running processes.

21. RIA • Because applications only send pertinent data to the server, and only receive lower volumes of information that is changed, the volume of network traffic being generated is greatly reduced.

22. RIA • The application still communicates with the server, but fractional rather than full pages are transmitted.

23. RIA • This approach permits smaller incremental updates to reflect user actions, making the resulting client very thin and permitting single page interface for applications, rather than the traditional multi-page interface common to older Internet applications.

24. RIA

25. RIA • A combination of anonymous and named functions are registered to events to send data, and handle return requests. • When a return request is received (in either plaintext or XML format) JavaScript is used to manipulate the Document Object Model (DOM), updating the user interface to reflect the result of the action.

26. RIA • When creating RIA, one of the primary goals is to keep data synchronized, and allow the user interface to update in response to user actions.

27. RIA • One of the main reasons for using RIA is to create a user impression that tasks are being done the instant a user request is initiated. • RIA should support undo and redo operations.

28. Limitations of RIA development • 1. Accessibility • 2.Lack of a coherent architectural style for these applications and libraries. • 3. RIAs and asynchronous Internet applications is fairly new.

29. Limitations of RIA development • Among these many styles, the REpresentationalState Transfer (REST) style is considered the most powerful and useful.

30. Conclusion • The trend is toward providing a richer set of functionality, to close the gap of interactivity and usability between Internet applications and their desktop counterparts.

31. Conclusions • The goal of these Rich Internet Applications is to function like their desktop counterparts, and to be intuitively familiar to end users who spend the majority of their time interacting with desktop applications.