A Study And Design On OpenLaszlo-Based Data-Driven Application

With the development of web application, user experience, which has already been one of the major metrics for software quality, becomes more and more important in design and development of web application. OpenLaszlo, an excellent member of Rich Internet Application technologies, is one of the best in improving user experience and increase the usability of web applications. However, considering OpenLaszlo is still an emerging technology, it has some difficulties in designing a typical data-driven application. Thus, most OpenLaszlo-based applications are in the phase of proof of concept instead of mature and large-scale usage. Furthermore, certain flaws exist in current methods and technologies for the interaction between OpenLaszlo and other mature background technologies. It is a worthy research to discuss design principles how to develop high-usability data-driven application from front-end to back-end.This paper analyzes the major steps in developing an OpenLaszlo-based data-driven application.First, this paper focuses on the performance issues on OpenLaszlo client itself. It uses a case to illustrate the common bottlenecks of OpenLaszlo applications in real life. After that, the paper puts forward a set of solutions to resolve these issues.Besides, this paper proposed an interaction method based on a lightweight component, which is different from other traditional methods. Instead of depending on the heavy-weight OpenLaszlo server, It is based on HTTP protocol to transfer the data. After that, the method uses the XML parser and encapsulation on the server side to passes the action name and data from OpenLaszlo to back-end. Similarly, the process of this method is also reversible. In addition, based on this method, this paper also designs a matching policy for the client request, making it possible for the server to call the correct method even if the information from client side is inadequate. This paper first proposed two static matching strategies, and a dynamic one combining the advantages of these two static ones.Finally, this paper conducts several experiments to prove the correctness of methodologies proposed. Experiments on responding time and loading time are conducted to compare the performance of OpenLaszlo application after the principles are applied. Related performance experiments are also done in lightweight component technology and others, which proves that the former has an advantage over the latter. Accuracy experiments about matching strategies are also mentioned in this paper.All in all, the methods in this paper have simplicity, flexibility and scalability. Meanwhile, the interaction method between back-end which fully utilizes the mature HTTP protocol increases the efficiency to some extend.