VDT: A data integration model for web applications

This paper proposes a three-layer model for web applications named VDT (View, Data Processor and Transceiver) and analyzes its performance. It standardizes the design of a web application when fetching data from different sources on both a browser by AJAX (Asynchronous JavaScript and XML) and an agent server. It has the benefits of general hierarchical models such as loosely coupled structure which can fit the varied data sources. Using the VDT model, we implement two web maps applications integrating data obtained from three sources. One gets the data from original sources directly by AJAX API while the other does through an agent server. They are vertical search engines of course. We compare these two applications and conclude that each has its own advantages in the response time, resource consumption and quality of results.