Subject: Advanced Internet Technology

Topic: RIA and Mashup

Difficulty: Low

Characteristics of RIA

1. Direct interaction: An RIA can use a wider range of controls that allow greater efficiency and enhance the user experience. In RIAs, for example, users can interact directly with page elements through editing or drag-and-drop tools. They can also do things like pan across a map or other image.

2. Partial-page updating: RIAs incorporate additional technologies, such as real-time streaming, high-performance client-side virtual machines, and local caching mechanisms that reduce latency (wait times) and increase responsiveness.

3. Better feedback: Because of their ability to change parts of pages without reloading, RIAs can provide the user with fast and accurate feedback, real-time confirmation of actions and choices, and informative and detailed error messages.

4. Consistency of look and feel: With RIA tools, the user interface and experience with different browsers and operating systems can be more carefully controlled and made consistent.

5. Offline use: When connectivity is unavailable, it might still be possible to use an RIA if the app is designed to retain its state locally on the client machine.

6. Performance impact: Depending on the application and network characteristics, RIAs can often perform better than traditional apps. In particular, applications that avoid round trips to the server by processing locally on the client are likely to be noticeably faster. Offloading such processing to the client machines can also improve server performance. The downside is that small, embedded and mobile devices which are increasingly common may not have the resources necessary to use such apps.

Web Services

• A web service is a software system designed to support interoperable machine-to-machine interaction over a network. It has an interface described in a machine-processable format (specifically WSDL).

• Other systems interact with the web service in a manner prescribed by its description using SOAP-messages, typically conveyed using HTTP with an XML serialization in conjunction with other web-related standards.

• Web services may use SOAP over HTTP protocol, allowing less costly (more efficient) interactions over the Internet than via proprietary solutions like EDI/B2B. Besides SOAP over HTTP, web services can also be implemented on other reliable transport mechanisms like FTP.

• The Web Services Architecture Working Group defined a web services architecture, requiring a standardized implementation of a "web service."