Please pay attention to the technologies that transcend vital HTML standards in the past two years, people's interest has always wanted to build a "rich client": this is a user interface, it is more robust than the interface that can be implemented with HTML. The reaction is more sensitive and more interested in visualization characteristics. RIA (RICH Internet Application, Rich Internet Application) technology allows us to deploy a client program as a simple way as a web like WEB is as simple as in the Internet. Regardless of whether the HTML application system can be fully replaced in the future, the HTML application is used to run a complex application system with fat client technology, RIA does provide an inexpensive choice. In this column, I will list some current RIA products and technologies and provide some inspirations to start applying these products and technologies. On the DEVTRENDS site and the upcoming near-average Oracle Magazine magazine, I will explore specific technologies and strategies to deploy RIA using Oracle platforms. Why use RIA? HTML-based applications become popular because the deployment cost of the application system is low, the structure is simple, and HTML is easy to learn and use. Many users and developers are willing to abandon user interface improvements from desktop computers to achieve quick access to new data and application systems. The benefits of Web-based approach are much larger than those who lost some important UI. However, some application systems are not fully suitable for HTML technology. Complex applications may require multiple extraction of web pages to complete a transaction. In some areas, such as medical and financial areas, this often leads to low speeds of interaction. Let me consider a project management system: We can implement it as an HTML application, but if the user can see and operate chart, schedule, and various hierarchical structures, it will obviously work better. In addition, although HTML begins to go, even simple interaction activities still need to be done with a lot of scripts. Even if an input form is carefully arranged and a comprehensive script design, it is only a simple "name / value" pair from the browser. If an HTML form can send and receive more complex data structures in the form of an XML document, it is much better. RIA utilizes relatively robust client description engine, which provides content dense, response speeds and user interfaces. In addition to providing an interface with a variety of controls (slides, date pickers, windows, tabs, fine-tuning controllers, etc.), RIA generally allows SVG (Scalable Vector Graphics, Scalable Vector Diagram) or other Techniques are always constructed to build graphics. Some RIA technologies can even provide full-activity animations to respond to data changes. Another advantage of RIA is that the data can be cached on the client, so that a user interface that is more faster than the HTML-based response speed and data to and from the server. For wireless devices and equipment that require occasional connections, the future trend is definitely developed to the direction of the client and will gradually stay away from the text-based web client. The application system running on the laptop can be designed to work in an offline manner or at least when the connection is lost. Figure 1 shows a typical RIA architecture. XML is usually used as a format of data transmission, and sometimes it is also used to describe the layout of the form. In many instances, the client can maintain a connection to the data source so that the server can update the client data in real time. Access to an Oracle data can be done through a web service call.
Techniques for Fulk-envoys are some of the available RIA technologies: Java: Some fairly complex client applications (Oracle's JDevelopS) are written in Java, this shows that you can use Java to build almost anything can be imagined Get rich client applications. So far, Java has appeared for a few years, and fully supports creating a form-based user interface. In addition to user interface components in Java Basics (JFC / SWING), developers can also develop from the SWT toolbox from Eclipse Project and many third-party toolboxes. For graphics, Java 2D API can be used for a very complete and very complex graphics API. Java also has unbeatable support for XML and Web services. You can deploy applications with Java plug-in software through a web browser or using the New Java Web Start technology in the Java runtime environment. The main drawback of the establishment of a client program using Java is its complexity (even if simple forms and graphics are required to write very cumbersome code). It has the advantage that Java's comprehensive support for Web standards, and the profound connotation of the language and class library. XUL: XUL (Mind "Zool") is an XML-based user interface language that comes from the Open source project of Mozilla. It can be used to establish a form application that can not only be run on the Mozilla browser, but also on other description engines, such as Zulu (a Flash MX component) and Thinleys (a Java implementation). The XUL description engine is very small (100K or less), which can also generate XML data using XML data. Like Java, XUL also has a very large user group that has a large number of open source tools, such as theodore ThinletEtEditor (see "Next") - a way to lay out the user interface in a graphical manner, and can Generate the corresponding XUL Java application. One of the main disadvantages of XUL lies in that it has not yet obtained support for a major commercial entity. The biggest advantage of XUL is that it is integrated with the Gecko engine (opened the gate to a large number of web standards), and it is a very expressive and concise language compared to most other XML user interface description languages. Macromedia Flash and Flex: Flash are a mature commercial product that can introduce an interactive graphical interface in a web page. After upgrading, the new version contains the function of establishing a form of application. Although Flash is also controversial as a front-end technology that is the most widely deployed on the web (depending on the Flash Player version selected), it is said that there is already more than 98% of desktop systems to support Falsh. Since the Flash tool used to create an animated graphic is very powerful and visualized (the opposite other technical requirements are low graphic code), the graphics designer uses it very heartbeas. The scripting language used by Flah is a variant of ActionScript - ECMAScript 1.5, which is called JavaScript. The Flex product adds an XML description language for Flash so that the user interface can be compiled and can be described with Flash Player. Flex allows traditional development organizations to better understand and use Flash. The biggest disadvantage of Flex and Flash is that the support of the XML and Web services is limited, and the environment as an application development tool is not much mature.
