Air RIA and flex!

This morning, I turned on my computer and studied the cs4 trial version released on the Adobe homepage. I suddenly found something called air. When talking to friends in the group, some people say it's not Nike's shoes, OMG!
Let's introduce it below!
What is Adobe AIR?
Adobe Integrated Runtime (air) is a platform that runs across operating systems. It uses existing web development technologies (flash, flex, HTML, JavaScript, Ajax) to build internet-rich applications. Program And deploy it as a desktop application.
Air supports existing web technologies such as flash, flex, HTML, JavaScript, and Ajax. You can use your most skilled technologies to develop the most user-experienced Ria programs you have ever seen, for example, an air program can be built using one or more of the following combination technologies:
Flash/flex/ActionScript
Html/JavaScript/CSS/ajax
PDF can be embedded in any application
As a result, the air application can be:
Based on flash or flex: The application root content (understood as a container) is flash/flex (SWF)
HTML or PDF Based on flash or flex. The root content of the application is HTML based on Flash/flex (SWF ).
(HTML, JS, CSS) or PDF
Based on HTML, the root content of the application is HTML, JS, and CSS.
HTML-based Flash/flex or PDF. The root content of the application is HTML-based Flash/flex (SWF) or PDF.
Users use the air application in the same way as traditional desktop programs. After the runtime environment is installed, the air program can run the same way as other desktop programs.

Because air is the application running environment, it is very small and invisible to users. The runtime environment provides a consistent set of cross-operating system platforms and frameworks to develop and deploy applications. Therefore, your programs do not have to be tested on each platform, if it is developed on one platform, it can be run on other platforms, which has many advantages:
The development of the air application requires no additional cross-platform work, saving time, because the cross-platform work is done for us (as long as other platforms support air ).
Compared with the web technology and its design model, the air application is developing rapidly. She allows the web development technology to be moved to the desktop without having to learn the desktop development technology or the complex underlying layer. Code This is easier to learn than low-level languages such as C and C ++, and does not need to process the complex underlying APIs of each operating system.
What is Ria?
1. What is Ria?
Rich Internet application (RIA) it is a new generation of network applications that integrate the best user interface functions of desktop applications with the universal adoption of Web applications, fast, low-cost deployment, and real-time interactive multimedia communication. Rich Client in RIA provides a runtime environment that can host compiled client applications (in the form of files, transmitted over HTTP, client applications use an asynchronous client/server architecture to connect to existing backend application servers. This is a secure, scalable, and adaptive new service-oriented model, this model is driven by the web service used. The comprehensive communication technology combining sound, video, and real-time conversation gives Ria an unprecedented online user experience.
Is the application model of RIA:

2. Background of RIA
Enterprise-level applications have undergone several important changes in system architecture. In this process, the client performance has been improved. Figure 1 shows the development process of rich Internet application:

· Host-based applications: applications provide text-based non-graphical user interfaces, which can only be accessed by internal personnel.
· Client/Server (C/S) Applications: in 1990s, with the appearance of windows and the enhancement of client processing capabilities, client/server applications emerged, they use graphical user interfaces, and the client's data processing capabilities are relatively strong. However, client applications need to be constantly updated, so deployment costs are relatively high and can only be used by a few people.
· Browser/Server (B/S) Applications: In the middle of 1990s, the Internet developed rapidly and browser/server applications emerged, the wide use of web solves the difficulties of C/S Application Deployment and updating. However, because the user interface in the form of HTML pages is used, the client's data processing capability is lower than that of the C/S application.
The disadvantages of the C/S architecture are deployment and update. The main disadvantage of the B/S architecture is that it is restricted by the restrictions of HTML and cannot use rich effects to display data like C/s. The user experience is poor. In addition, stable client/server connections are also necessary, and network interruptions will make the B/S program unable to run. From c/s to B/S, the two are limited by the technology itself, respectively, developed into the mode of heavy client and heavy server, the emergence of RIA brings us a chance to strike a better balance between the client and the server.
3. Advantages of RIA
Ria provides interactive user interfaces for message confirmation and format orchestration, and provides quick interface response time for refreshing pages; provides common user interface features such as drag-and-drop and online and offline operations. The characteristics of RIA Web applications include: immediate deployment, cross-platform, gradual download to retrieve content and data, and full use of widely accepted Internet standards. The communication feature of RIA includes real-time interaction sound and images.
The role of a client in RIA is not only to display pages, but also to calculate, transmit and retrieve data asynchronously with user requests behind the scenes, display integrated user interfaces, and use sounds and images comprehensively, all of this can be done without relying on the server or backend connected by the client.
For enterprises, the advantage of deploying RIA is:
1) RIA can continue to use existing application models (including J2EE and. Net), so there is no need to replace existing Web applications on a large scale. With rich client technology, you can easily build applications that are more intuitive, easy to use, responsive, and available offline.
2) RIA can help enterprises provide diversified and important business benefits, this includes increasing product sales, increasing brand loyalty, extending website stay time, frequent repeated access, reducing bandwidth costs, reducing support for help, and enhancing customer relationships.
4. Current Development Trend of RIA
In the past two to three years, Web developers have been trying to build a client richer than traditional HTML: This is a user interface, it is more robust, responsive, and visually interesting than HTML interfaces. The emergence of RIA technology allows us to deploy rich client programs on the Internet in a simple way like using web. Whether or not Ria can completely replace the HTML Application System as people have guessed in the future, for organizations that use the fat client Technology in the C/S architecture to run complex application systems and deploy web application systems with the thin client Technology Based on the B/S architecture, RIA does provide a cheap option. The following describes several powerful or characteristic Ria client development technologies:
1) Adobe Flash/flex/air
From 6.0, flash gradually has the function of creating a form-style application. According to Macromedia, Macromedia Flash Player is installed on more than 98% of desktop browsers. This allows the RIA client using Macromedia Flash Player to support a wide range of platforms and devices.
Flex is a representation server and application framework launched to meet the needs of enterprise-level programmers who want to develop Ria. It can run on J2EE and. Net platforms. Flex indicates that the server provides standard and declarative programming methods and processes, and provides runtime services for the development and deployment of presentation layers that enrich client applications. Flex developers use XML-based mxml to define rich user interfaces. The language is translated by the flex server into a client application in swf format and runs in Flash Player.
2) Laszlo
Laszlo is an open-source RIA development environment. When using the Laszlo platform, developers only need to write the Description Language LZX (which integrates XML and JavaScript ), the Laszlo platform running on the J2EE application server will compile the file into swf format and transmit it to the client for display. From this point, Laszlo is essentially the same as flex. Flash is a display format supported by any browser, which solves the problem of porting between browsers. In addition, in future plans, Laszlo can also compile LZX into Java or. NET local code, greatly improving the running efficiency.
3) aveon
Microsoft's avron is part of the next version of Windows (codenamed "Longhorn"). It is a graphics and Display Engine, mainly composed of a set of classes newly added to the. NET Framework. Avron defines a new markup language used in Longhorn, codenamed "XAML" (eXtensible Application Markup Language ). You can use XAML to define the layout of text, images, and controls. program code can be directly embedded into XAML or stored in a separate file. This is very similar to mxml In Flex or LZX In Laszlo. The difference is that aveon-based applications must run in the Longhorn environment, while flex and Laszlo do not depend on the platform. They only need a browser with a flash player.
4) Java SWT
Java has been around for several years and supports creating a form-based user interface. In addition to the user interface components in the Java basic class (jfc/swing), developers can also use the SWT toolbox from the Eclipse project and many third-party toolboxes for development. For graphics, Java 2D API can be used: a very complete and complex graphic API. You can use a web browser to use Java Plug-in software, or use a newer Java Web Start Technology in the Java Runtime Environment to deploy applications. The main drawback of using Java to build rich client is its complexity (even for simple forms and graphics that require very cumbersome Code) and the low market share of Java browser plug-ins.
5) XUL
XUL is an XML-based user interface language that comes from Mozilla's open source code project. It can be used to create a form application. These applications can run not only 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 (less than KB). It can use XML data or generate XML data. A major drawback of XUL is that it has not yet been supported by a major commercial entity. The biggest advantage of XUL is its integration with the gecko engine (opening the door to a large number of web standards ), compared with most other XML user interface description languages, it is a very expressive and concise language.
6) bindows
Bindow is a web form framework developed using JavaScript and DHTML. Javascript is used to display and process the client interface, and XMLHTTP is used to transmit information between the client and the server. The expressiveness of JavaScript on the client is unquestionable. Using javascript can almost achieve most of what Windows applications can do. XMLHTTP has always been used to implement "no refreshing" Web pages, it works with JavaScript to transmit data from the server and client. One of the main disadvantages of bindows is that it uses the method of loading all at a time to implement the script library. During the loading period of the window, a long wait process is required, even the browser process will produce no response. This bindows does not follow the "how much to use" principle. In addition, IE6 technology is widely used internally, and non-ie browsers are not taken into account, which limits the popularity of bindows.
5. Future Development Forecast of RIA
As for the current usage of RIA, there is still a long way to go from the "RIA era. Traditional web applications and Ria will coexist in the next few years. The author believes that only Flash/flex applications based on Flash Player and Microsoft avron-based applications are the ones that really have the power to popularize a wide range of client applications. In the short term (estimated 2-3 years), Flash/flex applications may be dominant in the emerging network application market. Over time, the market share of Flash/flex applications may be slowly eroded by aveon-based applications. Of course, new versions of Flash Player and flex will also be released in the future. Compared with upgrading the operating system or installing the aveon operating environment, people are certainly more willing to upgrade Flash Player. Flash/flex applications also have their inherent weaknesses. The execution efficiency and local resource operation restrictions of Flash Player cannot be compared with that of aveon. Compared with plug-ins in browsers, aveon applications have a wider range of operational space and higher execution efficiency.
Microsoft is still promoting a client program technology called smart client. Microsoft says Smart Client is a better client than rich client, therefore, applications using the Smart Client are not counted as Ria. Currently, I cannot answer this question. The reason why we mention Smart Client is that the features of Smart Client have many similarities with the rich client. Smart Client has features such as automatic update, offline data processing, and the ability to use local resources. The availability of local resources is undoubtedly a major selling point, because the Flash/flex application in the browser cannot operate some local resources at present, for example, the Flash/flex application cannot save online files locally or modify local files. Although Macromedia central1.5 can perform simple operations on local files and the RIA developed by flex1.5 can also run on Central, it is still a problem to make Central widely available. Compared with the lightweight rich client, the Smart Client is closer to the client program in the C/S architecture. The positioning of rich client is different from that of Smart Client: rich client is more suitable for lightweight browser-based network application clients, and smart client is more suitable for Windows desktop applications.
What is Flex?
Flex is the Presentation Server (Presentation Service) released by Macromedia. It is a Java Web iner or. for an application of Net Server, the. mxmlfile (pure XML file and the actionscriptfile file correspond to the. SWF file, which is sent to the client and interpreted and executed by the flash player or Shockwave Player of the client, giving users a rich user experience.

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