ASP.NET Philosophy or Where does ASP.NET fit in?
The driving force behind Microsoft ASP.NET is a shift in focus from individual Web sites or devices to new constellations of computers, devicesvs and services that work together to deliver broader, richer solutions.
The platform, technology that people use is changing. Since 1992, the client/server environment has been in place, with people running the applications they need on the Win32 platform, for example. Information is supplied by the databases on the servers, and programs that are installed on the client machine determine how that information is presented and processed.
One of the things people are looking for is a one-sentence definition of “.NET”. What is it? Why should I care? ASP.NET is Microsoft’s strategy for software that empowers people any time, any place, and on any device.
Many of the goals Microsoft had in mind when designing ASP.NET reflect the limitations we previously discussed for development with previous tools and technologies.
Microsoft ASP.NET solutions
- Single Programming Model A related goal is to have development for the internet environment look very much like development for other types of software. Likewise, developing user interfaces in Windows Forms is very similar to developing them in Web Forms. There are commonly used controls, such as Labels and Text Boxes, in both, with similar sets of properties and method. The amount of commonality makes it easy to transition between the two types of development, and easier for traditional VB developers to start using Web Forms.
- Distributed Systems The Vision of Microsoft.NET is globally distributed systems, using XML as the universal glue to allow functions running on different computers across an organization or across the world to come together in a single application. In this vision, systems from servers to Wireless Palmtops, with everything in between, will share the same general platform, with versions of ASP.NET available for all of them, and with each of them able to integrate transparently with the others.
- Richer User Interface Web Forms are a giant step towards much richer web-based user interfaces. Their built-in intelligence allows rich, browser-independent screens to be developed quickly, and to be easily integrated with compiled code. Microsoft has announced an initiative for the future called the Universal Canvas which builds upon the XML standards to transform the internet from a Read only environment into a read/write platform, enabling users to interactively create, browse, edit and analyze information. The universal canvas can bring together multiple sources of information anywhere in the world to enable seamless data access and use.(The universal canvas will log on to the Ms System of servers whenever the new device is turned on) Centrally controlled OS, Office and Visual Studio.
- Easy Deployment Executable modules in ASP.NET are self-describing. Once the Common Language Runtime (CLR is explained in next sections) knows where a module resides, it can find out everything else it needs to know to run the module, such as the module’s object interface and security requirements, from the module itself. That means a module can just be copied to a new environment and immediately executed.
- Support for Multiple Languages The CLR executes binary code called MSIL (Microsoft intermediate language), and that code looks the same regardless of the original source language. All .NET –enabled languages use the same data types and the same interfacing conventions. This makes possible for all .NET language to interoperate transparently. One language can call another easily, and languages can even inherit classes written in another language and extend them current platform has anywhere near this level of language interoperability.
- Extendibility The completely object based approach of ASP.NET is designed to allow base functionality to be extended through inheritance ( unlike COM) and the platform’s functionality is appropriately partitioned to allow various parts( such as the just-in-time compilers discussed in the next section) to be replaced as new versions are needed. It is likely that, in the future, new ways of interfacing to the outside world will be added to the current trio of windows Form, Web Forms, and Web Services such as universal Canvas.
- Portability of compiled Applications .NET allows the future possibility of moving software to other hardware and operating system platforms. The ultimate goal is that compiled code produced on one implementation of .NET (such as Windows) could be moved to another implementation of .NET on a different operating system merely by copying the compiled code over and running it.
- Integrity with COM ASP.NET integrates very will with COM-based software. Any COM component can be treated as a ASP.NET component by other ASP.NET components. The .NET Framework wraps COM components and exposes an interface that ASP.NET components can work with. This is absolutely essential to the quick acceptance of .NET, because it makes ASP.NET inter-operable with a tremendous amount of older COM-based software.
Other benefits of using ASP.NET Architecture
- The Microsoft ASP.NET platform’s reliance on XML for data exchange—an open standard managed by the World Wide Web Consortium (W3C)—and modular XML Web services removes barriers to data sharing and software integration.
- The ASP.NET platform, through the ASP.NET Framework’s common language runtime, enables XML Web services to interoperate whatever their source language. Developers can build reusable XML Web services instead of monolithic applications.By making it easy to offer your XML Web services to others.
- The ability to easily find available XML Web services means you can buy pieces of your applications rather than build everything from scratch, focusing your time and money where it makes the most sense.
- Easier to build sophisticated development tools – debuggers and profilers can target the Common Language Runtime, and thus become accessible to all ASP.NET-enabled languages.
- Potentially better performance in system level code for memory management, garbage collection, and the like have yielded an architecture that should meet or exceed performance of typical COM-based applications today.
- Fewer bugs, as whole classes of bugs should be unknown in APS.NET. With the CLR handling memory management, garbage collection.
- Faster development using development tool like visual studio.net
N-tier architecture with ASP.NET
Applications developed in the ASP.NET Framework will still, in, many cases, use a DNA model to design the appropriate tiers. However, the tiers will be a lot easier to produce in ASP.NET. The presentation tier will benefit from the new interface technologies and especially Web Forms for Internet development. The middle tier will require far less COM-related headaches to develop and implement. And richer, more distributed middle tier designs will be possible by using Web Services.
Let us look into how .Net fit into n – tier architecture. When you talk about a true distributed n-tier type of application, you are talking about separating the components of the different tiers on different machines as well as in separate components. Picture shows a typical example of an n-tier application with multiple components on each machine.
There are many different ways you could configure an n-tier application. For example, the business rules may go on a separate machine and you might use .NET Remoting to talk from the client application to the business rule tier as shown in Picture.
We may also have a data input validation rule component on the client to check simple rules such as required fields and formatting. These are rules that you do not want to make a trip across the network just to check. You may then also add a business rule layer on the same tier as the data layer component to check complicated business rules that compare the data from one table to another.
These are just a few different configurations that you may utilize. Of course, you could come up with something unique that fits your specific situation. Regardless of how you structure the physical implementation of the components, make sure that the logical structure of the program is broken up into components as shown in the above ASP.Net figures.