Developing with Magic xpa Components (Magic xpa 4.x)
What are components, and why should we use them?
Components let us develop and deploy applications more rapidly than ever before. A key to assembling applications quickly is the ability to reuse existing application components to meet new application requirements.
A component is a part of a larger structure that contributes to the composition of the whole structure. The same is true of a software component, which can be defined as an identifiable application that describes and delivers a set of meaningful services using predefined interfaces.
Components are encapsulated and only reveal the services they provide in their interfaces. As a result, the actual implementation of the service within the component is hidden from the outside world.
A component can be an entire business-logic module, such as an accounting module, and a component can also be much smaller in scope, such as an object that checks the validity of an identification number.
When using components, it is important to focus on what a component does and not changes to the component from the applications that use it.
Every application developer has the same goal -- to produce the most effective applications in the least possible time. And every developer knows that exploiting the services available in the development environment is essential for achieving that goal. This is where components play a big part.
The heart of component-based development is the knowledge that business services designed as components are inherently reusable, and easily upgraded and deployed.
A component can be modified and upgraded without the host project because it exists as an independent entity. This makes upgrading, customizing, and maintaining applications a lot easier. For example, if a programming glitch or quirk is found, you only need to fix the faulty component and not the entire project. Only this one component needs to be sent to your customers. Your projects no longer become outdated and unable to take advantage of changing situations or new technologies.
Deploying with components makes your application easy to configure. Suppose a customer purchases a component-based package from you and initially decides to purchase only one module. If the customer wants to buy another module in the future, all you have to deploy is the new component. For example, a customer who buys an accounting package with a bookkeeping module and a tax module can decide at any later stage to also purchase a stock-tracking module.
As your component library grows, your ability to customize new applications increases along with it. For example, if at one time the stock-tracking module was only part of the accounting application, it may now also become part of an e-commerce application, significantly reducing the e-commerce application's development time.
In short, developing with components not only means that time-to-market requirements are easily met, but also that you can rapidly respond to changes and meet today's dynamic business requirements.
This concept paper covers the following subjects:
Magic xpa Components
Creating and Loading Components
Effective Application Components
Component Runtime Behavior
Events and Handlers
Nested Magic xpa Components
Recursive Magic xpa Components
