Visual Basic

Developing Design Patterns

It might not be possible to capture a generic solution in code effectively, but it might be possible to describe an approach or some techniques that will address the problem. Patterns document design experience. They distill design knowledge and allow it to be reused. Visual Basic 6 distributed systems require that considerable thought be given to software and data architecture. You can understand the nature of some of the problems by using simulation and benchmarking, which can help you evaluate potential solutions. Design guidance can be documented. Solution frameworks can be built to encapsulate partial solutions.

Patterns for the solution and demonstration of layering, partitioning, deployment, locking, database access, error handling, application structure, and so on should be developed using Visual Basic 6. Such patterns will then form the foundation for successful future development. If a preexisting design fits the architecture of the solution, the move from requirement to implementation can happen very quickly, making it seem as if there is no design phase.

When software developers come up with seemingly unrealistic estimates for delivering systems and subsequently achieve them, they are often using preexisting designs. They judge carefully whether their client's requirement fits the architecture of their solution. They work with a limited range of applications. They move from requirement to implementation quickly, beginning with a rapid design assessment to ensure that preexisting designs fit the requirements. Design patterns and application frameworks provide architectures for building applications. Much of the thinking has been done. Provided the new application is a close fit to the pattern or framework, rapid conversion of the requirements to code can be achieved with relatively little effort spent on design.

The application must be judged to fit the design. Careful thought must go into those parts of the application that fall outside the scope of the pattern or framework. But with a close fit, the design process can be shortened.

Examples of design patterns

Consider these four uses of design patterns:

  • Front end to back end bulk data movements
  • Error handling schemes
  • Name and address deduplication
  • Executive information systems

These are examples in which design patterns have been derived and used to reduce development costs and project schedules. The first two examples are generic technical problems, and the second two are business problems. In each, a completely coded generic solution cannot be produced, but a large amount of the design work can be reused in a subsequent application. Much of this design work can be captured in templates or libraries of classes.

Visual Basic 6 provides facilities for capturing patterns through two mechanisms: a form of inheritance through the use of the Implements keyword; and templates, which provide a starting point for custom code. This starting point can capture the key design ideas without the rigidity of finished and working code.

by BrainBellupdated
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