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are well developed will the two come together for integrationwhich shouldn't take much time, depending on the complexity of the behavior being carried out. If one finishes before the other, the slower developer (for lack of a better term) could check out the category with which to work. |
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Advanced Design Issues: Design Patterns |
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Although the identification of patterns isn't a new science, the concept of design patterns has been gaining rapid popularity in the object-oriented software development community over the past several years. The purpose of design patterns within the OO community is to make available a repository of problems and solutions to help software deal with common redundant issues. Identifying design patterns facilitates communication of indepth knowledge and experience about these recurring problems and deciding how best to implement solutions. Having this at the disposal of developers, especially Visual Basic developers, results in well-structured system architectures that provide rapid reuse for the client and are understandable to fellow developers. |
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The idea of object-oriented design patterns is a very complex one, suitable for intermediate to advanced object technologists. The premier book on design patterns is Design Patterns: Elements of Reusable Object-Oriented Software by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides. Several others exist. It's advisable to acquire such books to familiarize yourself with the idea of design patterns. However, be forewarned that current design patterns books are written with C++ in mind because many design patterns deal with inheritance, an area in which Visual Basic isn't yet capable. |
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Christopher Alexander, a noted scientist and building architect/theorist, describes a pattern as a three-part rule, which expresses a relation between a certain context, a problem, and a solution. The pattern is, in short, at the same time a thing, which happens in the world, and the rule that tells us how to create that thing, and when we must create it. It is both a process and a thing; both a description of a thing that is alive, and a description of the process that will generate that thing. Because the term design pattern has become immensely popular, to the point of being a buzzword, some vanity patterns have entered the community that are not quite solutions. |
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Interested in writing a design pattern? Doug Lea, a pattern author at http://st-www.cs.uiuc.edu/users/patterns/patterns.html, wrote a checklist for documenting patterns. The following list paraphrases what Lea suggests a pattern should reflect: |
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A specific kind of problem |
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The context in which a given problem occurs |
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