Decorator Pattern, also called Decorator Pattern, is a design pattern in the field of object-oriented programming that dynamically adds new behaviors to a class. In terms of functionality, the modification pattern is more flexible than subclassing, allowing you to add some functionality to an object rather than to the entire class.
For example, there is a technical forum where users communicate through messages. Since the forum is full of acquaintances at the beginning, there is almost no need to review the content of the messages. The page for receiving messages can look like this:
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Later, as the forum became famous, some people posted links on it, and it was necessary to filter messages containing links. The forum further developed and found that in addition to developing In addition to spam links, there are also a lot of useless spamming, and later there may be attacks and other abnormal posts. Therefore, for the management of forum posts, a separate class can be abstracted for management. When the filtering rules need to be expanded, Can be dynamically expanded.
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In python, there are no abstract classes and methods, and the implementation is simpler:
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In Javascript , there is no strict class, all inheritance is based on prototype, it will take a little effort to understand:
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Since Javascript lacks the characteristics of classes, inheritance is a bit difficult for it. It's useless. The above code looks more like the processing of two functions. In python, there is a simpler way to add decorators. You can directly add decorators to functions directly through "@" to achieve the purpose of extending functions. For example:
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The purpose of the decoration mode is to solve the problem of dynamic expansion of functions. The essence of the decoration mode is the flexible processing of objects. Understanding the decoration mode can not only provide an in-depth understanding of the oriented Object programming can improve programming thinking skills.
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