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The chain of responsibility pattern is characterized by a chain of receiver objects, each object dealing

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with a certain aspect of your application.

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A slender object sends a request to an interface, and then the request is passed through the chain

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to check the different aspects of it.

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The urinal diagram shows exactly that.

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We have a handler interface which defines a contract for the concrete handlers, the concrete handlers

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will pass the request to each other up in the chain hierarchy.

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A typical usage of this would be in a logging component of an application.

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You would typically have two classes that deal with authentication and authorization, both of them

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being in the same chain generally.

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You use this pattern when you want to perform sequential tasks before reaching a final object.

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Also, when there needs to be multiple levels of escalation for different handlers, an example would

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be a payment processor where you need different types of approvals for different payments that need

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to be approved.

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Let's have a look at the implementation of this pattern in the current.