Activity 16-2: Adapter, Bridge and Proxy Patterns

Proxy

Video segment from: Pile’o’patterns

• 44:00-46:50 The proxy pattern: Basic example
• 46:50-52:50 The proxy pattern and the database

Proxy pattern allows two objects to communicate along a communications boundary, without knowing that the boundary exists.

Adapter

Video segment from: Pattern apocalypse

The adapter pattern allows us to connect a client to a service without the two knowing about each other.

• 66:20-73:00 The button-light problem
• 73:00-75:00 The adapter pattern (object form)
• 75:00-78:00 The adapter pattern (class form)

Bridge

Video segment from: Pattern apocalypse

Bridge pattern is useful when a set of objects can be expressed via multiple inheritance hierarchies.

Example: Employees have different payment schedules and different payment classifications.

The Bridge pattern is essentially a “bunch of strategies”.

• 10:10-13:40 Motivation for the Bridge pattern: The m times n problem
• 13:40-23:30 The Bridge pattern

As time permits:

• 24:00-26:40 Motivation for chain of responsibility pattern
• 26:40-35:00 Chain of responsibility pattern