they place a 2nd order before their first order has shipped and if that happens, we would like to merge orders together. Some customers might place more than one order. (Note: In sample code, these classes are renamed to OrderOld and OrderItemOld due to later updates.) New Requirement (Merging Order) DesignĬore components of a composite pattern are:įollowing is the UML diagram of composite pattern: Once data is built this way, we can treat individual objects the same as a composite object. This is done by configuring your objects into tree structures. The basic concept is that components represents part or whole structure. In this post, we will learn some basic theory coving concepts, design, use cases and we will also see implementations of this pattern. Lets start by stating that composite is not composition (composition is another useful software design approach. This make things easier for clients due to uniform way to work with individual items and for collections. It helps deal with tree structure of information. The composite design pattern generalize a hierarchical structure.
