Implementing Domain-Driven Design

Render Data Transfer Object from Aggregate Instances

A popular way to tackle the problem of rendering multiple Aggregate instances to a single view is to use Data Transfer Objects [Fowler, P of EAA], or DTOs. The DTO is designed to hold the entire number of attributes that need to be displayed in a view. The Application Service (see “Application Services”) will use Repositories (12) to read the necessary Aggregate instances and then delegate to a DTO Assembler [Fowler, P of EAA] to map the attributes of the DTO. The DTO thus carries the full complement of information that needs to be rendered. The user interface component accesses each individual DTO attribute and renders it onto the view.

With this approach both reads and writes are performed ...