Implementing Domain-Driven Design

Decoupled Service Output

A couple of times earlier I discussed the use of Data Transformers as a way to accommodate disparate client types with the specific data type they require. That approach uses Transformers to produce the data in a specific type that implements an abstract interface that all related types share. Again, from the client’s perspective it might look like this:

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TenantData tenantData =     tenantIdentityService.provisionTenant(             ..., myTenantDataTransformer); TenantPresentationModel tenantPresentationModel =     new TenantPresentationModel(tenantData.value());

The Application Services are designed as an API, with input and output. The reason for passing in a Data Transformer is to produce ...