Services

At a Glance

• Provide access to shared resources e.g.
  • in-app messages system,
  • persistence storage
  • realtime data services
  • anything that interacts with a Web API
• Represent a contract - some would call these interfaces!

More Details

Services provide access to shared resources such as an in-app messages system, persistence storage, realtime data services or anything that interacts with a Web API.

Services represent a contract; they expose functions with defined parameters and return values. Yes, some would call these interfaces!

In large scale applications services are essential. They:

• Allow implementations to be swapped in and out in different environments/scenarios or if a better implementation comes along
• Facilitate testing of features, avoiding IO
• Result in a loosely coupled application architecture
• Enable development to take place when the real implementation isn't ready yet

We've found that they also:

• Enable new types of development tools and workflows
• In conjunction with MVVM they allow Features to be tested End-to-End (UI <-> Service)

Workbenches in particular are a good example of this where you can easily add code to enable development or even build your own helper tools.