README.md

QLoop-Demo

Demonstration using QLoop for the implementation and testing of an iOS view controller using declarative composition.

Includes real-world examples of:

• observer pattern and reactive rendering
• declarative chaining of asynchronous operations
• basic dependency injection (binding) using InterfaceBuilder
• utilizing background threads
• handling errors
• unit-testing solutions

Getting Started

This application has a dependency on qloop, which has been imported as a git submodule. Whenever you clone or update from the source repository, don't forget to also update the submodule using:

git submodule update --init

Of particular interest

• The view controller in this example is using an observer pattern. Here, we've placed an empty loop in the view and added just the code that renders/updates the view whenever input is received through either the onChange(_:) and/or onError(_:) events.

• You are not limited to using only one loop in this manner. An entity can have as many loops as it needs for a variety of purposes.

• You should not attempt to create subclasses of loops, segments, or anchors. Instead, you should try and implement your operations generically, independent of each other. Then have your injector, delegate, factory, or whatever attach the operations to segments when they're needed.

• At the start of our tests, after loading the view from the storyboard, we call destroy() in order to return the loop to its natural, empty state.

• The separation of the loop from its path allows us to safely invoke its input and output however we wish. We can use synchronous unit testing techniques to verify our code's reactions.

Should you encounter any bugs or think it needs a particular feature, feel free to open an issue.