How to NOT use Dagger 2 when you have Redux

People often remember Redux for its state management. But surprisingly overlooked by many, it also uses injection to map its states to a view. The following is an example about how a React.js TodoList view receives a to-do list.

So a question raises, what if, alongside states (a.k.a. global variables) injection, the dependencies are also injected in the Redux way. Isn’t it a much neater way than to construct an elaborative dependency annotation, using @Provider, @Inject, @Modules, @Components, etc, etc as in Dagger 2.

2. The REST Api dependency.

Two simple weather APIs are integrated to first fetch a city’s woeid , then use the woeid for the city’s current temperature. They can be found in WeatherApi.swift and WeatherApi.kt

3. The Redux Store, State, Reducer and Action

As a simple demo, the WeatherRedux.kt and WeatherRedux.swift contain the actions, a reducer, app states and a store

4. The SideEffect class

Based on Redux, a side effect performs an asynchronized operation to fetch some data, then call store.dispatch to save the data into store.

The side effect uses WeatherApi to perform the async calls.

5. Injection to a view

The newState will be called both on view start and on a state change in the store. Here, the WeatherApi dependency is injected into the SideEffect.

6. Hola!🎉

That’s all you need to add a DI into your code

We spent all the time above to discuss how to implement DI in a mobile app. But why we need the DI in the first place? 😅

The most important reason for DI is to make each component of an app readily available for independent unit testing. DI can decouple a component away from its dependencies. Then in the test time, mocked dependencies can be injected instead, in our case, a FakeWeatherApi in the place of a real WeatherApi.

2. Execute a unit test

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