Dependency injection

Managing dependency properly helps us keep our code clean and make it easier to maintain and make changes.

What is dependency injection?

Dependency injection is a technique in which an object can receive other objects that it depends on.

What is GetIt?

GetIt is a simple service locator for Dart and Flutter projects.

• It allows to register dependencies and later retrieve them across the app.
• It also allows to register factories, singletons, lazy singletons, and static dependencies.

Installing GetIt

To install GetIt, we need to add the following dependency to our pubspec.yaml file:

dependencies:
  get_it: ^7.6.6

We can also do the same from the terminal.

flutter pub add get_it

Finally, run the following command to install the dependency:

flutter pub get

Registering dependencies

To register dependencies

• Create a new file called dependencies.dart in the lib folder.

import 'package:get_it/get_it.dart';
import 'appwrite/appwrite.dart';


void initDependencies() {
    GetIt getIt = GetIt.instance;
    getIt.registerLazySingleton(() => Appwrite());
}

We need to call the initDependencies function from the main.dart file.

import 'package:flappwrite_tracker/dependencies.dart';
import 'package:flutter/material.dart';

void main() {
  initDependencies();
  runApp(MainApp());
}

Once we have registered the dependencies, we can use them anywhere in our app. We will do that in the up coming lessons.