jpohhhh / envied

Handles environment variables in dart from a .env file.

ENVied

A cleaner way to handle your environment variables in Dart/Flutter.

(GREATLY inspired by Envify)

Table of Contents

• Table of Contents
• Overview
• Install
• Usage
  • Obfuscation
• License

Overview

Using a .env file such as:

KEY=VALUE

or system environment variables such as:

export VAR=test

and a dart class:

import 'package:envied/envied.dart';

part 'env.g.dart';

@Envied()
abstract class Env {
    @EnviedField(varName: 'KEY')
    static const key = _Env.key;
}

Envied will generate the part file which contains the values from your .env file using build_runner

You can then use the Env class to access your environment variable:

print(Env.key); // "VALUE"

Install

Add both envied and envied_generator as dependencies,

If you are using creating a Flutter project:

$ flutter pub add envied
$ flutter pub add --dev envied_generator
$ flutter pub add --dev build_runner

If you are using creating a Dart project:

$ dart pub add envied
$ dart pub add --dev envied_generator
$ dart pub add --dev build_runner

This installs three packages:

• build_runner, the tool to run code-generators
• envied_generator, the code generator
• envied, a package containing the annotations.

Usage

Add a .env file at the root of the project. The name of this file can be specified in your Envied class if you call it something else such as .env.dev.

KEY1=VALUE1
KEY2=VALUE2

Create a class to ingest the environment variables (lib/env/env.dart). Add the annotations for Envied on the class and EnviedField for any environment variables you want to be pulled from your .env file.

IMPORTANT! Add both .env and env.g.dart files to your .gitignore file, otherwise, you might expose your environment variables.

// lib/env/env.dart
import 'package:envied/envied.dart';

part 'env.g.dart';

@Envied(path: '.env.dev')
abstract class Env {
    @EnviedField(varName: 'KEY1')
    static const key1 = _Env.key1;
    @EnviedField()
    static const KEY2 = _Env.KEY2;
    @EnviedField(defaultValue: 'test_')
    static const key3 = _Env.key3;
}

Then run the generator:

# dart
dart run build_runner build
# flutter
flutter pub run build_runner build

You can then use the Env class to access your environment variables:

print(Env.key1); // "VALUE1"
print(Env.KEY2); // "VALUE2"

Obfuscation

Add the ofuscate flag to EnviedField

@EnviedField(obfuscate: true)

Optional Environment Variables

Enable allowOptionalFields to allow nullable types. When a default value is not provided and the type is nullable, the generator will assign the value to null instead of throwing an exception.

By default, optional fields are not enabled because it could be confusing while debugging. If a field is nullable and a default value is not provided, it will not throw an exception if it is missing an environment variable.

For example, this could be useful if you are using an analytics service for an open-source app, but you don't want to require users or contributors to provide an API key if they build the app themselves.

@Envied(allowOptionalFields: true)
abstract class Env {
    @EnviedField()
    static const String? optionalServiceApiKey = _Env.optionalServiceApiKey;
}

Optional fields can also be enabled on a per-field basis by setting

@EnviedField(optional: true)

License

MIT © Peter Cinibulk