Welcome to Envy, code generator for extracting environment variables.

Installation

To use Envy, you will need your typical build_runner/code-generator setup.
First, install build_runner and Envy by adding them to your pubspec.yaml file:

If you are using in a Flutter project:

$ flutter pub add envy_annotation
$ flutter pub add --dev build_runner
$ flutter pub add --dev envy_generator

If you are using in a Dart project:

$ dart pub add envy_annotation
$ dart pub add --dev build_runner
$ dart pub add --dev envy_generator

This installs three packages:

• build_runner, the tool to run code-generators
• envy_generator, the code generator
• envy_annotation, a package containing annotations for Envy.

Run the generator

To run the code generator, execute the following command:

dart run build_runner build

For Flutter projects, you can also run:

flutter pub run build_runner build

Note that like most code-generators, Envy will need you to both import the annotation (envy_annotation) and use the part keyword on the top of your files.

As such, a file that wants to use Envy will start with:

import 'package:envy_annotation/envy_annotation.dart';

part 'config.e.dart';

Creating a Config Model using Envy

An example is better than a long abstract explanation, so here's a typical Envy class:

// This file is "config.dart"
import 'package:envy_annotation/envy_annotation.dart';

// required: associates our `config.dart` with the code generated by Envy
part 'config.e.dart';

@envy
class Config {
  @variable
  static String apiBaseUrl = _Envy.apiBaseUrl;

  @variable
  static String get apiUrl => _Envy.apiUrl;

  @variable
  static bool get devMode => _Envy.devMode;

  @variable
  static int get threadsCount => _Envy.threadsCount;

  @variable
  static double get similarityDistanceThreshold =>
      _Envy.similarityDistanceThreshold;

  @variable
  static String? get missingOne => _Envy.missingOne;

  static String get testVar => 'test';
}

# This file is ".env"
API_BASE_URL=https://my.api
API_URL=$API_BASE_URL/guest/json-rpc

DEV_MODE=TRUE

THREADS_COUNT=3

SIMILARITY_DISTANCE_THRESHOLD=0.2

The following dart snippet defines a model named Config:

• Config has 2 properties: apiBaseUrl and testVar.
• Config has 6 getters: apiUrl, devMode, threadsCount, similarityDistanceThreshold, missingOne.
• Because we are using @envy, Envy will try to extract value for each property/getter which is marked by @variable.
• Getters and properties which are marked with the @variable have links to the _Envy class which holds extracted values from the .env file.

From this example, we can notice a few things:

• It is necessary to annotate our class with @envy or @Envy.
  This annotation is what tells Envy to generate code for that class.

• It is necessary to annotate each property/getter of the class with @variable or @Variable for which you need to extract value from .env file.
  This annotation is what tells Envy which variables to look for.

Supported types

Envy supports the following types: int, int?, double, double?, bool, bool?, String, String?.