envystic 0.2.0+2

Simplify and Secure Your Environment Variables (dotenv file or system) in Dart/Flutter.

Envystic

Envystic is a Dart/Flutter package that simplifies the management of environment variables (dotenv) and provides an extra layer of security. With Envystic, you can effortlessly handle environment variables in your Dart and Flutter projects, ensuring cleaner and more secure code.

Features

1. Easy Environment Variable Management: Envystic simplifies the management of environment variables by providing a convenient and structured way to define and access them in your Dart and Flutter projects.

2. Secure Variable Storage: Envystic allows you to provide an optional encryption key to obfuscate or encrypt the values of your environment variables, enhancing the security of sensitive information.

3. Annotation-Based Configuration: Defining environment variables is straightforward with the use of annotations. The Envystic and EnvysticField annotations help generate the necessary code for accessing your environment variables.

4. Custom Key Names: You can specify custom key names for your environment variables in the .env file, making it easy to reference them in your code.

5. Flutter and Dart Support: Envystic is designed to work seamlessly with both Flutter and Dart projects, allowing you to manage environment variables consistently across different types of applications.

Installation

Flutter Project

flutter pub add envystic && flutter pub add --dev envystic_generator build_runner

Dart Project

dart pub add envystic && dart pub add --dev envystic_generator build_runner

Usage

1. Import the envystic package into your Dart/Flutter file:

import 'package:envystic/envystic.dart';

2. Define an environment variable class using the Envystic annotation and the EnvysticField annotation for each desired variable:

part 'env.g.dart';

@envystic
class Env with _$Env {
  const Env();

  @override
  @envysticField
  String get key1;

  @override
  @EnvysticField(name: 'FOO') // The value from 'FOO' in .env will be used
  int? get key2;

  // ignored
  String get drink => 'Coffee';
}

3. Generate the environment variable class using build_runner:

dart run build_runner build

This will generate the necessary code based on the annotations in your codebase.

4. Access the environment variables in your Dart/Flutter code:

void main() {
  final env = Env();
  // Access environment variables
  print(env.key1); 
  print(env.key2);
}

Configuration

The Envystic annotation supports the following optional parameters:

• path: The path to the environment variables file. By default, it is set to .env'.
• encryptionKey: If provided, this encryption key will be used to obfuscate / encrypt the values. If not provided, a base64 encoding is applied to the values for a simple level of protection.
• keyFormat: Specifies the format of key names in the environment file (e.g., .env). Defaults to [KeyFormat.none].

Example

Here's an example of using the Envystic package:

import 'package:envystic/envystic.dart';

part 'env.g.dart';

@envystic
class Env with _$Env {
  const Env();

  @override
  @envysticField
  String get key1;

  @override
  @EnvysticField(name: 'FOO') // The value from 'FOO' in .env will be used
  int? get key2;

  // ignored
  String get drink => 'Coffee';
}


void main() {
  final env = Env();
  // Access environment variables
  print(env.key1); 
  print(env.key2);
  print(env.drink); // "Coffee"
}

EnvysticAll Annotation

The EnvysticAll annotation provides an automatic way to load all keys from the environment file without the need to specify them individually using getters.

Example:

import 'package:envystic/envystic.dart';

part 'env_all.g.dart';

@EnvysticAll(path: '.env.example', encryptionKey: 'EncryptMorePlease')
class EnvAll with _$EnvAll {
  EnvAll();

  @override
  @EnvysticField(
      name:
          'MY_SPECIAL_KEY') // This will be pulled from System environment variables if not exists in .env.example
  int? get specialKey;
}

void main() {
  final envAll = EnvAll();
  // Access all loaded environment variables
  print(envAll.specialKey); 
  print(envAll.key1);
  print(envAll.key2);
  print(envAll.foo);
  print(envAll.bar);
  ...
}

It is recommended to use the @Envystic annotation instead of @EnvysticAll. Using @Envystic allows you to specify only the fields needed, reducing class overload and ensuring better maintainability.

Methods

T get<T>(String envKey)

Retrieves the value associated with the given envKey from the loaded environment entries. The type of the returned value is inferred based on the actual field type.

Example:

final myValue = env.get<int>('MY_SPECIAL_KEY');

In this example, MY_SPECIAL_KEY is retrieved from the loaded environment entries as specified: integer. If the key does not exist or the value cannot be cast to the specified type, this method will throw an exception.

T? tryGet<T>(String envKey)

Tries to retrieve the value associated with the given envKey from the loaded environment entries. If the key does not exist or the value cannot be cast to the specified type, this method will return null instead of throwing an exception.

T getForField<T>(String fieldName)

Retrieves the value associated with the given fieldName from the loaded environment entries. The type of the returned value is inferred based on the specified generic type T.

Throws an exception if the fieldName does not exist in the loaded environment entries or if the value cannot be cast to the specified type T.

Example:

final myValue = env.getForField<int>('specialKey');

bool isKeyExists(String envKey)

Checks if the provided envKey exists in the loaded environment keys. Returns true if the key exists, false otherwise.

String? getFieldName(String envKey)

Gets the field name associated with the provided envKey. If the envKey exists, returns the corresponding field name; otherwise, returns null.

Author

itisnajim, [e-mail]

License

Envystic is available under the MIT license. See the LICENSE file for more info.